Study of Carbon Steel Pipes 2013

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STUDY OFCARBON STEEL

PIPE

By:

Deepak Ramchandani

SDB-90, Adipur

Taluka-Gandhidham

District-Kachchh, Gujarat


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CARBON STEEL PIPES

A STUDY

BY

Deepak RamchandaniSDB-90, Adipur, Taluka Gandhidham,

District Kachchh, Gujarat-India

M-+919426321521

JULY-2013


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Preamble:

This study is conducted as a technocrat and this has

nothing to do about promotion and demotion of any typeof pipe and also nothing to do for selection of pipematerial.

This study is not compared with other variety of pipeline.

This is for private circulation for fresh pipe line engineersand shall not be considered as any authentic documentfor any purpose.

The suggestions for improvement are invited from allreaders.

It is just the effort to study the carbon steel pipe as it isnow being widely used for large size diameters.

The study shall not be related to my personal experienceof me with different type of pipelines.

It is just a study made for reference purpose to thelearners.

This shall not be treated as document from the expert,but I myself is learner and had made effort to learn whilewriting the same.

Deepak Ramchandani


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STUDY OF CARBON STEEL PIPES

Definition of pipe:-

A pipe is a tubular section or hollow cylinder, usually but notnecessarily of circular cross-section, used mainly to conveysubstances which can flow liquids and gases (fluids), slurries,powders, masses of small solids. It can also be used for structuralapplications; hollow pipe is far stiffer per unit weight than solidmembers.

In common usage the words pipe and tube are usuallyinterchangeable, but in industry and engineering, the terms areuniquely defined. Depending on the applicable standard to which it ismanufactured, pipe is generally specified by a nominal diameter witha constant outside diameter (OD) and a schedule that defines thethickness. Tube is most often specified by the OD and wall thickness,but may be specified by any two of OD, inside diameter (ID), and wallthickness. Pipe is generally manufactured to one of severalinternational and national industrial standards.[1] While similarstandards exist for specific industry application tubing, tube is oftenmade to custom sizes and a broader range of diameters andtolerances. Many industrial and government standards exist for the

production of pipe and tubing. The term "tube" is also commonlyapplied to non-cylindrical sections, i.e., square or rectangular tubing.In general, "pipe" is the more common term in most of the world,whereas "tube" is more widely used in the United States .

Both "pipe" and "tube" imply a level of rigidity and permanence,whereas a hose (or hosepipe) is usually portable and flexible. Pipeassemblies are almost always constructed with the use of fittingssuch as elbows, tees, and so on, while tube may be formed or bentinto custom configurations. For materials that are inflexible, cannot beformed, or where construction is governed by codes or standards,tube assemblies are also constructed with the use of tube fittings.


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Types of Pipe Material

In the past, many types of material have been used in conveyingwater from one point to another. Masonry and wood were probably

the first materials used. Plastics are the newest, and are now beingused quite extensively. At present, water mains are made of a varietyof materials, summarized in the chart below.

Material Advantages Disadvantages PrimaryUse

Coated?

cast iron no longermanufactured;deteriorates in somesoils

large, oldsystems

yes

ductile iron strong, ductile deteriorates in somesoils

largesystems

yes

steel inexpensive wall thickness mustbe carefullyconsidered

raw watermains

yes

concrete inexpensive raw watermains andindustrialsystems

no

pre-stressedconcrete

inexpensive raw watermains andindustrialsystems

no

asbestos cement brittle; no longermanufactured

replacedcast iron; inold systems

no

PVC inexpensive gasoline from soil canpass into pipe


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non-rigid plastic requires special heatfusion joining tools;inorganic chemicalsin soil weaken pipe

service linesin watersystemsand mainlines in gas

systems

no

copper service lines no

galvanized iron corrodes; producesdiscoloured water;has a short life;deteriorates in somesoils

no

Steel piping may be used in water transmission mains due to thecheap initial construction cost of the system. However, care must betaken in the design of the wall thickness of the steel pipe for theparticular systems that exist. Steel pipes are more commonly usedfor raw water mains.

