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Transcript of 58.0 CHEMICAL CLEANING SAFETY - naisinc.com Chemical Cleaning Safety... · Emergency procedures for...




    It is NASG's policy to control health hazards through elimination of the hazard, substitution of less toxic materials, and/or engineering controls to the greatest extend feasible. Where these are not possible, or while controls are being implemented, appropriate personal protection equipment shall to used to protect employees from hazards.

    The purpose of the NASG Chemical Cleaning Program is to establish uniform guidelines for protecting employees and complying with the requirements of OSHA pertaining to chemical cleaning processes.


    Supervisors must inform workers of hazards present in the work site and those that are not covered in this program. Employees must know the following information about each chemical or chemical group prior to its use:

    1. The name of the chemical and its hazardous component(s); 2. The health and physical risk(s) associated with the chemical; 3. Signs of release and symptoms of exposure; 4. How and when to use engineering controls and personal protective equipment; 5. Labeling and storage requirements; 6. Disposal procedures; 7. Emergency procedures for spills and exposures; and 8. Standard operating procedures (SOPs).


    General Chemical Cleaning Terms

    Acid - A material, which increases the hydrogen ion concentration in water. A material, which will neutralize basic (alkaline) solution. A material, which dissolves metals with the release of hydrogen gas. A material, which lowers the pH value in water solution. Acid Mineral - Examples, HCI- hydrochloric acid, H2SO4 - sulfuric acid, HF-hydrofluoric acid, H3PO4-phosphoric acid, HNO3-nitric acid, H2NSO3

    H-sulfamic acid.

    Acid Cleaning - (1) The removal of deposits from plant equipment through utilization of an acid solvent. (2) The use of a solvent which has a pH substantially below 7, commonly associated with the strong mineral acids such as hydrochloric acid, sulfuric, nitric, or phosphoric acids. Acid Organic - Examples, C6H8O7 citric acid, HCOOH formic acid, CH3

    COOH acetic acid. Organic Acids contain carbon in their structure.



    Acidity - (1) The characteristic property of those solutions, which have a concentration of hydrogen ions greater than 10-7

    moles per liter. (2) An expression denoting the predominance of hydrogen ions in a cleaning solution. An "acidic" solution of pH = 1.0 has a hydrogen ion concentration of 0.1 moles per liter.

    Acid Strength - The weight percent of the free acid in a cleaning solution. This is measured by titration using a pH end point just below the pH of any salt in the solution. Active Metal - A metal that is in the state where it tends to corrode. See opposite under Passivation. Alkaline - Having pH greater than 7. Alkaline Strength - The weight percent of alkaline material in solution: e.g., 2 % soda ash. Alkalinity - (1) The characteristic property of those solutions, which have a concentration of hydroxyl ions greater than 10-7

    moles per liter. (2) An expression denoting the predominance of hydroxyl ions in solution. A solution of pH equal to 7.0 has an equal quantity of hydrogen ions and hydroxyl ions and is said to be neutral. Above pH 7.0, hydroxyl ions predominate over hydrogen ions, and the solution is said to be alkaline.

    Alloy - An admixture of metallic components to give durability or other specific desired properties. Low Alloy Steel - Generally a steel, which contains less than 5 % of alloying elements such as nickel, chromium, manganese, etc. Ammonium Citrate - A salt of ammonium hydroxide and citric acid. Such salts are commonly prepared by mixing aqueous ammonia and citric acid solutions. There are three salts (mono, di, and tri basic). The desired mixture is usually specified by pH. It is customary to use pH 3,5, or 9. Anion - Ions that carry a negative charge and migrate to an anode. Such as C1-, SO4=, CO3=

    , etc.

    Anode - An electrode at which oxidation of the surface or some component of the solution is occurring. Aromatic - Name given to an organic solvent, which has a ring structure for its molecules. The opposite would be straight line (chain) structure. Austenitic - An alloy having a face-centered cubic crystal structure of the austenite phase of steel, the normal high-temperature phase of low alloy or carbon steels. Austenite is stabilized by nickel and manganese in sufficient concentrations so that it exists at low temperatures in some alloys, particularly 300 Series Stainless Steels. Austenitic SteeL - A stainless steel, which has 18 % chrome and 8 %, nickel added, sometime called 18-8 steel. This alloy is designated with a 300 series number (304,316,321, etc) and is highly susceptible to chloride stress cracking.



    Blend Filling - The preparation of a chemical cleaning solution by simultaneously metering water and chemical concentrate in appropriate proportions into a vessel to be cleaned. Block Valve - A valve designed to be either open or closed, as distinguished from a regulating valve. Cathode - The electrode of an electrolytic cell at which reduction occurs. In corrosion processes, usually the area at which metal ions do not enter the solution. Typical cathodic processes are cations taking up electrons and being discharged, oxygen being reduced, and the reduction from a higher to a lower valence state. Cation - A positively charged ion which migrates to a cathode such as Fe++,Fe+++,Na+


    Carbon Steel - Mild steel, 1010 or 1020 steel. Iron, which contains 0.1% (1010) or 0.2% (1020) carbon. Caustic Embrittlement - The form of stress-corrosion cracking occurring in steel exposed to alkaline solutions. (See stress-corrosion cracking.) Cavitation - Damage of a material associated with collapse of cavities in the liquid at a solid-liquid interface. Check Valve - A valve that confines the flow of a fluid to one direction. Chelating Agents - Ion or molecular species, such as gluconates, citrates, EDTA, NTA, that form stable complexes with cations such as Ca++,Mg++,Fe++,Fe+++

    . These products will dissolve calcareous deposits and rust accumulations without the use of acid solutions.

    Chemical Cleaning - The removal of deposits from industrial equipment by chemical means. Dissolution, emulsification, saponification, detergency, etc. Citric Acid: An organic acid, found naturally in citrus fruit and commercially made by sugar fermentation, noted for its iron chelation ability (H3C6H5O7


    Composite Drain Sample - Generally a sample of spent solvent obtained by continuously bleeding a portion of the draining solvent into a container. Cooling Tower - An enclosed structure for the evaporative cooling of water by contact with a stream of air. Corrosion - The deterioration of a material, usually a metal, because of a reaction with its environment. Corrosion Product: The compound formed as a result of corrosion processes; commonly an oxide, hydroxide, sulfide, chloride, etc. of the corresponding metal. Corrosion Rate - The rate of loss of metal expressed in millimeters penetration per year(mpy) or in inches penetration per year(ipy).



    Corrosion Fatigue - Simultaneous action of corrosion and changing stress in which a notch is formed progressively by chemical attack accelerated by applied cyclic or changing stress. Coupler - A chemical, which has the ability to form one miscible liquid from two immiscible substances. Crevice Corrosion - Corrosion that occurs at a crevice. Such crevices may be formed by contact with another piece of the same or another metal or with a nonmetallic surface. Usually corrosion resulting in areas covered by nonmetallic materials is called Poultice Corrosion. Deposit Attack - (1) Type of nonuniform corrosion that occurs under a deposit because of nonuniform access to corrodent. (2) The excessive corrosion that can occur under solid materials laid down on metallic surfaces. (3) Poultice Corrosion. Detergent - A surface-active agent, which lowers surface tension and promotes wetting and is capable of removing oils and greases. Defoaming Agents - (1) Chemicals, such as silicones, which suppress the tendency of solution, including cleaning solutions, to produce foams. (2) Substances capable of destroying foam. Dispersants - Chemicals, which tend to deflocculate particulate matter or particles and thus prevent or inhibit settling or sedimentation, e.g., polyacrylate. DOT - Department of Transportation. EDTA - Ethylenediaminetetraacetic acid. An amino tetracarboxylic acid, which is commonly used as the tetrasodium salt. EDTA is a particularly useful and effective chelating agent for most di-and tri-valent metallic ions.(H4C10H12O8N2


    Electrolysis -The chemical change in an electrolyte resulting from the passage of electricity. EMF - The electrical potential of a metal with reference to a standard electrode, usually H2


    Emulsification - The process of suspending very small globules of one liquid in a second liquid in which the first liquid is insoluble. Emulsions - Two phase cleaning solutions. Cleaning solutions generally consisting of an aqueous phase and a hydrocarbon phase formulated with suitable surfactants and couplers. Acidic Emulsions - Emulsions in which the aqueous phase is an acid material. Alkaline Emulsions - Emulsions in which the aqueous phase is an alkaline material. EPA - Environmental Protection Agency. Erosion Corrosion - A corrosion reaction accelerated by velocity of liquid or air abrasion.



