Waterborne Fogging Corrosion Inhibitor – 5 Gallon Pail (Cortec® VpCI®-337)

Description

VpCI®-337 is a ready-to-use waterborne corrosion inhibitor for fogging void spaces: double walls, complex cavities, pipe runs, tanks, turbines, the inside of a crate. It leaves a thin, soft, self-healing film that does not affect paintability, conductivity or appearance, and there is nothing to degrease or strip when the equipment goes back to work. At the 0.5 to 1 oz/ft³ fogging rate a 5-gallon pail treats roughly 640 to 1,280 cubic feet of void, enough for a bank of pipe spools, a heat exchanger shell or several crates.

Fogging means spraying the liquid as a fine mist so the droplets stay suspended and diffuse through the air space; VpCI-337 vapors travel up to 100 feet through piping, including bends, so a sealed system is protected without anyone reaching inside it. Protection lasts up to two years as long as water ingress is prevented. Cortec positions it as the replacement for nitrogen blankets and dehumidification in plant lay-up, and for boilers, HRSGs and turbines it has a second advantage: within about 24 hours of restart the inhibitor decomposes to carbon dioxide and nitrogen oxides, with no explosive hazard, so nothing has to be flushed. In the Cortec Product Consultation Guide VpCI-337 is rated 2, inside storage, on carbon steel, stainless steel, cast iron, aluminum alloys, galvanized steel, copper, brass and solder; it is a multi-metal product for enclosed and indoor use, not an exterior coating. A Winterized grade with a −44 °C freeze point is available for cold-climate work.

Typical applications

• Pipe, spool and modules
• Void space protection
• Edge spray for coils and sheet stock
• Double wall void spaces
• Fogging of tanks, containers, packages and enclosures
• Boilers and HRSG fire and water sides during outages
• Gas and steam turbine internals, valves and generator housings in lay-up
• Heat exchangers before shipment or storage
• Skid-mounted equipment and modules sealed for transport
• Void spaces in crates and shipping containers

How to apply VpCI-337

1. Surface preparation. SSPC-SP-1: free of grease, oil, corrosion, dirt, dust and mill scale, and completely dry.
2. Mix and test. Mix VpCI-337 thoroughly. Test the spray so the liquid is fully suspended: if the ground under the gun wets quickly the droplets are too large, so adjust the equipment. No dilution.
3. Seal the enclosure. Cover all but two openings, one low for the fog inlet and one high for exhaust (or the reverse). Use pipe caps, CorrCaps or MilCorr shrink film to close the others.
4. Fog. Dose at 0.5 to 1 fl oz per cubic foot of void (0.5 to 1 liter per cubic meter). Fog through the inlet until mist appears at the exhaust, cap the exhaust, continue to the full 0.5 to 1 oz/ft³ dose, then seal the inlet. A small pressure vent may stay open but keep it minimal. For complex piping, fog one section at a time; a fan or vacuum at the exhaust helps the fog travel, though the vapors move up to 100 feet on their own.
5. Equipment. Graco Delta Spray or LT series guns, or the Graco Finex #289258; for large enclosures a gun can be fixed in place and left running until the dose is reached.
6. Drying and protection. There is no cure step; the mist settles into a thin self-healing film and the vapor phase fills the space. Protection lasts up to two years if water is kept out through seals and vents.
7. Long lay-ups. For more than two years, install corrosion coupons at the entry port, inspect them every one to two years and re-dose with VpCI-337 as needed.
8. Return to service. No removal is needed. In fired equipment the residue decomposes to CO₂ and NOₓ within roughly 24 hours of operation.
9. Storage. Water-based: keep from freezing, or specify VpCI-337 Winterized.

Compatibility

Cortec’s elastomer chart lists VpCI-337 as compatible at full strength with nitrile, HNBR, EPDM, natural rubber, Viton, PTFE, polyurethane, polypropylene, nylon, PET, acetal, fiberglass, Aflas and Kalrez, and at 20 % with PVC. Turbine OEM testing found no negative effect on gas turbine, steam turbine or HRSG alloys, no intergranular attack or stress-corrosion cracking and no effect on thermal barrier coatings, and an SCR catalyst manufacturer found no impact on its catalyst. See the full oil and elastomer compatibility charts.

