Graco 256771 Solvent Resistant O-Rings - Aftermarket | Bedford 55-3121

Keep your Graco Fusion CS spray gun performing reliably with this six-pack of solvent-resistant O-rings. These rings seal the check-valve housing against chemical bypass, ensuring consistent pattern control and smooth trigger action. Designed for plural-component environments, this aftermarket kit replaces Graco 256771 with Bedford 55-3121, offering durable elastomeric material that resists swelling and deformation when exposed to common cleaning solvents used in foam and polyurea applications.

AftermarketSolvent-Resistant CompoundPlural-Component Duty

Why Choose These O-Rings

  • Engineered for resistance to acetone, MEK, and other flush solvents used with spray-foam rigs.
  • Maintains tight sealing under dynamic pressure cycles to prevent air or material leaks.
  • Includes six pieces for quick service replacements and on-site maintenance.

Color: Black solvent-resistant elastomer; supplied in six-ring pack.

Typical Compatibility

  • Graco Fusion CS plural-component spray gun - check-valve housing assembly.
  • Compatible across Fusion CS short and long-barrel variants used in SPF and polyurea systems.
  • Used on plural-component rigs equipped with Fusion CS, ClearShot, or similar guns.

Confirm placement using your Fusion CS Illustrated Parts List to ensure correct groove location.

What This Product Fits

  • Graco Fusion CS Spray Gun (standard and long barrel) - O-rings for check-valve housing.
  • Fusion CS models used on plural-component proportioners including Reactor E-10, E-20, E-30, H-25, H-40, H-50, H-XP2 and H-XP3.
  • Applicable to spray-foam, polyurea, and hybrid material applications requiring Fusion CS assemblies.

Verified against Graco Fusion CS parts documentation and Bedford cross-reference confirming 55-3121 as replacement for OEM 256771.

Technical Specifications

Aftermarket Bedford 55-3121
OEM Graco 256771
FitsFusion CS spray gun check-valve housing
TypeSolvent-resistant O-ring kit (6 pieces)
MaterialHigh-performance solvent-resistant elastomer
FunctionPrevents air or fluid leakage in the check-valve housing assembly
PressureRated within Fusion CS working-pressure limits per Graco manual
BrandBedford Precision Parts (Aftermarket)

For best results, follow Graco service manual torque specifications and assembly sequence.

Installation Notes

  1. Depressurize system and engage trigger lock before service.
  2. Disassemble the check-valve housing and remove old O-rings.
  3. Clean grooves and metal surfaces; inspect for nicks or wear.
  4. Lightly lubricate new O-rings with approved grease and seat evenly.
  5. Reassemble and test spray pattern to confirm seal integrity.

Tip: Replace the entire set at once to ensure uniform compression and performance.

When to Rebuild / Replace

  • Leakage from check-valve housing or inconsistent spray pattern.
  • Flattened or swollen O-rings after solvent exposure.
  • Air ingress causing pattern flutter or pressure loss.
  • Visible cuts or abrasion on seal surfaces.

Bedford vs OEM Comparison

FeatureBedford Aftermarket (55-3121)OEM (Graco)
Fit & LocationFusion CS check-valve housing O-ringsFactory O-rings for same assembly
Chemical ResistanceHigh solvent resistance for acetone/MEKOEM graded elastomer
AvailabilityIf in stock, ships from Bedford Precision Parts in Bedford Hill, New York.Ships via Graco distribution
ValueCost-efficient alternativeOEM program

FAQs

Yes, Bedford 55-3121 is listed as the aftermarket equivalent for Graco 256771 solvent-resistant O-rings used in Fusion CS guns.
They fit the Fusion CS spray gun and all associated plural-component rigs like Reactor E-10, E-20, E-30, H-25, H-40, H-50, H-XP2 and H-XP3.
Each kit contains six O-rings to service the check-valve housing and keep spares available for maintenance.
No special tools are needed; use standard hand tools and approved assembly grease while avoiding O-ring twisting or pinching.
Yes, they are compatible with plural-component systems processing polyurea or foam materials where Fusion CS guns are specified.