    Exfoliation - A type of corrosion in which layers of corrosion product form below and parallel to the metal surface, causing the metal to be pushed out in "leaves." Occurs in Cu-Ni alloys in high-pressure boiler feedwater systems and on aluminum alloys. Ferric Ion Corrosion - The attack of base metal as a result of the oxidizing effect of ferric ions. This type of attack is frequently observed in localized sites when an acid dissolves ferric oxide. Ferritic Materials - Ferritic - having the body-centered cubic crystal structure of the ferrite phase of steel - the normal phase of low-alloy or carbon steel below the critical temperature after slow cooling from above the critical temperature. The term is sometimes used to designate chromium stainless alloys that remain ferritic at all temperatures (405,430,442,446). It is also used in other cases to designate steels that are not austenitic, i.e., are normally ferritic at low temperature. However, this may include steels that form martensite on fast cooling. Fill-And-Soak - A procedure for cleaning a piece of equipment in which the equipment to be cleaned is filled with solvent and allowed to soak until clean. Film Formers - Chemicals which, when used at low concentrations, tend to form ultra thin (mono molecular) films on material of construction. Such compounds are useful as agents to inhibit corrosive attack on metals during chemical cleaning. Flange Rating - Method of determining the maximum allowable working pressure for a flange. The higher the flange rating (150 lb, 300 lb, 900 lb, etc) the thicker the flange. Also there will be a change in the number of bolts and in the diameter of the bolt circle. Flare - A device for incinerating waste gases. Flash Point - The temperature at which the vapor above a heated portion of a flammable solvent momentarily ignites when a small pilot flame is passed above the surface. Flocculating Agents - Agents, which cause suspended matter to settle from solution by causing large particles to form. Foam Cleaning - (1) A technique whereby acid or alkaline cleaning solvents containing a special foaming agent are agitated with air or gas forced through units being cleaned. (2) The use of foaming agents such as detergents, to produce high volume, lightweight-cleaning solvents. Formic Acid - The simplest aliphatic monocarboxylic acid, often used in combination with other organic acids to remove iron oxide and mill scales.(HC O2


    Fouling - General term for any accumulation of insoluble material that impedes circulation or heat transfer. Galvanic Cell - Two or more dissimilar metals or alloys in contact with each other and with an electrolyte solution.



    Galvanic Corrosion - Corrosion associated with the current resulting from the coupling of dissimilar electrodes in an electrolyte. Also known as couple action. Hardness Deposits - Foulants which are comprised of calcium, magnesium, or sodium salts and are found generally in cooling water systems or boilers. An example would be calcium carbonate. Head - The height to which a liquid can be raised by a given pressure. Heat Exchanger - Equipment where heat is transferred between hot and cold fluids. These equipment units may be tube-in-shell, spiral, plate and frame or other designs. High-Chromium Steel - High chromium steels contain from 11 % to 30 % chromium and are designated by AISI types in the 400 series. A distinction is sometimes made in classification according to whether the metallurgical structure is ferritic at all temperatures. Alloys with low carbon and 14 % or more Cr or with 11-13 % Cr plus aluminum remain ferritic at all temperatures and do not harden on quenching. They may be called the "Chromium irons." Hydrogen Embrittlement - Reduction of the load-carrying capability by entrance of hydrogen into the metal. (As for example, through pickling or cathodic polarization.) Hydrogen Sulfide - A toxic gas, which is produced when acids contact sulfide solutions or sulfide-bearing deposits (H2


    Hydrostatic Test - Procedure whereby a vessel is filled with water and tested for leaks at greater than its normal operating pressure. Hydroxyapatite - A type of deposit often found in boilers treated with phosphates. It is chemical combination of calcium phosphate and calcium hydroxide. [Ca3(PO4)2]3Ca(OH)


    Hydroxyacetic Acid - Also known as glycolic acid, this hydroxy carboxylic acid forms chelate structures with many metallic ions. It is commonly used in combination with other organic acids for demill-scaling. (HO - CH2 - CO2


    Impingement Attack - Erosion of a metal surface due to a high velocity liquid striking the metal surface in such a manner as to prevent the establishment of a protective film on that surface. Inhibitor - A chemical substance or combination of substances which, when present in the proper concentration and forms in the environment, prevents or reduces corrosion by a physical, physico-chemical, or chemical action. Metals - Carbon Steel - Carbon steel is an alloy of iron and 0.05 - 1.78 carbon with enough manganese to insure hot workability. However, the term "alloy" is not used for carbon steel. It is reserved for steels with significant additions of other metals or with more than 1.0 to 1.5 % Mn. Carbon-Molybdenum Steel - Carbon moly steel is an alloy steel containing only molybdenum as a significant alloy element in addition to the carbon and manganese. In American practice, 0.5 % Mo is common C-Mo steel.



    Low-Chromium Steel - A low-chromium steel is a chromium steel with too little chromium to be classed as a stainless steel (i.e., less than 11 %). Sometime the 5 %, 7 %, and 9 % chromium steels are classified as intermediate chromium alloys and the term "low-chromium" reserved for less than 4 % chromium. Low and intermediate chromium steels in present-day operations always contain more than 1/2 % Cr, 1/2% Mo, so that they are actually Cr-Mo steels. Magnetite - An oxide of iron, Fe3O4

    , which is present in boiler deposits and mill scale.

    Mill Scale - A mixture of FeO (rust), Fe2O3 (hematite) and Fe3O4

    (magnetite) which forms on steel surfaces at high temperatures during fabrication.

    MSDS - Material safety data sheets Neutralization - The addition of an acid to a base (or vice versa) to adjust the pH of the resultant solution to near neutral. Acid+Base = Salt+Water Normality - A method of expressing the concentration of dilute analytical chemicals. Generally used for our titrants. Oxidation - Loss of electrons by a constituent of a chemical reaction. Oxide - A compound comprised of a metal and oxygen such as CuO, ZnO, or Fe3O


    Oxidizing Agent - A chemical having the property of receiving electrons from another element or compound. Thus, bromate salts are able to oxidize elemental copper to the ionic copper salt form and are so used in chemical cleaning. Passive - Describes a metal surface condition in which the metal substantially resists corrosion. Spool - A short length of pipe, flanged at both ends, used to replace a valve during chemical cleaning. Stainless Steels - Alloys which have nickel, chrome, or other components added to carbon steel for corrosion resistance. Stress Corrosion - Corrosion of a metal that is accelerated by stress, either residual in the metal or applied externally. Stress Corrosion Cracking - Premature cracking of metals produced by the combined action of corrosion and surface tensile stress (residual or applied). Surfactant - General term for "surface active" chemical species. Examples: wetting agents, detergents, emulsifying agents, foaming agents, etc. Surfactant species are generally large molecules or ions, with a hydrophobic part and a hydrophilic part. They tend to be adsorbed at oil-water and other phase boundaries. This causes lower surface and interfacial tensions. Wetting, emulsifying, detergency, etc.



    Toxicity - The tendency for chemicals or chemical systems to be detrimental to animal or plant life. Hydrogen sulfide and hydrogen cyanide are very toxic chemicals, as are mercury and copper compounds. Many biocides, useful in water treatment and chemical cleaning, are toxic to micro organisms and are used because of this property. Tuberculation - The formation of corrosion products at localized points on a metallic surface, the formation of localized nodules. Vapor Phase Cleaning - Denoting the use of chemicals or chemical systems in the vapor phase for cleaning, as distinct from the liquid or solid phase. Volume Percentage - (% vol) concentration expressed is the ratio of the volume of the item in question divided by the total volume of solution times 100. Weight Percentage - (% wt) concentration expressed as the ratio of the weight of the item in question divided by the total weight of the solution times 100. Wetting Agents - Any chemical which causes water or other liquid to easily penetrate into or spread over the surface of another material, e.g., detergents, soap. Personal Protective Equipment Required

    Hard Hat Safety Glasses ANZI 871 Chemical Splash Goggles Steel Toe Work Boots Ear Plugs (as required) Face Shield Chemical Resistant Rubber Boots Leather Gloves (as required) Chemical Resistant Rubber Gloves Chemical Resistant Slicker Suit Respiratory Protection (as required)

    Eye Protection Requirements Special Eye Protection Chemical goggles shall be worn in the immediate area were chemicals are being handled, mixed, or where possible chemical exposure exists. Immediate area can be any of the following.

