SPIRAX SARCO · SAFETY VALVES
Spirax Sarco SV74 Carbon Steel Safety Valve – ASME Certified Pressure Relief
Spirax Sarco SV74 carbon steel safety valve, ASME I & VIII certified for steam boilers, pressure vessels & process systems. Available at PC Engineering
Overview
The Spirax Sarco SV74 is a carbon steel safety valve designed and manufactured in conformance with ASME Boiler and Pressure Vessel Code Sections I and VIII. It provides reliable overpressure protection for power boilers, unfired pressure vessels, and steam systems where code-stamped valves are mandatory.
The SV74 features a robust carbon steel body with stainless steel trim for corrosion resistance and extended service life. The open bonnet design with easing lever allows for manual testing, while flanged connections (ASME Class 300 inlet, Class 150 outlet) ensure secure integration into existing piping systems.
This safety valve is approved by the National Board of Boiler and Pressure Vessel Inspectors and complies with EU Pressure Equipment Directive and UK Pressure Equipment (Safety) Regulations. Seat tightness meets ASME/API STD 527-1992 standards.
Key Features
- ASME Section I and VIII certified with National Board approval
- Carbon steel body (SA 216 Gr. WCB) with stainless steel trim
- Orifice sizes from 'F' to 'R' for wide capacity range
- Flanged connections: ASME Class 300 RF inlet, Class 150 RF outlet
- Open bonnet with easing lever for manual lift testing
- Adjustable blowdown with upper and lower adjusting rings
- Derated coefficient of discharge: 0.955 for steam and air/gas
- CE marked for EU/UK compliance when required
Specifications
| Parameter | Value |
|---|---|
| Valve Sizes | ½" x 2" to 6" x 8" |
| Orifice Sizes | F, G, H, J, K, L, M, N, P, Q, R |
| Inlet Connection | Flanged ASME Class 300 RF |
| Outlet Connection | Flanged ASME Class 150 RF |
| Set Pressure Range | 5 – 300 psig |
| Design Temperature | -20°F to 750°F |
| Max Operating Temperature | 446°F |
| Body Material | Carbon Steel ASME SA 216 Gr. WCB |
| Seat/Disc Material | Stainless Steel (ASTM A182 F6A / A351 CF8) |
| Spring Material | Chrome-vanadium alloy steel |
| Overpressure (ASME I) | 3% |
| Overpressure (ASME VIII) | 10% |
| Blowdown (ASME I) | 2 – 6% |
| Blowdown (ASME VIII) | 7% |
| Max Backpressure | 10% of set pressure |
| Standards | ASME I, ASME VIII, ASME/API STD 527-1992 |
Applications
- Steam systems downstream of pressure reducing stations - Power boilers and steam generators - Heat exchangers, air coils, and process vessels - Flash steam recovery vessels on condensate return systems - Compressed air receivers and pneumatic equipment - Unfired pressure vessels requiring ASME-stamped protection
Frequently Asked Questions
Get a Quote
Contact PC Engineering for pricing, availability, and technical support for the Spirax Sarco SV74 Carbon Steel Safety Valve. Call us or fill in our inquiry form — our engineers will respond within 24 hours.
More from Spirax Sarco
- Spirax Sarco TD10, TD52M & TD259 Thermodynamic Steam Traps
- Spirax Sarco TD120M High Pressure Thermodynamic Steam Trap with Replaceable Seat
- Spirax Sarco TD32F Flanged Thermodynamic Steam Trap – Medium Pressure
- Spirax Sarco TD42 Thermodynamic Steam Trap – Stainless Steel, PN63
- Spirax Sarco TD42LC and TD42 Thermodynamic Steam Traps – IBR Certified
- Spirax Sarco TD42S2 Thermodynamic Steam Trap – Forged Steel, Socket Weld
Related Safety Valves
Brand
Find the losses before you invest in new equipment.
Steam and pump system walkthroughs that identify inefficiencies, energy losses and improvement priorities before any new product is specified.