Even though most public water supplies are treated where necessaryfor corrosion control, all three types of metal pipes described abovecan be corroded by acidic water. For this reason, these pipes are

usually lined to protect the metal against corrosion.Carbon steel pipes can all be weakened in just a few years when laidin aggressive soil. To prevent this type of damage, the soil should betested before laying the pipes in the ground. If necessary, the pipesshall be externally coated.

Metallic pipes

Metallic pipes are commonly made from steel or iron; the finish andmetal chemistry are peculiar to the use, fit and form. Typically metallicpiping is made of steel or iron, such as unfinished, black (lacquer)steel, carbon steel, stainless steel or galvanized steel, and ductileiron.


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Manufacture

There are three processes for metallic pipe manufacture. Centrifugalcasting of hot alloyed metal is one of the most prominent

process.[further explanation needed] Ductile iron pipes are generallymanufactured in such a fashion. Seamless (SMLS) pipe is formed bydrawing a solid billet over a piercing rod to create the hollow shell.Historically seamless pipe was regarded as withstanding pressurebetter than other types, and was often more easily available thanwelded pipe. Advances since the 1970s in materials, process controland non-destructive testing allow correctly specified welded pipe toreplace seamless in many applications. Welded (also ElectricResistance Welded ("ERW"), and Electric Fusion Welded ("EFW"))pipe is formed by rolling plate and welding the seam. The weld flashcan be removed from the outside or inside surfaces using a scarfingblade. The weld zone can also be heat treated to make the seam lessvisible. Welded pipe often has tighter dimensional tolerances thanseamless, and can be cheaper if manufactured in the samequantities. Large-diameter pipe (25 centimeters (10 in) or greater)may be ERW, EFW or Submerged Arc Welded ("SAW") pipe.

Standards

Pressure piping is generally pipe that must carry pressures greaterthan 10 to 25 atmospheres, although definitions vary. To ensure safeoperation of the system, the manufacture, storage, welding, testing,etc. of pressure piping must meet stringent quality standards .

Manufacturing standards for pipes commonly require a test of chemical composition and a series of mechanical strength tests foreach heat of pipe. A heat of pipe is all forged from the same castingot, and therefore had the same chemical composition. Mechanicaltests may be associated to a lot of pipe, which would be all from thesame heat and have been through the same heat treatmentprocesses. The manufacturer performs these tests and reports thecomposition in a mill traceability report and the mechanical tests in amaterial test report, both of which are referred to by the acronymMTR. Material with these associated test reports is called traceable.For critical applications, third party verification of these tests may be


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required; in this case an independent lab will produce a certifiedmaterial test report(CMTR), and the material will be called certified.

Some widely used pipe standards are:

IS:3589 , Indian standard The API range - now ISO 3183. Used for oil and gas pipe line ASME SA106 Grade B (Seamless carbon steel pipe for high

temperature service) ASTM A312 (Seamless and welded austenitic stainless steel

pipe)

Installation

Pipe installation is often more expensive and a variety of specializedtools, techniques, and parts have been developed to assist this. Pipeis usually delivered to a customer or jobsite as either "sticks" orlengths of pipe (typically 12 mt, called single random length). Thepipe and pipe spools are delivered to a warehouse on a largecommercial/industrial job and they may be held indoors or in agridded lay down yard. The pipe or pipe spool is retrieved, staged,rigged, and then lifted into place. On large process jobs the lift ismade using cranes and hoist and other material lifts. They aretypically, temporarily, supported in the steel structure using beamclamps, straps, and small hoists until the Pipe Supports are attachedor otherwise secured .

After the pipe is installed it will be tested for leaks. Before testing itmay need to be cleaned by blowing air or steam or flushing with aliquid.

Pipe supports

Pipes are usually either supported from below or hung from above(but may also be supported from the side), using devices called pipesupports. Supports may be as simple as a pipe "shoe" which is akinto a half of an I-beam welded to the bottom of the pipe; they may be"hung" using a clevis, or with trapeze type of devices called pipehangers. Pipe supports of any kind may incorporate springs,snubbers, dampers, or combinations of these devices to compensate


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for thermal expansion, or to provide vibration isolation, shock control,or reduced vibration excitation of the pipe due to earthquake motion.Some dampers are simply fluid dashpots, but other dampers may beactive hydraulic devices that have sophisticated systems that act todampen peak displacements due to externally imposed vibrations ormechanical shocks. The undesired motions may be process derived(such as in a fluidized bed reactor) or from a natural phenomenonsuch as an earthquake (design basis event or DBE).