    Within 15 feet of a pump Within 15 feet of pressurized hose Within 15 feet of Line Breaking Procedures. Within 15 feet of Blending Manifolds During Sampling Process Within 10 feet of Venting Operations



    Protective Clothing Requirements Protective clothing is required when handling high temperature (above 1400F), corrosive, hazardous, and or toxic chemicals or materials. Additional (including hard hat, safety glasses, gloves, steel toe footwear) Protective Clothing requirements for general chemical cleaning applications is as follows, unless otherwise noted in the procedure and job safety hazard analysis:

    Within 15 feet of a pump Within 15 feet of pressurized hose Within 15 feet of Line Breaking Procedures. Within 15 feet of Blending Manifolds During Sampling Process Within 10 feet of Venting Operations

    Hot Water Circulation Temperature (above 1400F) and within 15 ft of source or barricaded area.

    Hard Hat Safety Glasses Steel Toe Footwear Full Slicker Suit or Slicker Jacket that extends to knee level. Face Shield Rubber Gloves

    Acid or Alkaline Mixing, Neutralization & Circulation Citric Acid, EDTA, HCl, Formic, Sulfuric, Sulfamic, Nitric, Phosphoric Caustic Soda(liquid or dry) HAN, KOH, TSP, Lime, Sodium Meta Silicate, ABF

    Hard Hat PVC Acid Resistant Full Slicker Suit Chemical Splash Goggles Face Shield (during mixing procedures) Neoprene Steel Toe Rubber Boots PVC Rubber Gloves Respiratory Protection (as required)

    Mixing or Circulation of Ammonia Products and Associated Oxidizers Aqua Ammonia, Ammonium Bicarbonate, Sodium Bromate, Ammonium Persulfate

    PVC Acid Resistant Full Slicker Suit Neoprene Rubber Boots PVC Rubber Gloves Full Face Respirator or Half Face with Chemical Splash Goggles and Ammonia




    Mixing or Circulation of Hydrocarbon Solvents Diesel, Naphtha, Xylene, Kerosene, Light Cycle Oil, and Terpenes.

    Hard Hat PVC Acid Resistant Full Slicker Suit Fire Retardant Clothing (Nomex) Chemical Splash Goggles Face Shield (during mixing procedures) Neoprene Steel Toe Rubber Boots PVC Rubber Gloves

    Detergent and Surfactant Washes

    Hard Hat Chemical Splash Goggles Face Shield (during mixing procedures) Neoprene Steel Toe Rubber Boots PVC Rubber Gloves PVC Slicker Suit at temperature greater than 1400F.

    Job Planning The qualified person must approve all chemical cleaning procedures. Once the procedure and treatment technique has been established, subsequent approval is not required unless job scope changes. A written step by step job procedure will be produced. The minimum procedure will contain the follow:

    Safety Requirements: Equipment Load List Connection Points and Connection Size Chemical Requirements and Desired Circulation Strengths Special Chemical Handling Requirements Chemical Mixing Procedure Chemical Sample Points and Sample Intervals Minimum Circulation Time & Circulation Rates Disposal Method & Location

    Pre Trip Check List

    Written Procedure, Job Logs, MSDS Sheets Titration Kit & Sample Bottles Radios Tools



    Safety Equipment and First Aid Kit Equipment Check; pressure gauges, fittings, hoses, etc Chemical Inventory DOT Transportation Requirements

    Job Site While in the customers plant, you must follow their safety regulations as well as NAISG programs. The supervisor will contact the customer representative and review scope of work. The supervisor will also survey work location for any hazards or changes. The supervisor will obtain necessary customer work permits. The supervisor will conduct a pre-job safety and operations meeting. In this meeting the supervisor will instruct the crew on the following items:

    Area Safety Procedures Required Safety Equipment Safety Shower & Eye Wash Location within 25ft of

    pumping and mixing operations Outline Job Procedure Chemical Mixing Techniques and Hazards Assign Individual Task Assignments

    The supervisor will hold a pre-job meeting to discuss area hazards and review hook up procedures, discuss where equipment should be spotted, and assign crew responsibilities. Most chemical jobs require utilities (water, air, nitrogen, & steam) these will be located and run to the chemical mixing and pumping equipment. Verify the steam and water supplies will be adequate for the job. This tends to be a problem area and prolongs a number of relatively simple jobs. A check valve must be placed on all plant utilities to protect them from contamination with chemicals. The system circulation loop will be laid out and walked over. Check the integrity of all connections (fittings) before completing the hook up. If the union is worn, do not use it, replace it. The time you use replacing it will be considerably less than the time involved in cleaning a spill and attending meetings following a leak or spill. The hook up will include a sample point (pressure and temperature gauges), a heat source (exchanger or sparger), a connection for air or nitrogen, a reverse flow manifold and an alternate line to pump to waste disposal. The system (at a minimum) will have a valve at the discharge of the pump and the inlets/outlets of the system. This is to allow the system to be isolated from the pumping equipment in case of equipment or hose failure. The system will be set up with a double block and bleed valve arrangement. This allows the system to be isolated from the pumping equipment, and line to be de-pressurized prior to breaking, in case a leak develops. The system should have at least one vent at the system high point. If the system has a number of elevation changes, vents will be needed at each high point otherwise air pockets will form, restricting chemical circulation. The vent hoses should be vented outside the building or tied into a flare system. The reaction gases, usually hydrogen can be toxic and explosive. Be sure you and your crew understands the chemistry and the possible products (hydrogen sulfide and nitrogen compounds) of the chemical reactions.



    All fittings and temporary connections should be compatible with the chemistry in the system. The fittings should be schedule 40 or 80 carbon steel. Never use malleable iron, copper, copper alloy, brass, galvanized or aluminum fittings in your hook up. The fittings should be clean and in good condition. The externals should be painted to extend the service life and improve appearance. The thermometer and gauges should be installed last when hooking up and removed first when rigging down. Be sure to have extra fittings and O-rings for the hammer unions. Inspect all O-rings prior to tightening the union as this will help reduce the chance of chemical leaks. Be sure to install a flow meter on the discharge side of the pumping equipment. Be sure to check flow direction on the side of the meter. If the equipment being cleaned is being circulated through the truck tank, the return hose from the unit can be connected into the outboard suction of the pump, into the return on the side of the tank or into the top of the tank. If the return is in the top of the tank, it must be equipped with a tee and secured to the tank dome with a rope. The return hose (tee) must be below the liquid level in the tank. If the tee is above the liquid it will aerate an acid solution to generate highly corrosive ferric iron ions. Ferric iron corrosion can not be controlled with a corrosion inhibitor so it is imperative that we take steps to prevent its generation. Before you begin pumping, you must be sure the system is adequately vented and dome lids are open on the circulator. If the tanks or system are not adequately vented they may over pressure, rupture or collapse. The system should be filled with water and pressure tested to at least operating pressure. Pressure should be maintained for at least 5-10 minutes and all connections checked for leaks. A water supply should be near the pump for emergency wash downs from chemical exposures and spills. Washing the area with water will reduce the severity of skin burns and the corrosion on equipment. Place a collection bucket under the pump and sample points to collect solvent drips and vented chemicals. Before injecting chemicals a final meeting and system walk down will be completed. The supervisor will discuss the complete job procedure, safety concerns, flow paths, chemical requirements, chemical reactions, and emergency shut down procedures. The immediate work area should be barricaded and safety signs posted. Upon completion of any job, leave the work area in a clean condition. The work site should be spotless, even if it was dirty when we arrived. Pick up wrappers, coffee cups, empty chemical bags, and barricade tape. The area should be washed down with water and all utility hose rolled up and stored properly. Flush and drain all hoses; clean and grease all union connections; break apart any fittings that were made up special for this treatment. Be sure to check the system and valve positioning to assure the system is in a safe condition before leaving. Review the job with the customer (in detail) before having paper work signed.

    Chemical Hazards & Safety Considerations As in all aspects of business, there are certain hazards of the trade of which we must be aware in order to perform our job in a safe manner. Knowledge of these hazards is imperative in order to conduct chemical cleaning operations in a safe manner. While chemical cleaning we come into contact with a variety of deposits and are required to use a



    number of solvents which if handled improperly can present particular hazards to our personnel. There are certain safe handling practices which apply to all chemicals. They are listed below.

