7/31/2019 New Tower Start-Up

1/2

Chemical Solution, Inc. Technical Data Sheet

CLEANING, PASSIVATION and STARTUP of NEW COOLING SYSTEMS

Prior to hydraulic testing or putting a new system into service, it must

be cleaned to remove oil, grease, new pipe mill scale, silts and organicdebris, and general rust accumulations. It is then chemically

passivated to inhibit corrosion of the various metallurgies involved.

Since the system may also contain microbiological contamination,

disinfection should be provided prior to allowing any aerosol

emissions from any wet-type heat rejection device (WTHRD), e.g.,

cooling towers, and evaporative condensers. Accordingly, the

cleaning and disinfection procedures presented herein also incorporate

the procedural concepts and disinfection guidelines for system start-up

as endorsed by The Centers for Disease Control and Prevention

(CDC) and as published in the "1987 Wisconsin Guidelines" entitled,

Control of Legionella in Cooling Towers, Summary Guidelines.

NACE publication item number 21027 may serve as an additional

reference for the initial conditioning of cooling water equipment.

NOTES: This procedure cannot nor can any of the CDC/Wisconsin

cleaning/disinfection procedures guarantee elimination of Legionella

bacteria or any other pathogen from cooling systems. Workers should

be instructed and trained in protective procedures to minimize

exposure to biological and chemical agents which may occur during

system cleaning.

Contaminants referenced above and a poor passivation program can

cause a wide variety of operating problems. Oil can aggravate

corrosion by hindering the ability of chemical corrosion inhibitors to

function and by contributing to the formation of corrosion cells. Siltdeposits and organic debris can retard heat transfer, restrict water

flow, initiate formation of corrosion cells, and enhance the corrosive

actions at existing corrosion cells. This leads to additional localized

corrosion and subsequent leaks. These deposits also hinder the

protective action of corrosion inhibitors, and can provide a "protective

home" for many types of micro-organisms including corrosive ones

such as the acid producing, sulfate reducing bacteria.

Open recirculating water systems are typically constructed of mild

steel, zinc-galvanized steel, copper, and brass metallurgies. Some may

contain stainless steel, admiralty, and/or aluminum metallurgies.

Thus, highly alkaline "boil out" procedures typically prescribed by

boiler manufacturer's operating manuals for "all steel" boilers areNOT acceptable.

Cleaning procedures based on strong, inhibited mineral acids can be

risky for some metallurgies, are hazardous to handle, and are much

more difficult to dispose of. The cleaning and passivation procedures

employed in systems containing a zinc-galvanized WTHRD is most

important to aid initial formation of a proper zinc oxide barrier. After

start-up and concentration of

makeup water impurities, system operation at moderately alkaline

conditions (pH 8 - 9) and with water containing highconcentrations of carbonate alkalinity could lead to formation of

zinc carbonate (i.e. "White Rust") if the zinc galvanize is not

initially passivated. The combination of cleaning and passivation

chemical formulations and procedures described below function

at pH neutral to very mildly alkaline conditions, contain

phosphates to aid initial passivation of the zinc, and have been

proven quite successful.

Initial Flushing of Newly Constructed Systems

New systems must be first filled with water to check for leaks and

flushed to remove construction debris and loose deposits. Dead

ends and low velocity areas should be flushed/drained until allsediment has been removed. The system volume (water holding

capacity) should be established to effectively estimate cleaning

chemical and treatment requirements. An alternate to any initial

calculation/estimation of system capacity from design data is to

perform a traced ion study during the initial system filling and

circulation just prior to flushing. Once flushed, the system should

not be allowed to sit idle for more than a day or two before all

observed leaks are repaired and the chemical cleaning,

passivation, and disinfection program is performed.

Additional tasks prior to circulating any water over the cooling

tower or other WTHRD should include:

Turn off (lock out) the tower fans to avoid formation and

emission of any contaminated aerosols; i.e. water mist. Close

nearby building air intakes; say intakes within 30 meters

(100 feet) of the cooling tower. This step is also very

important prior to conducting any high dosage chemical

cleaning, passivation, and disinfection in order to protect

building occupants from high levels of chlorine or bromine

gas and other biologic agents that would otherwise be

aerosolized during this process.

Remove all loose construction materials. Inspect the tower

fill, drift eliminators, and fan belts. Repair or properly install

as deemed necessary.

Ascertain that the makeup water fill line is positioned so that

the chemically treated circulating water cannot "backup" or

siphon into the water supply lines. Make sure there are no

system cross connections with the potable water supply.

(continued on other side)

Cleaning of Newly Constructed Systems

ALL RIGHTS RESERVED. Do not duplicate this document by any method without prior

written permission from Chemical Solution, Inc.

