4" Grooved Rigid Coupling – Ductile Iron, UL/FM Approved

🔩 4" Grooved Rigid Coupling – UL/FM Approved for Fire Protection & Commercial Piping

This 4-inch Grooved Rigid Coupling is designed for a strong, non-flexing connection between grooved-end pipes in fire sprinkler systems, HVAC water loops, and mechanical installations. Its rigid design ensures no axial or angular deflection, maintaining pipe alignment under pressure and mechanical stress.

Built from ASTM A536 ductile iron and coated with corrosion-resistant orange enamel or zinc galvanization, it features a Grade E EPDM gasket pre-lubricated for fast and secure sealing. Fully UL Listed and FM Approved, this coupling meets the highest performance and safety standards in the industry.

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⚙️ Key Features

• Size: 4" nominal pipe size (NPS)
• Pipe OD Compatibility: 4.500" (Schedule 40 steel pipe)
• Material: Ductile iron housing (ASTM A536)
• Gasket: Grade E EPDM, pre-lubricated
• Finish: Orange enamel or galvanized
• Design: Rigid – zero movement, holds pipe alignment
• Certifications: UL Listed, FM Approved, ANSI/AWWA C606 compliant

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📐 Specifications

• Working Pressure: Up to 500 PSI
• Temperature Range: -30°F to 230°F (EPDM)
• Installation Torque: Typically 80–100 ft-lbs

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🧱 Why Ductile Iron?

Ductile iron is used in all high-performance rigid couplings due to its unmatched strength and longevity:

• Pressure-rated strength: Withstands high system loads
• Impact resistance: Less prone to cracking under mechanical stress
• Coated for corrosion resistance: Performs in damp, outdoor, and indoor environments

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💡 Common Applications

• Fire sprinkler mains and risers
• Chilled and condenser water piping
• Commercial HVAC and mechanical piping
• Industrial process water systems

Heavy-duty performance. UL/FM compliant. Ready for any jobsite.

❓ Frequently Asked Questions

1) What pipe size is this made for?
It fits 4" Schedule 40 steel pipe with a 4.500" outside diameter.

2) Is this UL/FM certified?
Yes — this coupling is both UL Listed and FM Approved for use in critical systems like fire protection and mechanical loops.

3) What's included?
The housing, EPDM gasket, and bolts are all included — ready to install out of the box.

4) Is this a flexible or rigid coupling?
Rigid. It’s designed to hold pipe sections in fixed alignment with no deflection or movement.