Pipe hanger assembles are usually attached with pipe clamps.Possible exposure to high temperatures and heavy loads should beincluded when specifying which clamps are needed

Joining

Pipes are commonly joined by welding.Process piping is usually joined by welding using a TIG or MIG process. The most commonprocess pipe joint is the butt weld. The ends of pipe to be weldedmust have a certain weld preparation called an End Weld Prep(EWP) which is typically at an angle of 37.5 degrees to accommodatethe filler weld metal.

Design Period

Manual stipulate design period, For some components it may bemodified depending on its useful life, facility for carrying outextensions when required and interest rate so that expenditure farahead of utility is avoided. Land for future extension should beacquired in beginning itself. Project components may be designed tomeet the requirements of the following design period.

Sl.No. Data Source Designperiod inyears

1 Storage by dams 502 Infiltration Works 303 Pumping

i. Pump house (civil works) 30


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ii. Electric motors and pumps 154 Water treatment units 155 Pipe connection to several treatment units and

other small appurtenances30

6 Raw water and clear water conveying mains 307 Clear water reservoirs at the head works,balancing tanks and service reservoirs (overheador ground level)

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8 Distribution system 30

Important:-The pipe line shall be of such material that shall lastat least 30 years

Corrosion resistance of some metals:-

The below mentioned list shows the corrosion resistivity of varioustype of pipe material. The list is extensive only mentioned for purposeof knowledge, but the main concern in this list is chlorinated water, ascarbon steel pipes are also being used in the conveyance lines aftertreatment plant.

Corrosion Resistance 1)Good 2) Be Careful 3) NotUseable

CarbonSteel

CastIron

302 and304

StainlessSteel

316Stainless

Steel

416Stainless

Steel

Acetaldehyde 1 1 1 1 1

Acetic acid, air free 3 3 2 2 3Acetic acid, aerated 3 3 1 1 3Acetic acid, vapors 3 3 1 1 3

Acetone 1 1 1 1 1Acetylene 1 1 1 1 1Alcohols 1 1 1 1


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CarbonSteel

CastIron

302 and304

StainlessSteel

316Stainless

Steel

416Stainless

Steel

Aluminum Sulfate 3 3 1 1 3Ammonia 1 1 1 1 1

Ammonium chloride 3 3 2 2 3Ammonium Nitrate 1 3 1 1 3

Ammonium Phosphate 3 3 1 1 2Ammonium Sulfate 3 3 2 1 3Ammonium Sulfite 3 3 1 1 2

Aniline 3 3 1 1 3Asphalt 1 1 1 1 1

Benzene (benzol) 1 1 1 1 1Benzoic acid 3 3 1 1 1

Boric acid 3 3 1 1 2Butane 1 1 1 1 1

Calcium Chloride (alkaline) 2 2 3 2 3Calcium hypochlorite 3 3 2 2 3

Carbolic acid 2 2 1 1Carbon dioxide, dry 1 1 1 1 1Carbon dioxide, wet 3 3 1 1 1

Carbon disulfide 1 1 1 1 2Carbon tetrachloride 2 2 2 2 3

Carbonic acid 3 3 2 2 1Chlorine gas 1 1 2 2 3

Chlorine gas, wet 3 3 3 3 3Chlorine, liquid 3 3 3 3 3Chromic acid 3 3 3 2 3

Citric acid 3 3 2 1 2Coke oven gas 1 1 1 1 1

Copper sulfate 3 3 2 2 1Cottonseed oil 1 1 1 1 1

Creosote 1 1 1 1 1Ethane 1 1 1 1 1Ether 2 2 1 1 1

Ethyl chloride 3 3 1 1 2


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CarbonSteel

CastIron

302 and304

StainlessSteel

316Stainless

Steel

416Stainless

Steel

Ethylene 1 1 1 1 1Ethylene glycol 1 1 1 1 1Ferric chloride 3 3 3 3 3Formaldehyde 2 2 1 1 1