    1. Chemical goggles must be worn when handling hazardous chemicals. 2. Rubber suits and high rubber boots must be worn when handling chemicals which

    are corrosive, such as Sulfuric Acid, Sodium Bromate, Nitric Acid, Hydrofluoric Acid and liquid Caustic (Sodium Hydroxide).

    3. All chemical spills, whether on object or person, must be washed with large quantities of water. If the chemical is in the eyes, a continual eye wash with water is necessary for at least 20 minutes. If chemicals come in contact with other parts of the body, wash thoroughly with water and then with soap and water.

    4. Chemicals in unlabeled and / or broken containers should not be used or kept in storage.

    HCl ( Hydrochloric Acid or Muriatic Acid )


    H2SO4 Oxalic Acid

    ( Sulfuric Acid )

    Nitric Acid Citric Acid Phosphoric Acid Hydroxyacetic Acid Formic Acid Hydrofluoric Acid Sulfamic Acid Erythorbic Acid Ethylenediaminetetraacetic Acid

    Acids vary widely in properties and reactivity. Some like Sulfuric Acid are very dangerous. Others, like citric acid, are comparatively mild. Length of contact, strength and temperature will determine the severity of any contact. When diluting acids, the acid should always be added to the water. This is particularly true of the Sulfuric Acid:

    1. Acids cause burns to the eyes and skin. 2. Fumes and mist are harmful and, in sufficient quantities, will cause burns. 3. If concentrated Sulfuric Acid is spilled on any part of the body, wash off with large

    streams of water. When water is added to concentrated Sulfuric Acid, considerable heat is released. If insufficient water is not used at once, serious burns will result from the heat released and chemical reactions.

    4. Any fluorides produce immediate burns which are very painful and slow to heal. Fluorides should be immediately washed with water and medical attention secured.

    5. Store acids out of direct sunlight and away from oxidizing agents. Vent acid containers at least once a week, more often in hot weather.



    Caustic Soda (Sodium Hydroxide)

    Alkaline Chemicals

    Sodium Metasilicate - Pentahydrate EDTA flake or powder, Tetrasodium or Disodium EDTA liquid Tetraammonium or Diammonium Soda Ash (Sodium Carbonate) Disodium Phosphate - Anhydrous Trisodium Phosphate - Dedecahydrate Caustic Soda flake, chloride free (Sodium Hydroxide) Sodium Hydroxide Solution (50 % wt.) Hydrazine Potash (Potassium Hydroxide) Aqua Ammonia (Ammonium Hydroxide)

    Alkaline chemicals are the direct opposites of acids.

    1. Alkaline chemicals have a soapy feel and cause burns to the skin and eyes. Their dust and mist is equally harmful. Wash continually with water until all the chemical is removed and there is no soapy feel to the area exposed.

    2. Keep Chlorinated solvents away from Caustic Soda and Sodium Hydroxide. They react to form materials which explode spontaneously. (See part on special handling precautions for Chlorinated solvents.)

    3. Never dissolve Caustic Soda or Caustic soda in hot water. Large amounts of heat are released when these materials dissolve, and they could cause hot water to boil. Always use cold water to mix dry caustic.

    4. Store alkaline materials away from acids and chlorinated solvents and keep dry. Mixing Dry Caustic Soda The use of dry caustic soda flake or beads is restricted to mixing applications involving water and other capable alkaline materials for the purpose of formulating a degreasing solution, or to make a dilute liquid caustic solution to neutralize acid solutions. DRY CAUSTIC MUST NEVER BE ADDED TO ACID SOLUTIONS. The addition of dry caustic materials must take place under the following conditions.

    Dry caustic must be added to water below a temperature of 1500F. Dry caustic must be added to water via a mixing tank. The water solution must be

    circulated at a minimum flow rate of 100 gpm and have an inline temperature gauge for continuous monitoring.

    The maximum allowable caustic solution concentration using dry caustic is 10% by weight.



    Oxidizers Oxidizers are incompatible with certain chemicals and must not be allowed to come into contact with these chemicals. Oxidizing agents are peculiar in that they have both flammable and explosive characteristics. Oxidizing agents compromise a group of chemicals which are more dangerous than any other chemicals used. Problems that can result include: fire; evolution of toxic gases; and under certain conditions, even explosions can occur. For these reasons, oxidizers must always be isolated from all other chemicals during transportation or storage and we must be especially careful to assure tank cleanliness to avoid co-mingling of other chemicals with oxidizers. In general, oxidizers should not be allowed to contact Acid Solutions, Organic Compounds, Reducing Agents and Copper or Copper Alloys. In the event leaks develop and spillage of oxidizers occur, we must contain these spills to avoid contact with other chemicals and the oxidizing effects must be neutralized the appropriate reducing agent. The safety precautions for handling these oxidizing agents are:

    1. Store separate from acids, reducing agents, inhibitors, surfactants, foaming agents, emulsifiers (see following pages), and organic materials of all kinds, especially oil and grease. Keep dry and out of direct sunlight.

    2. Wear rubber suits, high rubber boots, and rubber gloves. Be sure all are free of oil and grease. DO NOT USE CLOTH OR FABRIC GLOVES.

    3. Do not measure or shovel with anything which could contain even small amounts of oil, grease, or organic material.

    4. Be especially careful to empty containers completely. Keep used containers separated from other containers. Haul off immediately and burn. DO NOT REUSE UNDER ANY CIRCUMSTANCES.

    5. If oxidizers are spilled, no matter how small in amount, wash the area with large amounts of diluted Sodium Sulfite solution. Do not wash to an area where the water could later evaporate and leave the oxidant.

    6. If spilled in an area where it cannot be washed, try to sweep the chemical into a container and then wash down the area with adequate Sodium Sulfite. Avoid any oil or grease.

    7. Safe disposal of Sodium Bromate or Potassium Permanganate solutions in truck tanks can be accomplished by the following procedure: Add enough water and agitate to dissolve all solid materials in the vessel. Estimate the amount of Bromate in solution and add 2 1/2 pounds of Sodium Sulfite for each pound of Bromate. The sides of the tank should be washed down and the mixture agitated. By following this method, the Sodium Bromate will be reduced to a non-oxidizer. Dump this solution directly into the customer designated disposal location. (Sodium Sulfite should not be allowed to get wet prior to mixing with the Bromate solution as it will pick up oxygen from the water, making it ineffective for reducing Bromate.) Use 0.55 pounds of Sodium Sulfite per pound of Ammonium Persulfate. If spilled on wood as on a dock or truck bed, the wood should be kept wet while it is removed and burned.

    8. If unsure about what to do, keep wet and contact your regional chemical manager for further instruction.

    9. Some of the oxidizing agents are also acids and include Chromium Trioxide, Nitric Acid, and concentrated Sulfuric Acid. Handling precautions for these oxidizing acids



    include those for the oxidizing agents plus the precautions which apply to other acids. In addition, the following must be observed.

    Oxidizing acids are especially corrosive to the skin and cause severe burns which are slow to heal. Chemical resistant rubber suits and rubber boots must be worn. Any spills must be washed with large amounts of water since these oxidizing acids generate heat when diluted with water. Large quantities of water are necessary to overcome this heat generation.

    Reducing Agents Reducing agents are the direct opposites of oxidizing agents. Reducing agents are fairly easy to handle, but they must be kept away from and stored away from oxidizing agents. In addition, Formic Acid should be handled as an acid material.

    Formic Acid Sodium erythorbate Stannous Chloride - Anhydrous Thiourea Sodium Sulfite Hydrazine Oxalic Acid Sodium Thiosulfate

    Aqua Ammonia, Ammonium Carbonate, Ammonium Bicarbonate, and Anhydrous Ammonia These materials are characterized by their strong ammonia odor.

    They are somewhat alkaline and should be treated as such. The Ammonia they release is toxic and has a maximum allowable concentration in

    air of 100 PPM. Store away from acids and out of direct sunlight. Vent drums of Aqua Ammonia , especially in hot weather. Check the Health Hazard

    Data Sheet for the toxicity and physical reactions and effects from exposure. When venting drums, slowly crack the bung and let the pressure escape slowly. Opening the bung rapidly can cause the Ammonia to erupt from the drum. Wear a full slicker suit, rubber gloves, and face shield and goggles along with a respirator when venting or handling Ammonia drums.

