The OSK™ FKM Replacement O-Ring for Graco® 246354 is a direct-fit spool valve O-Ring engineered for the Graco® Fusion® Air Purge (AP) spray gun. Made from 75A durometer fluorocarbon (FKM), this O-Ring replaces the Graco® original used in the spool valve and air trigger assembly of Fusion® AP and Fusion® ProConnect (PC) spray foam guns.
Get your Graco® Fusion® gun back in service without overpaying for OEM parts. The O-Ring Store LLC supplies this OSK™ 246354 replacement in the same FKM compound and profile as the Graco® original, delivering reliable sealing on the spool valve that controls clean-off air to the mix chamber. Spray foam contractors and insulation maintenance teams rely on this seal to prevent air leaks at the trigger mechanism, maintain proper air purge function, and keep jobsite downtime to a minimum. The FKM material handles the chemical exposure and heat that spray polyurethane foam (SPF) and polyurea coating applications demand.
Operating Temperature
-15 to +400F (-26 to +204C)
Material and Performance Details
This OSK™ 246354 replacement O-Ring is molded from fluorocarbon (FKM), a premium elastomer recognized for broad chemical resistance and high-temperature stability. At 75A Shore A durometer, FKM delivers excellent compression set resistance at elevated temperatures and maintains a reliable seal through repeated thermal cycling. FKM is the standard material for Graco® Fusion® spray gun O-Rings due to the aggressive chemical environment inside the gun during polyurethane and polyurea spraying operations.
- Excellent resistance to: petroleum oils, aromatic fuels, chlorinated solvents, mineral acids, hydraulic fluids (petroleum-based), silicone fluids, fuel (gasoline, diesel, JP-8), dilute acids
- Limited capability with: steam, hot water (above 300F), low-molecular-weight esters, some ketones
- Not compatible with: ketones (MEK, acetone), amines, anhydrous ammonia, ethylene oxide, low-molecular-weight organic acids
Applications and Use Cases
The Graco® 246354 spool valve O-Ring is a wear item on the Graco® Fusion® Air Purge (AP) spray gun, one of the most widely used applicators in the spray polyurethane foam insulation and polyurea coating industries. The spool valve controls the flow of clean-off air that purges residual material from the mix chamber after each trigger release. When this O-Ring wears or degrades, air leaks develop at the trigger mechanism, leading to inconsistent purge cycles, cross-contamination between the A-side and B-side chemical streams, and potential gun lock-ups on the jobsite. This O-Ring is also used in the Graco® Fusion® ProConnect (PC) gun in the same spool valve position. Spray foam contractors performing residential and commercial insulation, roofing, cold storage, and tank lining work replace this seal during routine gun maintenance, typically during weekly or bi-weekly rebuilds. The 246354 is included in the Graco® Fusion® AP rebuild O-Ring kit (Graco® part 246355) as a quantity of five.
Key Specifications
- Material: Fluorocarbon (FKM)
- Durometer: 75 Shore A
- Temperature Range: -15 to +400F (-26 to +204C)
- OEM Replacement For: Graco® 246354
Why Buy from The O-Ring Store LLC
The O-Ring Store LLC is an ISO 9001:2015 certified distributor with USA-based stock for fast delivery. Most in-stock items ship the same day. We offer full lot traceability and documentation on request, plus expert technical support from staff with decades of sealing experience in the spray foam industry. Every order is verified through our Olypsys® scan-based quality system before it ships. We stock multiple grades of the 246354 replacement, including Commercial, OEM, Extreme, and FFKM, so you can match the right material to how you maintain your gun. Competitive pricing with no compromise on quality. We make getting O-Rings easy!
Frequently Asked Questions
Q: Is the OSK™ 246354 the same fit as the original Graco® 246354 O-Ring? A: Yes. The OSK™ OEM Grade 246354 matches the original Graco® O-Ring in profile and material. It installs in the same spool valve position on the Graco® Fusion® AP and Fusion® PC spray guns without modification.
Q: What material is the OSK™ OEM Grade 246354 replacement made from? A: The OEM Grade version is made from fluorocarbon (FKM) at 75 Shore A durometer. FKM is the same base compound family Graco® specifies for this position because of its resistance to the isocyanate and polyol chemicals used in spray foam applications.
Q: How often should I replace the 246354 spool valve O-Ring on my Graco® Fusion® AP gun? A: Graco® recommends a full gun rebuild, including the spool valve O-Ring, on a weekly basis for crews spraying daily. If you notice air leaking from the trigger area, inconsistent purge cycles, or difficulty pulling the trigger, inspect and replace the 246354 O-Ring immediately to avoid downtime.
