SPIRAX SARCO · SAFETY VALVES
Spirax Sarco SV405 Series Safety Valves – Full Nozzle Safety Valves for Steam & Air
Spirax Sarco SV405/SV406 safety valves for steam & air. Low pressure, compact design for sterilisers & compressors. Get specs & quote from PC Engineering
Overview
The Spirax Sarco SV405 Series comprises full nozzle safety valves engineered for steam and air service in non-critical industrial processes. These valves are designed for applications requiring low flow, low pressure, and low temperature protection against overpressure conditions.
The series includes four variants: SV405 (brass body with 304 SS nozzle), SV406 (stainless steel body with 316 SS nozzle), SV405X (brass body with 316 SS nozzle for enhanced corrosion resistance), and SV405P (compact ring-pull design for space-constrained installations). All variants feature Viton O-ring seat seals as standard, ensuring reliable sealing performance.
These safety valves comply with API 527 seat tightness standards and meet European Pressure Equipment Directive 97/23/EC Category 4 requirements for Group 2 gases, carrying the CE mark for regulatory compliance.
Key Features
- Full nozzle design for consistent flow characteristics
- Multiple body and nozzle material combinations for application flexibility
- Viton O-ring seat seal for reliable tightness
- Compact dimensions suitable for limited installation spaces (SV405P with ring-pull)
- 10% overpressure and 10% blowdown limits for steam and gas
- Derated coefficient of discharge: 0.78
- CE marked, compliant with PED 97/23/EC Category 4
- Available with manufacturer's Typical Test Report
Specifications
| Parameter | Value | |
|---|---|---|
| Set Pressure Range | 1 bar g to 10 bar g (1.65 bar g min for SV405P) | |
| Maximum Backpressure | 10% of set pressure | |
| Temperature Range | -20°C to +184°C (Viton seat) | |
| Inlet Connection | ½" or ¾" BSP taper male (BS 21 R) or NPT | |
| Outlet Connection | ¾" BSP parallel female (BS 21 Rp) or NPT | |
| Orifice Size | 8 mm | |
| Lift | 2 mm | |
| Weight | 0.70 kg (SV405P) / 0.75 kg (SV405, SV405X, SV406) | |
| Body Material | Brass EN 12164 CW617N (SV405, SV405P, SV405X) / SS 1.4409 (SV406) | |
| Nozzle Material | SS 304 (SV405, SV405P) / SS 316 (SV405X, SV406) | |
| Seat Seal | Viton FPM 75 | |
| Max Cold Hydraulic Test Pressure | 20 bar g | |
| Standards | API 527, EN ISO 4126, PED 97/23/EC | |
| Set Pressure (bar g) | Dry Saturated Steam (kg/h) | Air at 0°C, 1013 mbar (Nm³/h) |
| 1.0 | 42 | 61 |
| 2.0 | 63 | 88 |
| 4.0 | 105 | 149 |
| 6.0 | 146 | 209 |
| 8.0 | 187 | 270 |
| 10.0 | 228 | 330 |
Applications
The SV405 Series safety valves are suitable for overpressure protection in:
- Sterilisers and autoclaves - Small air compressors - Pressure vessels in process industries - Steam distribution systems (low pressure) - Pharmaceutical and food processing equipment - HVAC and utility steam systems - Laboratory and pilot plant installations
Frequently Asked Questions
Get a Quote
Contact PC Engineering for pricing, availability, and technical support for Spirax Sarco SV405 Series Safety Valves. Call us or fill in our inquiry form — our engineers will respond within 24 hours.
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