Formic acid 3 2 2 3Freon wet 2 2 2 1 naFreon dry 2 2 1 1 naFurfural 1 1 1 1 2

Gasoline 1 1 1 1 1Glucose 1 1 1 1 1

Hydrochloric acid, aerated 3 3 3 3 3Hydrochloric acid, air free 3 3 3 3 3Hydrofluoric acid, aerated 2 3 3 2 3Hydrofluoric acid, air free 1 3 3 2 3

Hydrogen 1 1 1 1 1Hydrogen peroxide 1 1 1 2

Hydrogen sulfide, liquid 3 3 1 1 3Magnesium Hydroxide 1 1 1 1 1

Mercury 1 1 1 1 1Methanol 1 1 1 1 1

Methyl ethyl ketone 1 1 1 1 1Natural gas 1 1 1 1 1Nitric acid 3 3 1 2 3Oleic acid 3 3 1 1 1

Oxalic acid 3 3 2 2 2Oxygen 1 1 1 1 1

Petroleum oils 1 1 1 1 1

Phosphoric acid, aerated 3 3 1 1 3Phosphoric acid, air free 3 3 1 1 3Phosphoric acid vapors 3 3 2 2 3

Picric acid 3 3 1 1 2Potassium chloride 2 2 1 1 3

Potassium hydroxide 2 2 1 1 2


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CarbonSteel

CastIron

302 and304

StainlessSteel

316Stainless

Steel

416Stainless

Steel

Propane 1 1 1 1 1Rosin 2 2 1 1 1

Silver Nitrate 3 3 1 1 2Sodium acetate 1 1 2 1 1

Sodium carbonate 1 1 1 1 2Sodium chloride 3 3 2 2 2

Sodium chromate 1 1 1 1 1Sodium hydroxide 1 1 1 1 2

Sodium hypochlorite 3 3 3 3 3Sodium thiosulfate 3 3 1 1 2Stannous chloride 2 2 3 1 3

Stearic acid 1 3 1 1 2Sulfate liquor 1 1 1 1

Sulfur 1 1 1 1 1Sulfur dioxide, dry 1 1 1 1 2Sulfur trioxide, dry 1 1 1 1 2

Sulfuric acid, aerated 3 3 3 3 3Sulfuric acid, air free 3 3 3 3 3

Sulfurous acid 3 3 2 2 3 Tar 1 1 1 1 1

Trichloroethylene 2 2 2 1 2 Turpentine 2 2 1 1 1

Vinegar 3 3 1 1 3Water, steam boiler feeding system 2 3 1 1 2

Water, distilled 1 1 1 1 2Water, sea 2 2 2 2 3

Zinc chloride 3 3 3 3 3

Zinc sulfate 3 3 1 1 2

From the above it is observed that corrosion resistivity of carbon steel against gases is good and against acids and l iquidchlorine is very poor.


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Effect of corrosion on carbon steel and cast iron due tochlorine


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Effect of corrosion on mild steel due to chlorine

Corrosion causes gradual decay and deterioration of pipes, bothinternally and externally. It can reduce the life of a pipe by eatingaway at the wall thickness. Under certain conditions, the time for thedecay to cause the pipe to fail is as short as five years. Corrosion canalso result in encrustation inside the pipe, reducing the carryingcapacity of the pipe to a point that it has to be replaced to provide theflow needed

EXTERNAL CORROSION

The best indication of whether or not the outside of a pipe will corrodeis the soil resistivity, which can be measured by one of several typesof meters. The four-point type is used most often because it canmeasure the average resistivity of the soil down to the pipeline. Somewater systems use soil resistivity to determine the type of pipe toinstall. If the soils resistivity is greater than 5,000 ohms per centimeter(cm), serious corrosion is unlikely; ductile iron or steel pipe could beused in these situations. If the resistivity is less than 500 ohms/cm,however, the potential for corrosion is greater. In these cases, non-metallic pipe such as asbestos cement or PVC should be used.


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Ductile iron, if used in soil with low resistivity, should be wrapped toprevent contact with the soil.