    Chlorinated Solvents The chlorinated solvents have toxic vapors. Their maximum allowable concentration in air are:

    Trichloroethylene 100 ppm Perchloroethylene 100 ppm Ortho Dichlorobenzene 50 ppm



    Chloroethene Nu 500 ppm Methylene Chloride 200 ppm

    When vapors of chlorinated solvents burn, Phosgene Gas is formed. Therefore,

    smoking is forbidden when using these solvents. Trichloroethylene must be kept away from Caustic Soda as explosive products are

    formed. Vent drums at least once a week and store out of direct sunlight.

    Inhibitors Inhibitors are used in conjunction with acids and include:

    Rodine 213/214 Cronox 240 Rodine 2000 AKI 100 Rodine 31A Rodine 95 Cronox 230 Rodine 145 Rodine 51

    Some inhibitors have low flash points and should be protected from sunlight, extreme

    heat, and open flames. Inhibitors should be stored separately from oxidizing agents (minimum of 20ft). After they are diluted in solution, inhibitors typically will not react with other

    chemicals. Inhibitors are mixtures of different compounds, they have a tendency to separate

    when allowed to stand. It is therefore advisable to mix the inhibitor drums prior to use if only partial drums are used.

    Surfactants, Emulsifiers, and Foaming Agents All of these are fairly simple to handle, but they must be kept away from oxidizing agents.

    In this group are the following:

    Dowfax 2A1 (alkaline) Dowfax 3B2 (alkaline or acidic) Surfonic N 95 Vanwet 9N9 Aquet 921 Aquet X-21



    Organic Solvents Organic solvents are flammable and may have low flash points. They should be stored away from oxidizing agents and should be protected from direct sunlight, extreme heat, and open flames. Where a flash point range is given, the lower temperature must be assumed to apply, unless an MSDS is available and states a different flash point.

    SOLVENT FLASH POINT oF Kerosene 100 - 120 Fuel Oil #1 100 - 120 Fuel Oil #2 150 - 175 Diesel Oil 150 - 175 Benzene 12 Acetone 3 Methyl Alcohol 60 Naphtha 100 - 200

    Sulfides Sulfide deposits may be found in a number of plant processes. More commonly however, they are found in natural gas treating plants, refineries and paper mills. When these sulfide salts come into contact with strong mineral acids they will react to liberate H2

    All gases liberated will be routed to caustic scrubbers, plant flare systems or a combination of both.

    S gas which is extremely toxic and can cause death in minutes when concentrations exceed 1000 p.p.m. Precautions that will be observed when cleaning systems containing sulfides include:

    Operable H2

    Additives, such as formaldehyde can be added to react with the H

    S monitors must be worn by personnel in the vicinity of the chemical cleaning.

    2S and eliminate the evolution of H2S gas. When using glyoxol to remove the H2

    All personnel in the vicinity of the chemical cleaning should be alerted to the possibility of an H

    S we must wear full face shields and chemical cartridge respirators.


    All chemical cleaning personnel must be H

    S release and should be made aware of the location of SCBA air packs or an equivalent source of rescue pack.


    All jobs with the potential for HS certified.


    S should be staffed with a minimum of three (3) crew members per shift.

    Oxides of Nitrogen Passivation solutions commonly contain Sodium Nitrite. Since we use the same pumps and circulators for circulating both passivation solutions and acid solutions there is a possibility that residue from the previous cleaning step can come into contact with the Sodium Nitrite solution. When this occurs, a brown toxic gas known as NOx will be liberated. The need to thoroughly rinse our truck tanks, headers, and hoses before adding different chemicals cannot be overemphasized. When passivation solutions containing Sodium Nitrite are acidified, NOx gas will be released. For this reason, the Sodium Nitrite should be reduced with Sodium Sulfite prior to neutralization. One pound of Sodium Nitrite requires 3.0 pounds of Sodium Sulfite to reduce it to a point where NOx evolution does not



    occur. Also, when certain scale deposits are contacted with Nitric Acid, large quantities of NOx gas will be liberated. If involved in a cleaning job using Nitric Acid, be sure that the deposits and metallurgy are compatible.

    Toxic Chemicals Some of the chemicals that are required in the chemical cleaning business are recognized as being toxic at certain exposure levels and some are reported to be carcinogenic in tests with animals. Recognizing this fact, you can appreciate the requirement for special safety equipment and warrant special warnings: Completely read MSDS before handling or mixing any of these chemicals.

    Hydrazine Oxalic acid (poison) Formaldehyde Chlorinated hydrocarbons Inhibitors containing propargyl alcohol Thiourea Aromatics

    Asphyxiants It is sometimes necessary to recommend placing an inert gas to blanket a vessel that we may be cleaning in an attempt to exclude all oxygen from the system. Without oxygen, rust cannot occur, combustion cannot take place and life cannot be sustained! We must never enter a vessel that has not been checked with appropriate oxygen monitors and combustion monitors.

    Nitrogen gas is commonly sparged into the liquid to produce the foam. As it exits from the water box, dangerously low levels of oxygen can exist. Personnel required in the vicinity must wear positive pressure fresh air masks.

    When contacting systems containing heavy deposits of calcium carbonate with an acid solvent, large quantities of CO2

    Oxygen will be excluded and present an asphyxiation hazard

    gas is liberated. This can be hazardous for two reasons:

    If the system is not properly vented an overpressure condition can develop resulting in rupture of the vessels or circulating hoses.

    Flammable Solvents & Flammable Gases There is always the possibility of flammable gases from the process or system that we are cleaning. We should work in partnership with our customers to assure that the system we are cleaning has been completely isolated and tests should be conducted with explosion meters to assure that no combustible gases are present. There is however another source of flammable gas of which we must be aware. Combustible solvents are sometimes required to remove heavy deposits of organic materials from process type equipment and storage tanks in refineries, gas treating plants and petrochemical plants. Sometimes these solvents are used as a cutter stock to thin the heavy crudes to a pumpable consistency. The following are safety precautions that we can take to minimize the fire hazard:



    Select the solvent with the lowest vapor pressure When possible use an aqueous emulsion of the selected solvent to reduce the

    concentration of solvent. Avoid excessive heat, keep the vapor pressure of the solvent at a minimum. Ground the circulating truck to the equipment being cleaned. Exclude air from the vapor space above the solvent with a nitrogen gas blanket. Alert plant safety personnel of the hazards so they can arrange a fire watch. Eliminate open flames in the cleaning area. Be certain fire extinguishers are nearby,

    operable and filled. Hydrogen gas may be generated any time an acid contacts a metal. Small quantities

    are always generated however and can accumulate in head spaces or at vent lines. For these reasons we should never allow smoking in areas where chemicals are mixed or are circulated, and smoking and open flames should never be allowed near vent lines of systems containing cleaning chemicals. Hot work should never be performed on lines that contain acid solution and should be thoroughly flushed with water prior to hot work.

    Hydrofluoric Acid This chemical is particularly dangerous and must be handled very carefully. Typically we use Hydrofluoric Acid to remove silica deposits. Our most common method of contact involves adding Ammonium Biflouride to acid solutions which generate mild concentrations of HF Acid. We may also be involved with Hydrofluoric Acid when cleaning alkylation units since HF is often used as the catalyst in these units. When skin tissues contact Hydrofluoric Acid, the HF acts to bind Calcium in whatever tissues are brought into contact with it. Since Calcium is necessary for cellular life, its binding or precipitation will bring about cell death in the contacted area in a short period of time. If you come into contact with this chemical you should immediately flush the area contacted with copious quantities of water and then seek medical attention for further treatment.

    Heat of Reactions-When Will Heat Be Liberated? Extreme exothermic reactions and splattering can occur when mixing certain chemicals. The following are examples of which you should be aware:

    Neutralization of acids with bases (Alkalies) -- addition of any acid to a base or visa versa will generate some heat. When concentrated solutions are mixed, the heat generated is more extreme than when dilute solutions are mixed. An acid / basetitration will generate an insignificant amount of heat, however neutralization of 20 wt % HCl with 50 wt. % Sodium Hydroxide will result in a temperature of greater than 150 oF. This is known as the heat of neutralization.

    When a solute dissolves in a solvent, energy is either evolved or absorbed. This reaction, sometimes referred to as the heat of solution, can sometimes generate a significant amount of heat. Two chemicals which we handle are notable in this regard: Sulfuric Acid addition to water and Sodium Hydroxide addition to water both evolve significant quantities of heat. Addition of sufficient quantities of Sulfuric Acid to water can easily elevate the temperature of the resultant solution to the boiling point. Addition of water to Sulfuric Acid results in violent splattering and evolution of heat. We are required to mix Sulfuric Acid and water in many instances. Remember



    though that we should always add acid to water and never water to acid. This rule applies to all acids, but especially to Sulfuric Acid.