Where it fits in the Cortec line

VpCI-337 is the liquid fogging product. EcoAir VpCI-337 puts the same chemistry in a 13 oz compressed-air can with a locking release valve for crates and small enclosures. Where a powder is preferred, VmCI-307 and VpCI-309 fog at 0.5 oz/ft³ and VpCI-308 pouches drop into voids at one per 35 ft³. For oil systems in the same lay-up, M-531 goes into the lube oil and VpCI-322 is fogged into drained tanks. For a wet or dry coating on exterior surfaces use VpCI-377. Browse the full Cortec VpCI line.

Field notes

A 53 MW Alaska utility plant laid up a steam turbine, boiler and piping for up to three years. All openings were sealed except one port top and one bottom; a blower on the far port created a draft, VpCI-337 was fogged at 1 oz per ft³ (0.9 L per m³) of void until mist exited the second port, then the ports were sealed and labeled VpCI Protected. The vapor travelled about 100 ft through piping with bends. (Cortec Case History #500)

For 14 years a UK power station’s boilers rusted during annual outages and blew rust out of the stacks at restart. A contractor sprayed VpCI-337 into the top and bottom of the boilers and onto the walls and tube banks across seven levels; the plant had its first rust-free restart in 14 years and now does it every outage. (Cortec Case History #649)

A Houston air-cooler manufacturer found its nitrogen-purged bundles leaked as the steel blinds contracted in temperature swings. It switched to fogging VpCI-337 into the bundles and sealing with PVC bumper gaskets, with flange faces de-rusted with VpCI-423 gel, degreased with VpCI-414 and sprayed with CorShield VpCI-368. No hermetic seal is needed. (Cortec Case History #823)

Watch: Fogging VpCI-337 into equipment

Video by Cortec Corporation.

Specifications

Film	Thin, soft, self-healing
Application	Ready to use — no dilution
Fogging dosage	0.5–1.0 fl oz per cubic foot (0.5–1.0 L/m³) of enclosed space
Vapor travel	Up to 100 ft through piping including bends
Protection period	Up to 2 years sealed; coupons and re-dose for longer
Removal	No removal needed; easy to remove if required. No degreasing or stripping — protected products are ready to use
Compatibility	Does not affect paintability, conductivity or appearance
pH	7.2–9.0 (neat)
Weight per gallon	8.7–8.9 lb (1.04–1.06 kg/L)
Flash point	>200 °F (93 °C)
Biodegradability	87% biodegradation in 28 days (VpCI-337)
Metals	Carbon steel, stainless steel, cast iron, aluminum, galvanized steel, copper, brass, solder
Consultation guide rating	2 – inside storage
Surface preparation	SSPC-SP-1, completely dry
Equipment	Graco Delta Spray or LT series; Graco Finex #289258
Restart behavior	Decomposes to CO₂ and NOₓ within about 24 hours in fired equipment; no explosive hazard
Elastomers	Compatible at 100 % with nitrile, HNBR, EPDM, natural rubber, Viton, PTFE, polyurethane, polypropylene, nylon, PET, acetal, fiberglass, Aflas, Kalrez; PVC at 20 %
Storage	40–120 °F (4–49 °C); Winterized grade −40 to 120 °F; shelf life 24 months
Variant	VpCI-337 Winterized (water and propylene glycol carrier) freezes at −47 °F (−44 °C); VpCI-337 GE for sodium- and sulfur-sensitive systems
Size	5 Gallon Pail
Shipping weight	47.5 lb (21.5 kg)
Availability	In stock
Cortec product number	12000033

Solvent Recycling Systems is an authorized Cortec® distributor. See the full Cortec VpCI line, browse the VpCI product selection guide, or contact us for volume pricing and lead times.