Protecting Idle Systems

© 2015 Eastern Technologies, Inc. www.go2eti.com

VpCI Technology Overview

Protecting Idle Systems Lay-up and Construction

Presented By: Gary Reggiani - Eastern Technologies Inc.


Vapor-phase Corrosion Inhibitors (VpCI)

•  Innovative, environmentally friendly •  Three phase corrosion (VpCI) inhibitors •  Effective inhibitors for preconstruction, preoperation, and

idle operation


How VpCI Technology Works

•  VpCI products contain inhibitors which sublime or emit into the air space. In order to ensure all metal surfaces are protected, enough VpCI product must be added to provide a sufficient concentration of gaseous VpCI molecules in the air space. This vaporizing ability enables these VpCIs to protect without direct application to the metal surface.

•  A close up view illustrates how the gaseous VpCI molecules adsorb onto the the metal surface. The VpCI molecules in the air dissolve in any moisture that may be present, and form a barrier that will effectively protect metal surfaces for up to two years.


Metal Surface

Molecules of VpCI in gaseous phase

- + + + + + + +

+ + +

- - - - - - - - -

-

2

1

Anode Cathode



Molecule Surface Binding Energy

Water ≈ 43 (Kcal/mol)

VpCI - A ≈ 150 (Kcal/mol), >3 times water

VpCI - B ≈ 800 (Kcal/mol), almost 20 times water

VpCI molecules are water soluble and possess more binding energy to metal surfaces than that of water dipoles. This allows the VpCI molecules to displace water at the surface, establishing an anchor point that prevents

corrosive species from reaching the metal surface.



•  How do you monitor? √  Performance: corrosion coupons/ probes/spools, start-up water

quality √  Dosage: tracer residual for the powdered products

•  Is it toxic? √  Recent aquatic toxicity data completed for seawater species

•  Is it compatible with commonly used materials? √  See summary table, VpCIs compatibility evaluated for common MOC

•  Will VpCIs cause/aggravate MB fouling potential? √  Laboratory MB work suggests “No” √  Testing done using Pseudomonas Aeruginosa

Application Issues


Chemical LD 50 (mg/kg-rat)

Table Salt (Sodium Chloride)

Food Preservative/Cor.Inh (Sodium Nitrite)

85

Cortec VpCI 5000

Toxicity


Material Comment

Elastomer Immersion Test: tested at 23 degree C & 50 degree C

Natural Rubber Buna Rubber EPDM Rubber

Compatible Compatible Compatible

Metals & Alloys Immersion Tests:

Carbon Steel Stainless Steel Copper Alloy Cast Steel

Galvanized Steel

Compatible Compatible Compatible Compatible Compatible

Certain products are designed for steel only systems and can be neutral or even aggressive to copper.

Plastics & Miscellaneous Materials (based on use experience):

PVC Teflon

Compatible Compatible

Compatibility


•  Boiler & Cooling Lay-up -  Many successful applications -  Dose rates well established -  Good, consistent performance

Water Treatment Applications


General Experience/Comment

•  Best fix – root cause fix •  Most systems not set-up to do

and high cost to get set-up

•  Performance with this approach is fair to poor

•  Many feel that it is difficult to justify cost vs. performance

•  Concern for fouling and creating an MB problem

•  Simple approach with proven success and no negative effects

Cooling System Lay-up Alternatives

Lay-up Options

•  By-pass recirculation -  isolate tower & exchanger and circulate

water

•  Use conventional inhibitor approach -  lay-up dry or partially flooded

•  Use hydrocarbon or filming technology -  best to lay-up dry

•  Use VpCI technology -  lay-up dry or partially flooded


Cooling Lay-up Case History

•  Two HVAC cooling systems historically winterized

•  Facility had startup problems with both systems

•  One system laid-up with Cooling Loop Gator for 5+ months – (1) Cooling Loop Gator/1000 gallons volume

•  Plant tried conventional passivation technology with minimal success

•  Plant started up the VpCI treated cooling system without chip scale and bulk water iron oxide

•  Plant started up the untreated cooling system and had problems with chip scale (causing flooding of the distribution deck) and high bulk water iron


Lay-up Options

•  Lay-up Wet with sulfite & caustic -  isolate boiler and circulate water

•  Lay-up Dry with desiccant -  isolate boiler, N2 blanket optional

•  Use VpCI technology -  lay-up dry or partially flooded


•  Effective for seasonal or short term lay-ups •  Important to keep boiler flooded •  Important to maintain circulation •  Routine testing required & re-treatment often

necessary

•  Hassle to install and remove desiccant •  Slow start-up of boiler •  Little tolerance for moisture •  Nitrogen blanket can be safety issue and

costly

•  Simple approach for short and long term lay-up

•  Both wet and dry lay-up options •  Quick start-up of boiler •  Tolerant of moisture •  Used in low and high pressure boilers

Boiler System Lay-up Alternatives


Boiler Lay-up Case History

•  Two boilers historically online •  Facility decided to operate only one boiler

to improve fuel efficiency •  Firetube boiler laid-up with Boiler Lizard

for 12 months – (1) Boiler Lizard/1000 Gals Vol.