    General Chemical Cleaning Procedure

    Pre-Trip Inspection Travel to Location Contact Customer Review Scope of Work with Customer Complete Job Safety Analysis Hold Tail Gate Safety Meeting/Operations Meeting

    Customer Safety Policy & Rules Recognize Job Hazards Review Safe Work Practices Review MSDS, PPE, First Aid Location Emergency Procedures, Eye Wash & Safety Shower Locations, Spill

    Control & Clean-Up, Evacuation Routes Spot Equipment and Chock Vehicle Wheels Hookup and Inspect all Hoses and Fittings: No Visual Braids or Bubbles Check Boss Clamps or Crimped End Check Hammer Unions Tight Check O-Ring No Cracks or Flat No Galvanized, Copper, Copper Alloys, Brass or Aluminum Fittings Check Quarterly Hose Testing Color and Pressure Ratings

    1st Green 2nd Orange 3rd Yellow 4th

    Label Client Utilities and Install a Check Valve on any Item Under Back Pressure Blue

    Barricade Work Area Ground Pumping Equipment Leak Test with Water to 110% of Cleaning Pressure. Repair Any Leaks Use Proper Personal Protective Equipment Perform Chemical Treatment Establish Circulation, Blend Concentrated Chemical Into Water Vent System Prevent System Overpressure Begin Heating to Treatment Temperature Perform Chemical Analysis Testing Drain System, Vent System to Avoid Pulling a Vacuum on the System. Rinse System Flush All Hoses & Tanks Rinse All Empty Drums



    General Centrifugal Pump Engagement and Operational Procedures Minimum requirements for centrifugal pump operations.

    Functioning Pressure Gauge on Discharge Pipe. Discharge Valve Vent valve on Pump Volute / on Highest Point Suction Isolation Valve Drip Pan or Bucket

    1. Pump out of Gear or Engine Off Check System Integrity. Are all hose properly secured and are all minimum pump requirements met.

    2. Check PPE Requirements and Barricade Area 3. Start Engine but do not engage pump. Be sure pump discharge valve is

    closed. Slowly open suction isolation valve to allow water to flood the pump suction and volute. Slowly crack pump vent valve and bleed air and water into bucket or drip pan. Once all air has been bled from the pump, close vent valve and fully open suction isolation valve.

    4. Engage pump drive or PTO. Be sure discharge valve is closed. Check for pump shaft rotation and pressure gauge. Check pump seal and suction line. Shut down and repair any leaks.

    5. Slowly increase engine and pump rpm. Pressure gauge should begin to build pressure. Continue to increase rpm/engine speed until desired discharge pressure is achieved. Minimum discharge pressure should be 50 psi.

    6. Once desired discharge pressure is achieved, slowly open discharge valve. You may have to continue to increase pump rpm/engine speed to maintain discharge pressure.

    7. Check system integrity and repair any leak as necessary. 8. Continue pump desired circulation rate and discharge pressure. 9. If at any time the pump loses discharge pressure. Close discharge valve,

    decrease pump/engine speed to an idle, disengage pump, close suction isolation valve. Check suction supply. If supply is good restart pump using above start-up procedure.

    10. If pump does not operate properly, notify your supervisor immediately.

    General Pump Shut Down Procedure 1. Before shutting down any circulation be sure to flush pump and chemical hoses with

    water. Be sure all steam, water and chemical supply lines are isolated and turned off.

    2. Reduce pump/engine rpm to an idle 3. Close pump discharge valve 4. Take pump out of gear and turn engine off. 5. Open pump low point drain and crack high point vent and allow pump and suction

    line to drain into buckets or drip pan. 6. Once pump and suction lines are drained close drain valve



    Equipment Flushing All chemical cleaning equipment should be thoroughly flushed following any chemical circulation. The flushing procedure is best done as the final step of the chemical circulation process. Be sure to flush all equipment including tanks and hoses with a clean water source. The flush water should be pumped into the same location as the spent chemical cleaning solution. To assure proper flushing check the pH of the flush water. The pH should be between 6-10. Diaphragm Pumps Diaphragm pumps are positive suction pumps, meaning they will draw liquid into the pumps and therefore do not require a pressurized suction. This means they can draw liquid from drum or tanks below the level of the pump.

    Minimum Requirements for diaphragm pump operation

    1. All pumps should have an air control valve on the pump. This will allow a single operator full control of the diaphragm pump. The discharge side of any diaphragm pump should have a spool piece with a nipple and isolation valve installed to bleed off pressure and drain discharge hose.

    2. Prior to pumping any chemicals each pump should be tested. This test is to confirm the proper suction and discharge configuration as well as pump function. Confirm pump metallurgy and chemical compatibility.

    3. If the pump discharge is open ended into a tank. Secure pump discharge end by installing a circulation tee and secure hose with a rope.

    4. Testing of a diaphragm pump should consist of pumping 10-15 gallons of water from buckets to the designated chemical injection point. This will confirm the pump is capable of proper chemical injection.

    5. Once the pump has been tested and any leaks have been repaired. Be sure proper PPE is being used. Begin chemical injection, slowly open air supply to start pump operation. When flow is established increase air supply to desired pump flow rate.

    6. Once chemical injection is complete, flush pump and hoses with a minimum of 15 gallons of water using the same procedure for testing pump. Once all water has been pumped allow the pump to run dry to assure the suction line is completely empty.

    7. Turn off pump and air supply. Always ensure the discharge side of the diaphragm is depressurized. Open vent valve and drain discharge line before rigging down hoses.

    Loss of Circulation Loss of circulation of a solvent may occur for a variety of reasons: i.e. Unexpected valve closure; loss of flow to the pump suction; engine or motor failure. Should this occur the steam exchanger or sparger will quickly reach the temperature of the steam supply and any liquids in the system may flash to steam. This could result in an over-pressuring of hoses, and potential hose rupture. Therefore, the first thing an operator should do in the event of flow loss is to turn off the steam supply. This should be done in a deliberate fashion, but avoid too rapid a closure to prevent a steam hammer effect. Following this, the discharge and return valves should be closed to isolate the system and the flow loss problem corrected.



    Check Valves When blend filling a system there are typically three supply sources: condensate water, chemical concentrate and steam. Each of these supply sources will be delivered at some pressure and they will be flowing against the back pressure of the system. As the system fills and the back pressure increases, it could be possible to exceed the pressure of one of the supply sources. Should this occur, the supplies will take the path of least resistance and flow to the low pressure source. Without properly directed check valves on all of these sources, several scenarios could occur:

    1. Acid concentrate could flow through the condensate pump to the condensate storage tank

    2. Acid concentrate could flow into the steam supply line if the steam pressure were sufficiently low.

    3. Steam could flow through the condensate pump into the condensate storage tank. 4. Steam could flow through the circulator pump into the chemical concentrate storage. 5. Condensate could flow into the steam supply line. 6. Condensate could flow through the circulator pump and into the chemical

    concentrate storage.

    All of these may sound like unlikely scenarios, but they may occur. As a minimum, check valves should be installed on the steam supply line, at the discharge of the condensate pump and at the discharge to the system.

    Sparger Location If a steam sparger is used for heating circulating water, cleaning solvent, or for heating while blend filling, the steam sparger must always be positioned at the discharge of the circulating pump. Never sparge steam into the suction side of a pump!

    Steam Initiation When opening a steam supply line, the line will be filled with condensed steam until it has been purged out of the line. Always open the line slowly, bleed off the condensed water and allow the temperature of the supply line to rise slowly to the final steam temperature.

    Hard Pipe Any chemical cleaning conducted at temperatures greater than 200o

    F should be hard piped.

    Steam Entry Point on a Blending Manifold Acids are often blended with condensate water and heated with steam during injection into a system. When this type of fill is conducted, always inject the acid downstream of the steam and condensate to avoid inhibitor degradation and excessive corrosion. Chemical Cleaning Hoses All chemical cleaning hoses will be visually inspected and pressure tested to expected working pressure before every chemical cleaning treatment. The inspection and testing should include the following.



    1. Visually inspect the hose. Check for quarterly pressure test band. Check the hose for large cracks, gouges, bubbles in cover, kinks, flattened spots and loose braids. If any of the above conditions are found remove the hose from service.

