Steam Air Vent Valve -- Float Thermostatic SS316
Combined Float Condensate and Thermostatic Air Vent for Steam Systems
Document No.SV-DS-VNT-002
RevisionRev A
DateMay 2026
ManufacturerSupreme Valves India, Ahmedabad, Gujarat, India
This datasheet covers combined float and thermostatic air vent valves in SS316 for simultaneous condensate drainage and air venting from steam systems, process heaters, and steam coils.
Technical Specifications
| Parameter | Specification |
|---|
| Size Range | DN15 to DN50 (1/2" to 2") |
| Pressure Rating | PN40 / Class 300 / 50 bar max operating |
| Body Material | CF8M (SS316) cast stainless steel |
| Float Material | SS304 thin-walled float, helium leak tested |
| Thermostatic Element | Nickel-iron bimetallic strip or balanced-pressure capsule |
| Valve Plug / Seat | SS316 + Stellite 6 overlay |
| Temperature Range | -20°C to +300°C (standard) |
| Operating Principle | Float opens for condensate; thermostatic element opens for air |
| End Connections | Screwed NPT / BSPT, socket weld, flanged |
| Discharge Capacity | Condensate: 100 to 2,000 kg/h; Air: 20 to 300 m³/h |
| Features | Dual float + thermostatic, self-acting, high capacity, renewable trim |
Materials of Construction
| Component | Material |
|---|
| Body | CF8M (SS316) investment cast, machined float chamber and thermostatic port |
| Bonnet | CF8M bolted bonnet with float guide and thermostatic element retention |
| Float | SS304 thin-walled welded float, 100% helium leak tested, guided by SS316 cage |
| Thermostatic Element | Nickel-iron bimetallic strip or balanced-pressure capsule in SS316 housing |
| Valve Plug | SS316 with Stellite 6 overlay for condensate port; SS316 needle for air port |
| Seat | Integral CF8M with Stellite 6 hard facing; replaceable seat rings optional |
| Spring | SS304 compression spring for air port valve closure |
| Gaskets | Spiral-wound SS316 + graphite for body/bonnet joint |
Testing & Inspection
| Test | Requirement |
|---|
| Test Standard | ISO 7842 / EN 26948 cold water test |
| Certification | CE, ISO 9001, IBR |
Applicable Standards
| Standard | Description |
|---|
| Design Standard | ISO 6552 / EN 26704 |
Notes
- Float chamber must be installed vertically with float moving freely; horizontal installation will cause float to bind and malfunction.
- Thermostatic element calibration must match steam saturation temperature at operating pressure; specify pressure at order.
- For superheated steam above 300°C, specify Inconel float and high-temperature bimetallic alloy.
- Float cage must be kept clear of debris and scale; install upstream strainer for dirty condensate service.
- Discharge piping must be routed to safe location and sized for full condensate capacity to prevent back-pressure flooding.