INTERNAL CORROSION

PROPERTIES OF WATER AFFECTING CORROSION

The property of the water passing through the piping system greatlyaffects the corrosion rate of the material. These effects can beexplained in terms of electrochemical theory. The water propertiesthat affect corrosion include the concentration of dissolved oxygen,the temperature, the velocity of the water, the chlorine residual, andthe concentration of the chloride ions.

Dissolved Oxygen

The concentration of dissolved oxygen is one of the most importantfactors influencing the rate of corrosion for all metals. At ordinarytemperatures, the absence of dissolved oxygen will greatly slowcorrosion of ferrous metals. Oxygen is a direct participant in thecorrosion reaction, acting as a cathode-accepting electron.

The level of oxygen concentration increases as the rate of theelectron transport increases. As a result, the rate of corrosion formost metals increases with any increase of dissolved oxygen.

Temperature

Corrosion represents a particular group of chemical reactions. Therate of any particular chemical reaction will increase with a rise in thetemperature and decrease with a drop in the temperature.

Changes in temperature can influence the chemical composition andphysical properties of the water, the character of any scales formedon the metal, and the nature of the metal itself. Temperature affectsthe solubility of many gases, such as oxygen, that are important tothe rate of corrosion. With any increase in temperature, an increaseof corrosion activity is expected.


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Velocity

The velocity of the water in the piping system is important to the rateof corrosion. The critical velocity is considered to be greater than1.2mt per second. This type of corrosion is called erosion corrosionand involves the removal of dissolved metal ions. It is typicallycharacterized by grooves, gullies, or waves on the inside of the pipe,especially near points of turbulence. Tees and elbows are often thefirst to fail when excessive velocities occur.

Chlorine

Chlorine is an effective oxidation chemical; therefore, it is assumedthat it will take the place of oxygen in any corrosion processes. Free

chlorine residuals tend to cause more corrosion than combinedresiduals .

Conclusion :-In case of ch lorine liquid all the type of metals arenot useable : If carbon steel pipe used for treated water in whichthere is chlorine contain than the metal is highly susceptible tothe corrosion , hence in small pipes where inside protection on

jo ints is not poss ible such pipes must not be used. In larger pipes where internal coating on pipes is possible shall only beused, pipes shall also be externally coated with impervious coatand cathode protection is desirable to increase the life of pipe.

Cathode Protection: Remedy for corrosion

The reactions involved in corrosion are electrochemical in nature.With external corrosion, the current paths are not continued to theinside surfaces of the pipe; therefore, galvanic corrosion electrolysisis relatively more important and cathodic protection is usuallypractical.

Electrolysis is the decomposition of a substance by the passage of anexterior source of direct electrical current (D. C.). When a D. C.current flows from a metal to soil, most metals are corroded.


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Alternating current (A. C.) electrolysis will also corrode metals, but thepossible effect is considered to be only one percent of what would becaused by the same flow of direct current from the pipe and causes itto flow from the anode to the cathode. This method of protection hasalso been used with some success on water piping.

The natural-gas industry has had great success with this method,which involves attaching cathodes (negatively charged metals) oranodes (positively charged metals) to the pipe. These charged metalswill corrode instead of the pipe. The anodes or cathodes introduce acurrent to the pipe. This changes the current flow

ADDITIONAL DATA COLLECTION FROM FIELD SURVEY FOR ARRANGEMENT OFEVALUATION OF CATHODE PROTECTION IS REQUIRED:

Route and types of foreign service/ pipelines in and around,running parallel or crossing the right of way.

Diameter, wall thickness, pressure, soil cover etc. of the foreignpipeline.

Foreign pipeline coating details. Details of existing cathodic protection systems protecting the

services including rating and location of grounds bed, teststation locations and connections schemes etc. Where pipelineis likely to pass close to any existing ground bed, necessary

anode-bed potential gradient survey shall be carried out. Interference remedial measures existing on foreign pipelines/

services/ shall be collected from the owner of the foreignpipeline/ services.

Graphical representation of existing structure/ pipe to soilpotential records, Transformer Rectifier Unit/ CP Power sourcevoltage/ current readings.