    2. Check the hose end and fitting. Check the hose end for slippage, misalignment, and /or scored areas. If the hose endings are loose or shows signs of erosion and pitting remove from service. Check the O-ring on the hammer union. If it is flat or cracked replace. Confirm all hammer unions tight and boss clamp assemblies are tight.

    3. Fill the system with water and slowly increase pressure to expected working pressure. Check each hose connection for leaks. If you find a leak tighten connection or replace hose.

    4. If any hose is damaged or leaking , remove immediately and identify with a defective hose tag. Notify supervisor of defective hose. The supervisor will make a job log entry indicating hose serial number and nature of hose failure. The deflective hose should be placed in the deflective hose bin immediately upon return to division office.

    *Any hose that has been removed from service must be repaired by an approved hose vender and undergo hose testing procedures.

    Quarterly Testing In addition to job site pressure testing and inspection, all chemical cleaning hoses will undergo a quarterly testing program. The quarterly testing program will consist of a visual test of hose integrity, outer cover, tube structure, and coupling. Following visual inspection, the hose will be pressure tested to 1-1/2 times maximum working pressure for the hose. The hose will be held at pressure for a minimum of 30 seconds. The hose serial number will be used to monitor and track hose testing records. The person performing hydrotest operations will be responsible for completing hose testing.

    Approved Chemical Cleaning Hoses

    Goodall N-2700 KemFlex 2000 -40 to 180 0F 2 / 3 200 psi

    Gates 45 HW -30 to 2000F 2 / 3 200 psi

    Goodyear Viper -30 to 2500F 2 / 3 200 psi

    304 or 316 Stainless Steel Braided Hose

    Hose Ends All chemical cleaning hoses will be outfitted using one of the following configurations. All chemical cleaning hoses will have either stainless steel, or hastalloy king nipples and associated components. No other metallurgy is acceptable. UNDER NO CIRCUMSTANCES SHOULD BRASS OR ALUMINUM FITTING BE ALLOWED ON ANY CHEMICAL CLEANING HOSE.

    The hose end couplings will have one of the following configurations. Trilock or mechanical banding is not acceptable.



    4 Bolt Dixon Boss Clamp with Male NPT Nipple (Carbon Steel or Stainless Steel) Hydraulic Internally Expanded Male NPT Nipple (Stainless Steel) All hydraulic

    expanded king nipples must be installed by hose manufacturer and be certified and pressure tested.

    All hose coupling will have Huber Figure 300 Hammer Unions or Bolted Flange. The coupling system will be made of carbon steel or stainless steel.

    No camlock hose ends will be allowed on the pressure side of any chemical cleaning circulation. Camlock hose end will be limited to chemical transfer operations with a pressure limitation of 10 psi. All rental hoses must meet the above guideline for chemical cleaning applications and meet all pressure testing guidelines prior to reaching the customers job site.

    Procedure For Neutralizing Acid with Caustic Soda

    In contact with the skin or eyes, caustic soda will cause serious burns unless prompt action is taken. For this reason, every precaution must be taken to prevent skin and eye contact with caustic soda. Adequate protective clothing and equipment must be worn at all times and great care must be taken to prevent the caustic from splashing or splattering when handling or preparing solutions.

    Safety Considerations

    Before beginning neutralization the following P.P.E. must be worn to protect the individuals should an incident such as a hose rupture, violent reaction or spillage occur. Also, there must be a source of running water or a safety shower in the immediate area. PPE: Hard hats, face shield, slicker suit or acid suit (top & Bottom), rubber boots (slicker suit pant legs over boots), rubber gloves, and chemical splash goggles. Only liquid caustic up to 50% maximum concentration can be used to neutralize acids. Written approval of the Regional Chemical Cleaning Manager or the Field Services Group Manager must be obtained to use dry caustic to neutralize acids.

    1. Establish agitation, recirculation, or flow in the neutralization tank vessel, or piping. 2. Check the temperature of the acid if it is above 150oF it must be cooled down to


    3. Monitor the temperature while neutralizing if the temperature reaches 180F maximum before you can start neutralization.

    oF STOP--DO NOT ADD ANY MORE CAUSTIC! You must cool the solution down to 150o

    4. While mixing the acid to be neutralized,

    F again before resuming neutralization. You will need a heat exchanger or cold dilution water to lower the solution temperature. Adding additional caustic above this temperature may cause localized boiling and or eruption of the acid from the tank dome or vents.


    5. Safe addition rate of liquid caustic into the acid are dependent on temperature rise and not gallon per minute of liquid caustic injection. The larger the volume to be

    add the liquid caustic into the agitated flow of the acid. This can be done with a barrel pump, small diaphragm pump, or other source, but the injection hose must have a tee on the end of it or a blending manifold in line and be fastened securely so that the end of the hose can not work its way out of the tank.



    neutralized the faster the rate of injection can be, but the temperature rise should not be more than 10o

    6. No one is allowed on top of a tank while neutralizing is being performed. The neutralizing process must be stopped when anyone goes on top of the tank to check levels or other conditions.

    F every five (5) minutes.

    Commercially available as:

    Caustic Soda - NaOH FACTS

    Dry material 100 % as flakes, beads, or solid in 50 # bags, 100 # bags or drums, and 400 # drums.

    Liquid as 20 % or 50 % material in 55 gal. drums or bulk.

    Freezing Point:

    1. Dry -- no problem 2. Liquid 20 % -10 o

    3. Liquid 50 % +55 F o

    Equivalent pounds of dry per gallon of liquid:


    1. Liquid 20 % = 2.035 pounds per gallon 2. Liquid 50 % = 6.364 pounds per gallon

    Heat of Dilution assuming no radiant heat loss:

    1. Using dry caustic making a 5 % solution +20 o

    2. Using dry caustic making a 10 % solution +45 F o

    3. Using 50 % liquid making a 5 % solution +12 F


    4. Using 50 % liquid making a 10 % solution +18 F o

    5. Using 50 % liquid making a 15 % solution +38 F


    6. Using 50 % liquid making a 20 % solution +48 F


    Heat of Neutralization assuming no radiant heat loss:


    1. Using dry caustic and 5 % HCl + 54 o

    2. Using dry caustic and 10 % HCl +110 F


    3. Using 50 % liquid caustic and 5 % HCl + 38 F


    4. Using 50 % liquid caustic and 10 % HCL + 80 F


    5. Using 20 % liquid caustic and 5 % HCl + 30 F


    6. Using 20 % liquid caustic and 10 % HCl + 50 F o

    7. Using 98 % Sulfuric Acid and 5 % Caustic + 43 F


    8. Using 98% Sulfuric Acid and 10% Caustic +100 F o

    9. Using 98% Sulfuric Acid and 15% Caustic +124 F


    10. Using 31 % HCl and 5 % Caustic + 37 F


    11. Using 31 % HCl and 10 % Caustic + 68 F o

    12. Using 31 % HCl and 15 % Caustic + 80 F





    By subtracting the temperature rise as listed above from 180 o

    f you can determine the maximum safe starting temperature for neutralizing hydrochloric acid.

    Hydrogen Sulfide Special Safety Requirements General Cleaning Procedure and Safety Guidelines

    During the chemical cleaning process, hazardous byproducts may be generated. The most prevalent is Hydrogen Sulfide. Extreme caution should be administered.

    Special Safety Concerns

    Emergency Action Plan For Chemical Cleaning Operations Involving Potential H2

    Due to the potential of hydrogen sulfide (H

    S Exposure

    2S) exposure during many chemical cleaning processes, it is essential that there be a pre-determined plan of action in the event of an accidental release of H2


    This emergency action plan will accompany the job plan for any job in which a potential for H2

    S exists. This plan will be reviewed as part of the pre-job safety brief at the start of each shift on every job. All crew members must be present and will sign the bottom of the form.

    Prior to the start of the shift each crew member will be assigned specific responsibilities related to the emergency action plan.

    1. Identify chemical hazards of the process unit.

    Pre-Job Planning

    2. Identify cleaning chemicals and any associated hazards. 3. Identify required personal protective equipment (PPE) 4. Insure only trained, qualified personnel are used. 5. Insure all required PPE and other required safety equipment is available and

    serviceable. 6. Assign, by name, crew member responsibilities during an emergency. 7. Establish emergency communication procedures between crew, other

    contractors and plant personnel to include phone numbers, etc.



    A. Self Contained Breathing Apparatus (30 min. SCBA) 2 per job site or supplied air with 2 five minute escape packs (each job within a single unit does require a separate SCBA).

