Replacing a Spring-Loaded Safety Valve?
Use code, pressure, capacity, temperature, and materials—not brand—to verify a replacement.
Before you continue — confirm these conditions apply
- Valve type: Spring-loaded (not pilot-operated)
- Code: ASME Section VIII
- Set pressure: ≤ 350 psig (air/gas/liquid) OR ≤ 250 psig (steam)
- Temperature: -320°F to 406°F
- Connections: Threaded (NPT, BSPT, BSPP), Tri-Clamp
- Flanges: Not Available
If any item above does not match your existing valve, a different 740-family configuration or series may be required. Recommended alternatives are shown below.
Note: This guide covers the most common threaded, spring-loaded replacement configurations within the 740-series family. Flanged, stainless, high-pressure, and specialty variants are available and routed below when applicable.
Non-Negotiable Limits (740 Series)
| Code | ASME Section VIII |
|---|---|
| Max Pressure (Air/Gas/Liquid) | 350 psig |
| Max Pressure (Steam) | 250 psig |
| Temperature Range | -320°F to 406°F |
| Orifice Range | D through JL (1/2" to 3" inlet) |
| Connections | Threaded (NPT, BSPT, BSPP), Tri-Clamp |
| Flanges | Not Available |
| Body Material | Brass/Bronze |
| Certifications | ASME VIII, CE, CRN |
Good Replacement Candidate If:
- Spring-loaded safety valve
- ASME Section VIII application
- Pressure and temperature within series limits
- Threaded or Tri-Clamp connections
- General industrial overpressure protection
- Standard brass/bronze construction acceptable
Not a Replacement If:
- Steam above 250 psig → 741, 742, 743
- Air/liquid above 350 psig → 741, 742, 743
- Requires flanged connections → 741, 742, 743
- Requires stainless body → 743
- High temperature (above 406°F) → 742, 743
- ASME Section I / boiler service → 560/563 series
- Pilot-operated valve → Contact Us
Before You Configure: Nameplate Data Required - What You Need From the Existing Valve
- ASME code stamp Look for "UV" symbol on nameplate
- Set pressure Must match new valve exactly
- Relieving capacity Or orifice letter (D, E, F, G, H, J)
- Service medium Air/gas, steam, or liquid
- Inlet size Include thread type (NPT, BSPT, BSPP)
- Outlet size
- Connection type Threaded or Tri-Clamp
- Body/trim material Check compatibility with process
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Replacement suitability must be verified against all applicable codes and system requirements. SafetyControlValves.com provides configuration tools to assist in valve selection.