Possibilities of integration / isolation of the proposed pipelineCP System with foreign pipeline / structure CP System, which

may involve negotiation with Owners of foreign services. Crossings or parallel running of any H.T. AC/ DC overhead linewith in approximately 25 mtr from ROW along with details of voltage rating, fault level etc.

Voltage rating, phases and sheathing details of parallel runningor crossing of under ground cables with ROW.


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Crossing and parallel running of electrified and non-electrifiedrailway tracks along with details of operating voltage and type(AC/ DC) as well as abandoned tracks near ROW havingelectrical continuity with track in use.

Information on existing and proposed DC / AC power sourcesand system such as electric substations / earthing stations,fabrication yards with electric welding in the vicinity of the entireright of way.

Major river / canal crossings. Major cased crossings. Any other relevant information that may be needed in designing

and implementing of proper cathode protection scheme for theproposed pipeline.

SOIL RESISTIVITY SURVEY:-The provision in the specification of GAIL

Unless otherwise specified the soil resistivity measurements shall becarried out at intervals of approximately 500 mtr. along the ROW.Where soil resistivity is less than 100 ohm mtr and two successivereadings differ by more than 2:1 then additional soil resistivityreadings in between the two locations shall be taken.

To carryout the soil resistivity measurement Wenners 4 pin methodor approved equal shall be used. The depth of resistivitymeasurement shall be around the burial depth of the pipeline or 1.5mtr approximately. At locations where multi layer soil with largevariation in resistivity/ corrosiveness is expected and/ or locationsspecifically advised by Owner or his representative resistivitymeasurements at additional depth of up to 2.5 mtr (approx.) or moreshall be taken. In general the resistivity of soil which shall be

surrounding the pipe shall be measured. Hence the depth of measurement/ electrode spacing may vary depending on topographyand strata at the area. In general, electrode spacing, shall beapproximately equal to 1.5 times the depth of the pipelines .


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TESTS ON SOIL SAMPLES

Soil/ water samples shall be collected along the right of way foranalysis. Samples shall be collected on an average at one locationper every 10 km along right of way with minimum at two locations.Exact locations shall be decided at site depending on the type of soil,soil resistivity and in consultation with Owner or his representative.

The soil samples shall be collected at 1 mtr and 2 mtr depth at eachlocation.

The collected soil/ water samples shall be analysed to determinepresence and percentage of corrosive compounds including moisturecontent, oxygen activity and pH value.

HR COILS WITH BELOW MENTIONED ADDATIVES TO BE USED TOIMPROVE THE CORROSION RESISTANCE OF THE MATERIAL:

Chromium: Best for corrosion resistance

Among the alloying elements of steel, chromium forms part of thosewhich best promote harden ability. In fact, its effect on steel is quitesimilar to that of manganese in the way that it enhances muchhardness penetration. When being present in reasonable quantities,

chromium contributes much in reducing the quenching speed. In fact,such a slow quenching is achieved thereby enabling steel to be oil orair hardened. Chromium is also recommended when there is goodwear resistant steel of appreciable toughness required. Chromium isalso very popular as alloying element as it is quite efficient inrendering steel resistant to staining and corrosion. Moreover,chromium forms carbides that improve edge-holding capacity. Steel,rich in chromium have also high temperature strength and they arequite resistant to high-pressure Hydrogenation.

Molybdenum: For corrosion resistance

Molybdenum is an alloying element which is seldom used on its own.In fact, molybdenum is used in combination with other alloyingelements. This alloying element increases the hardness penetrationof steel and also contributes in slowing down the critical quenching


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speed. Molybdenum proves to be useful also for increasing tensilestrength of steel. Furthermore, it prevents temper brittleness and itfavors the formation of a fine grain structure. It is good also tomention that molybdenum forms carbides readily and it thus improvesthe cutting properties in high-speed steels. Hence, it can be said thatmolybdenum helps much in increasing machinability .

Nitrogen: For corrosion resistanceBeing a residual element, nitrogen is present, in small quantities, inall steels. In fact, the nitrogen will normally combine with otherelements in the steel (like Aluminum, for example) to form hardnitrides. Thus nitrogen increases hardness, tensile and yield strength,

but still, there are certain drawbacks related to nitrogen as it causes aconsiderable decrease in toughness and in ductibility of steel.

