L278-CS-300-ANSI Class 300 Cast Steel Swing Check Valve

L278-CS-300 Series

ANSI Class 300 Cast Steel Swing Check Valve

• Flanged ends, bolted cover, WCB body & cover, 13Cr/HF trim.
• Flange dimensions: ANSI B16.5
• Face-to-Face dimensions: ANSI B16.10
• Testing: API 598
• Design: API 600

Class 300 cast steel swing check valves provide automatic non-return service for higher-pressure applications — power plant feedwater lines, refinery and oil/gas process service, high-pressure steam condensate, and pump-discharge service in industrial process plants where the system operating pressure exceeds the Class 150 working-pressure envelope. The Class 300 rating supports approximately 740 psi at 100°F per ANSI B16.34, derating with rising temperature according to standard pressure-temperature curves.

The swing-disc design provides automatic backflow prevention without external actuators — forward flow lifts the disc clear of the flow path, while gravity and any reverse pressure seat the disc against the body seat to stop reverse flow. WCB cast steel body and cover construction combined with 13Cr stainless trim handles moderate-temperature, non-corrosive process media reliably. Bolted-cover construction allows in-line servicing of the disc, hinge pin, and seat without cutting out the valve. Flange dimensions conform to ANSI B16.5 Class 300 raised-face, face-to-face dimensions follow ANSI B16.10, and API 600 design / API 598 testing standards ensure dimensional and quality consistency.