Check valves operate on differential pressure principles:  

• Cracking Pressure: Minimum 0.14 MPa required to open (adjustable for low-flow systems)  
• Closing Mechanism: Spring-assisted closure completes in <0.8 seconds to prevent water hammer  
• Flow Efficiency: 90° swing disc design reduces turbulence by 37% compared to traditional 45° models

3 Critical Factors When Specifying Industrial Check Valves  

A. Pressure-Temperature Ratings  

Class	Max Pressure (MPa)	Temperature Range
150#	1.96	-29°C ~ 200°C
300#	5.08	-29°C ~ 260°C

B. Seal Compatibility  

• EPDM: pH 2-12 chemicals, 120°C max  
• PTFE: Universal chemical resistance, 204°C rated  

C. End Connection Optimization

• Flanged: ASME B16.5 for >DN50 pipelines  
• Threaded: NPT/BSPP standards for compact systems

Maintenance Protocols to Prevent Valve Failure  

Annual Inspection Checklist:  

1. Disc movement test (should rotate freely without >0.5mm axial play)  

2. Seal replacement if compression set exceeds 15%  

3. Bolt torque verification (ASME PCC-1 standards):  

Bolt Size	Torque (Nm)
M16	110 ±10%
M20	220 ±10%

Pro Tip: Install pressure gauges upstream/downstream to detect >10% pressure drop indicating wear.