7/31/2019 New Tower Start-Up

2/2

CLEANING, PASSIVATION and STARTUP of NEW COOLING SYSTEMS (continued)

Additional preparations after system flushing, repair of any leaks

encountered, and estimation of system holding capacity include:

Shut down the system's bleedoff conductivity controller and close

bleedoff valve.

Verify that the chemically treated system bleedoff water will

comply with proper regulatory agency discharge requirements;

i.e. an EPA/State NPDES permit for discharges to a surfacestream or, if required, a local POTW permit regulating discharges

into a public sanitary sewer system.

Add the cleaning, passivation, and disinfection chemical formulations

in accordance with the specific product selections and dosage

instructions provided by the water treatment specialist serving the

facility. A two step process is outlined in the following paragraphs.

Circulate this initial cleaning-passivation solution for 24 to 48 hours at

a cleaning temperature of 50oF to 100

oF. The warmer temperatures

will be more effective and permit more rapid cleaning. After the

initial cleaning solutions are flushed from the system, the subsequent

passivation chemical program should ideally be circulated for an

additional one to two weeks to optimize the passivation process.During this period of time the system may be operated at low heat

load and low cycles. Microbiocides should be added in accordance

with the program selected for the on-going treatment program. The

chemical formulations required for this two step process are generally

described in the following paragraphs.

Initial Cleaning and Passivation

SERIES 1960 Formulations are concentrated mixtures of

chelating agents, sequestrants, and metal passivators with

polymeric dispersants, an azole yellow metal inhibitor, and

surfactants. These products are mildly alkaline as necessary to

maintain product stability. If the system being cleaned containszinc galvanize, the pH of the circulating water needs to be

adjusted downward to pH neutral or very slightly alkaline; pH of

7.0 to 7.5. This can be best accomplished by using an organic

acid-based formulation. This mild organic acid serves to lower

the pH to the desired range and has mild cleaning properties to

aid removal of metal oxides such as mill scale and rust.

NOTE: The cleaners and surfactant contained in the SERIES 1960

Formulations are NOT designed for systems heavily fouled with oil.

An alternate cleaner or supplemental addition of a SERIES 1335 or

1340 Formulation may be required. The water treatment specialist

serving the facility should be consulted.

FORMULA 3218 and FORMULA 3214 are two different

organic acid-based formulations available to accomplish the

above mentioned objectives. FORMULA 3218 is a concentrated

liquid also containing a phosphonate sequestrant. FORMULA

3214 is a powdered formulation that would be most cost-effective

for large systems.

ALL RIGHTS RESERVED. Do not duplicate this document by any method without prior written

FORMULAs DL-1542 through DL-1547 are glutaraldehyde

based microbiocides. These non-oxidizing-type biocides are

preferred for disinfection of new systems as they would not

adversely effect the new, un-passivated metallurgies as would

high dosages of chlorine. Once diluted in the system's waters,

they are compatible with the above referenced

cleaning/passivation formulations.

Oxidizing chlorine based disinfectants such as sodium

hypochlorite liquid (FORMULA 1582) or chlorinated

isocyanurate powder (FORMULA 1588-G) are both good

sources of chlorine that can be used prudently with the above

referenced products. Maintenance of chlorine residuals at 1-

2 ppm free chlorine should be quite sufficient to compliment

the above cleaning-passivation program without necessarily

hindering initial system passivation.

NOTE: The CDC/Wisconsin guidelines for start-up of existing

systems and emergency disinfection of systems containing

objectionable concentrations of Legionella specify chlorine

dosages of 25 and 50 ppm and maintenance of 10 ppm for 24

hours.

After circulating the above solution for 24 to 48 hours, drain and

flush the system by procedures described above and in

accordance with specific system characteristics learned during

initial system flushing. IMMEDIATELY refill the system with

clean water and add the final passivation and disinfection

formulations specified by the water treatment specialist and as

generally described below.

Final Passivation and Disinfection

SERIES 1930 Formulations are concentrated mixtures of

molybdate, complex polyphosphates, orthophosphate, and azole

yellow metal-based corrosion inhibitors ideal for passivation of

cooling systems. The formulations also contain phosphonates and

multi-functional polymer dispersants to aid product performance

during initial one to two weeks of system operation provided the

system only experiences moderate heat loads and is operated atlow cycles to aid in maintaining operation at pH 7.0 to 7.5.

Feed microbiocides as deemed necessary and specified by the

water treatment specialist serving the facility. This program

could utilize the same products referenced above and selected for

the initial cleaning process.

The SERIES 1930 passivation program may not require system

flushing. At start-up, simply initiate the automated bleedoff valve

to regulate desired cycles of concentration. The SERIES 1930

passivation formulation will be removed by normal system

bleedoff and replaced by the specific corrosion/scale inhibitor and

dispersant formulation specified by the facility's water treatmentspecialist for use during the on-going treatment program

permission from Chemical Solution, Inc.