    Required Emergency equipment

    B. Toxic Gas Meter - 1 per job site (for H2C. Personal Exposure Monitor Badges - each employee.

    S use a Gas Tech GX-82)

    D. Emergency Alarm Device - Air horn (canned air) or equivalent. E. Other monitoring/protective equipment necessary for any other identified F. hazardous condition. G. Have a sign posted on each job site indicating H2

    S in process equipment.

    1. SCBA spotted upwind of barricaded work area.

    Job Site Set Up

    2. H2

    3. Emergency Alarm (air horn) spotted next to SCBA.

    S monitor spotted down wind and in view of crew. Monitor set for continuous monitoring.

    4. Upon signs of significant release (10 PPM) alarm will sound on monitor - all Emergency Action Steps

    crew members evacuate upwind or crosswind of work area to gathering area.

    5. One man, assigned by name during pre-job brief, dons SCBA and returns to equipment and shuts it down, closes valves and isolates system.

    6. One man, assigned by name during pre-job brief, sounds alarm (air horn) and notified plant representative. Maintains communication with crew man shutting down equipment.

    7. Remaining crew members will evacuate area as per plant evacuation procedures.

    8. After equipment shut down and plant notification, remaining crew members evacuate as directed by plant personnel.

    1. Emergency first aid/CPA provided to any injured personnel as required.

    Post Incident

    2. No employee re-enters work area until authorized to do so by Plant Safety Personnel.

    3. Crew leader-supervisor immediately notifies division management of situation.

    Supervisor Crew Crew



    Crew Crew

    Hydrogen Sulfide Scrubbing Procedure Hydrogen Sulfide, H2

    S, is a highly toxic, highly flammable gas with the odor of rotten eggs. If the gas is released into open air, a public nuisance or severe air pollution problem may result. Personnel in the immediate vicinity may be overcome. Provisions should be made to dispose of the gas by venting to a flare. Hydrogen Sulfide gas is flammable and can be readily introduced into a regular flare system.

    Another method of disposal is to bubble the gas through a scrubber system containing Caustic (Sodium Hydroxide). By this manner, the gas is converted to Sodium Sulfide and retained in the caustic solution. The main concern would be that sufficient scrubber capacity is made available. For every 100 pounds of Ferrous Sulfide to be dissolved, 91 pounds of Caustic is required. It is suggested that the Caustic strength should even be doubled, to ensure no possible air pollution hazards. As much depth as possible should be provided for the Caustic solution to allow more contact time with the gases as they bubble through the solution. For every 87.85 pounds of Ferrous Sulfide dissolved there will be 34 pounds of Hydrogen Sulfide gas released. Also, 98 pounds of Sulfuric Acid will be consumed and 151.85 pounds of Ferrous Sulfate will be formed. For every 73 pounds of HCl, or 98 pounds of Sulfuric Acid, added to the cleaning solution, a maximum of 34 pounds of H2S will be generated. For every 34 pounds of H2

    S generated, 80 pounds of Caustic will be needed to scrub the gas.

    Minimum Requirements 100 pounds of FeS will require 27.33 gal of 20 oBe Hydrochloric Acid or require 7.58 gal of 96 % by weight Sulfuric Acid and produce 38.7 pounds of Hydrogen Sulfide gas and will require 14.3 gal of 50 % by weight Caustic to scrub the released H2

    S gas.


    It is always necessary to add 25 % excess Caustic to the scrubbing unit. This ensures that enough Caustic will be available to capture the H2S gases being released. The following precautions can be observed to minimize the possibility of a H2

    S release:

    1. Prior to injection of the Acid, determine the maximum quantity of H2S that can formed and the amount of NaOH necessary to effectively scrub the H2For every 100 gallons of 22

    S. o baume HCl used in the dissolution of FeS, 142 gallons

    of 25 % wt. NaOH is required to absorb the H2

    S gases that would be released. 177 gallons of caustic with 25 % excess.



    For every 100 gallons of 96 % by wt. H2SO4 used in the dissolution of FeS, 473 gallons of 25 % wt. NaOH is required to absorb the H2

    S gases that would be released. 592 gallons of caustic with 25 % excess.

    2. The system should be leak tested before injection of any chemicals. A leak of H2

    S gas could be deadly. Also, if a pressure surge vessel is used to direct gases into the scrubbing system, it should be tested to ensure that it is leak free.

    3. Initial injection of the Acid should be into COLD WATER. Each 20 oF increase of temperature doubles the reaction rate. As the acid dissolves the Sulfide scale, heat is produced also. The temperature should be monitored.

    4. The concentration of Acid should be increased slowly. Do not increase the acid

    concentration until the gases released from the previous injection have subsided. This will provide the operator with the ability to maintain control of the reaction.

    5. As the H2

    S evolution subsides, both the acid strength and temperature can be increased gradually.

    6. The lines directing the gases to the caustic scrubber should have CHECK VALVES installed to prevent any caustic from being drawn back into the acid cleaning solution. Such a vacuum can happen due to cooling of the system or an inadequately vented system during the solvent drain.

    7. NEVER dispose the Caustic scrubber solution to an area that contains low pH

    solvents. This will liberate H2

    S and could prove disastrous.

    8. Do not add acid into the caustic scrubber too fast when neutralizing. Too much acid can generate enough H2S gas to rupture a hose or seal. Oxidation of the scrubber solution with Potassium Permanganate or Hydrogen Peroxide prior to neutralization will prevent the release of H2

    S when the scrubber solution is neutralized.

    In addition to the precautions, which should be observed to prevent a release of H2

    S, there are safety precautions which we must be aware of and observe to minimize possible injury in the event of such a release.

    1. All personnel working under conditions which may result in an H2S release must be trained in the specific hazards of H2

    S safety.

    2. Wind socks should be installed in the vicinity of the cleaning to assist personnel in their decisions for an escape route.

    3. Filled and operable escape packs (SCOTT) must be on location and strategically

    placed to assist rescue attempts in the event of injury. Never attempt to rescue a downed victim without supplied air breathing equipment.

    4. An air horn will be needed for alerting other personnel in the case of an H2

    S release.



    Oxidizing Agents To Reduce Hydrogen Sulfides A scrubber solution containing both caustic and an oxidizer will be the best solution for capturing and containing H2S gases. The Caustic solution will capture the gas and form Sodium Sulfide. This compound can be transformed back into H2S just by adding acid. To eliminate this unwanted reaction, an oxidizer can be added to the Caustic solution. This will react with the Sodium Sulfide and form Sodium Sulfate (Na2SO4


    Note that this compound will not create H2

    S when acidified.

    Na2S + 4 H2O2 -----> Na2SO4 + 4 H2


    Potassium Permanganate can be used to oxidize a caustic solution containing sulfides. The point of oxidation is noticeable as the purple solution will turn to a greenish-blue color that is common in Potassium Permanganate solutions. A brown color represents a spent solution of Permanganate. Most other oxidizers will not have a noticeable color change at the point of oxidation. All oxidizers will create significant amounts of heat upon reaction.

    3 Na2S + 8 KMnO4 -----> 3 Na2SO4 + 8 MnO

    Sodium Potassium Sodium Manganese 2

    Sulfite Permanganate Sulfate Dioxide

    100 pounds of FeS will create 38.7 pounds (or 452 ft3) of H2

    153.4 pounds of Hydrogen Peroxide

    S which will require (for oxidation):

    159.8 pounds of Potassium Permanganate






    Other Facts About H21. Extremely toxic, ranking second to Hydrogen Cyanide.

    S Gas

    2. Colorless gas with odor of rotten eggs. 3. Heavier than air and will accumulate in low lying areas. 4. Forms explosive mixture with air between concentrations of 4.3 % and 46 % by

    volume. 5. Auto-ignition temperature of 500 oF; Cigarette burns at 1,400 o

    6. Corrosive to plastics, elastomers, and body tissue. F.


    S gas is notable at low concentrations by smell. This should not be used as a log-term indicator as the gas will paralyze the sense of smell. In some instances, a person may only smell the rotten egg scent for a second or two, then cease to smell the odor. It could still be present but the person can no longer detect it. This person should move cross wind to a safe area. The odor is detectable at 0.13 pp.


    Employees most take time to read this program before handling any hazardous chemical. This program contains information on safe handling and storage of chemicals, recommended personal protective equipment, and health/physical hazards of many specific chemicals and chemical groups. Additional information is available on the material safety data sheets.