Types of manufacturing process

LSAW

LSAW has large diameter and wall thickness, resistance to highpressure, resistance to low temperature and strong corrosioncharacteristics. When constructing high strength and toughness, highquality oil and gas pipeline over long distances, what is required ismostly large caliber straight double submerged arc welding joints.According to the API standard provisions, LSAW is the onlydesignated for tube type when passing through the cold region,submarine, the urban population dense area of 2 kinds, 1 region inthe large oil and gas pipeline .

SSAW Spiral welded steel pipe(SSAW) is mainly used in oil and gastransmission pipe line, and its specification is expressed as outsidediameter * wall thickness .according to the external structure, it isclassified single welding and double welding. Technically, the welded


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steel pipe should ensure that hydrostatic test, weld tensile strengthand the cold bending property can comply with the regulations.

Design Criteria for Metallic Pipe : The code uses three different approaches to design, as follows :

1. It provides for the use of dimensionally standardizedcomponents at their published pressure-temperature ratings.

2. It provides design formulas and maximum stresses.3. It prohibits the use of materials, components, or assembly

methods in certain conditions .

IS:3589 :- Indian standard code for manufacturing of carbon steel pipes:-

This standard was originally published in year 1966, revised in 1981,1991 and year 2001 .

1. In this revision diameter and thickness of the pipes are now as

per international standards.2. Table for chemical composition of metal properties is included.

3. For coatings some suggestions are given and details code are

yet to be published

This standard is limited to diameter ( OD) 2540 mm

In Indian standard code design of pipe thickness for internal pressure

is given where as for handling stresses and ring stability standards of American manual could be adopted.

For handling stability minimum thickness shall be D/288 in mm.

For buried pipe under vacuum and internal pressure minimumthickness of D/158 in mm may be adopted.


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For deciding thickness for height of soil cover following chart could beconsidered.

SOME SUGGESTIONS

Coating thickness of 3 lpe along with relevant code is requiredto be mentioned in SOR

2 mm for pipe up to 250 mm 2 2 mm for pipe from 250-500 mm 2.5 mm for pipe from 500-800 mm Above 800 mm diameter -3.0 mm Coating for joint thickness shall also be specified.

For internal coating, coating thickness of epoxy paint of 406microns to be specified in SOR with applicable code AWWA C-210-03


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Steel grade not specified in the SOR , grade Fe-410 to bespecified

Thickness in lower diameters is having ranges and field officersare at liberty to take any thickness , calculation of thickness arerarely asked in technical committee In larger diametersthickness is kept fixed, even if as per design thickness is lessor more field officers follow the SOR provisions only withoutderiving exact thickness requirement.

Norms for thickness of MS pipes shall be finalized by technicalcommittee and only provision of that thickness to be made inSOR.

This SOR is used for other organization which rely on GWSSB,hence a note should be mentioned in SOR regarding thickness to be calculated as per actual requirement of theuser

Standard code for cement mortor lining and gunniting are alsonot mentioned, even thickness of lining and gunniting is notmentioned.

Manual of steel pipe of America to be studied in depth and tobe made applicable as per requirement.

Carbon steel pipes in aggressive soil without any imperviouscoating shall not be used. Cement coating is not imperviouscoating as the cement have tendency to absolve water.

Carbon steel pipes of the size in which it is not possible for ahuman to enter and apply coating at joints shall not be used ,as the pipe lines laid in the department of small sizes are leftuncoated at internal joints and advanced techniques of mechanical methods were never used. Human can enter inminimum 900 mm diameter pipe that too it is possible to coat 5-6 joints from the open end and a continuous process shall beadopted for inside joint coating along with pipe laying.


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Carbon steel pipes when used for treated water are mostsusceptible to corrosion due to residual chlorine in water , insuch types only impervious internal coating is suggestive, and

inside joint coating is compulsory required It is suggestive to conduct a survey of performance of pipes laid

under the department in various soil conditions and for treatedand raw water pipes.

References:Source internet

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Study of Carbon Steel Pipes 2013

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