•  Plant chose VpCI technology instead of desiccant to have quick startup

•  Plant chose VpCI technology instead of sulfite due to historical poor results

•  Picture to right documents successful lay-up with Boiler Lizard



•  Difficult to stop corrosion once it starts •  Cleanup cost is high and may not

practical

•  Performance is generally fair to poor •  Requires contact with metal surfaces

•  Concern for fouling and potential MB •  Not environmentally friendly

•  Simple approach with proven success and no negative effects

•  Contact with surfaces not required – functions in liquid phase, vapor/liquid interface and vapor phase

Hydrotesting Inhibitor Alternatives

Lay-up Options

•  Do not treat during construction phase -  Clean system after construction is

complete

•  Use conventional inhibitor approach -  Drain water or leave flooded

•  Use hydrocarbon filming technology

-  Best to drain, but could be flooded

•  Use VpCI technology -  Drain water or leave flooded


Hydrotesting Case History

•  Used in new construction site with specification that all water added to the system must have inhibitor.

•  VpCI-649 was used at a dose rate of 500 PPM to 2000 PPM.

•  Proper dose can easily be applied by flow proportioned feeding into the fill water supply.

•  System started with no water quality problems and system was free of corrosion.


Other Applications

•  Fire Water Systems -  Similar to hydrotesting application

•  Pre-installation of equipment -  Similar to equipment lay-up

•  Electronic Panels -  Special foam VpCI emitters


Product Selection

•  S-69: liquid VpCI, No Dispersant, distribution in water phase -  dosed at 2000+ PPM (1.5 – 2.0 gals per 1000 gals of volume) -  Requires pumped circulation

•  VCI-649: liquid VpCI, W/ Dispersant, distribution in water phase -  dosed at 2000+ PPM (1.5 – 2.0 gals per 1000 gals of volume) -  Requires pumped circulation

•  S-69P: powder VpCI, No Dispersant, distribution in water phase -  dosed at 1000+ PPM (8.5-10.0 lbs per 1000 gals of volume) -  Requires premixing of powder and pumped circulation

•  Cooling Gator: powder VpCI, water-soluble bag, distribution in water phase -  dosed at 1000+ PPM (8.5 – 10.0 lbs per 1000 gals of volume) -  Requires premixing of powder and pumped circulation

•  VCI-337: liquid VpCI, No Dispersant, fog/atomized into air space -  dosed at 1.5 – 2.0 oz per ft3 (5-gal pail per 100’ of 24” diam., SCH40 pipe) -  Requires method of atomization, such as compressor

•  NOTE: a lower dosage can be used when applying for short durations, such as, before chemical cleaning, draining and refilling the system.


Water Distribution Application

Application Using VpCI Liquid: 1.  Add biocide* as needed to disinfect the system.

2.  Add/pump VpCI liquid directly to MU (for mixing) in proportion to MU flow

3.  Circulate the treated water solution if possible

4.  Drain the system or leave fully or partially flooded -  If water is left stagnant, additional disinfectant may be necessary. -  Use corrosion coupons (exposed to same conditions) to monitor results

5.  Close and secure openings (does not require a hermetic seal)

Application Using VpCI Powder: 1.  Add biocide as needed to disinfect the system same as above.

2.  Preferably pre-mix VpCI powder and then add/pump into system.

3.  Duplicate steps 3-5 same as above.

* Use a biocide that 1) is compatible with VpCI and 2) functions to mitigate slime and anaerobic bacteria forms.


Fogging Application

Application Process for Large Volumes:

1.  Using water select nozzle size to provide a fog with consistency similar to that produced by an aerosol can such as hair spray.

2.  Place VCI 337 into tank (or place suction hose into tank holding VCI 337)

3.  Position nozzle so that the stream does not make direct contact with a surface less than four feet from the nozzle tip (if the stream impinges on a flat surface before it has had time to fully atomize, it will knock the fluid out of the air stream and create a continuous stream flowing down the wall surface).

4.  Apply at a rate of 1.5 to 2.0 oz/ft3 (greater than 24-months protection) -  If possible, create a slight vacuum across (inlet to outlet) system to be protected. -  If fogging into a closed volume with no cross flow, apply in short burst due to

backpressure build up. 5.  Close and secure openings (does not require a hermetic seal)

NOTE: + Power washers are flooded suction type pumps and require that source be higher than the pump inlet or that a secondary positive displacement pump be used to provide flow to the power washer pump inlet.

+ Nozzle orifice size (hole diameter): 4.0 (.052”/1.32mm) - 6.0 (.062”/1.57mm)

Documents

Protecting Idle Systems