Elastomeric diaphragm isolates the actuating mechanism from the process fluid, providing zero-contamination shut-off for corrosive, abrasive, and purity-critical applications.
The diaphragm valve uses a flexible elastomeric membrane stretched across the valve body bore to provide positive shut-off. As the handwheel or actuator compresses the diaphragm against the weir or straight-through body seat, flow is blocked without any contact between the actuating mechanism and the process fluid. This feature makes diaphragm valves unique — they can handle highly corrosive, abrasive, or contamination-sensitive fluids without the risk of stem leakage or metallic contamination.
VALVAX diaphragm valves are designed to BS 5156 and BS EN 13397. Available in weir-type (standard) and full-bore straight-through body configurations. Weir-body valves offer the best throttling control and are preferred for clean chemical and pharmaceutical service. Straight-through bodies handle slurries and fibrous media that would damage a weir seat.
| Parameter | Value |
|---|---|
| Design Standard | BS 5156 / BS EN 13397 |
| Size Range | ½″ – 12″ (DN15 – DN300) |
| Pressure Rating | PN10 / PN16 |
| Face to Face | BS 5156 / ISO 7259 |
| End Connections | RF Flanged / Plain end / Wafer |
| Body Material | Cast Iron / GGG-40 / CF8M / PP / PVDF |
| Lining | Natural rubber / EPDM / Neoprene / PTFE |
| Diaphragm | NR / EPDM / Neoprene / Viton / PTFE overlay |
| Design Temp. | -10°C to +130°C (elastomer dependent) |
| Testing | BS 5156 / EN 13397 |
GG-20 / NR Lining
General water, slurry, and mild chemical service. Most economical configuration for municipal and industrial water.
GGG-40 / EPDM
Wider chemical compatibility than NR. Suitable for acids, alkalis, and ozone-treated water service.
CF8M / PTFE Lining
Pharmaceutical, food, and ultra-pure chemical service. FDA-compliant PTFE lining prevents contamination.
Polypropylene / PVDF
Highly aggressive acid and alkali service where metallic body materials would be attacked. Full plastic construction.
API and formulation process lines where zero contamination and CIP/SIP cleaning are mandatory.
Aggressive acid, caustic, solvent, and oxidising chemical streams that attack metallic seat designs.
Chlorinated water, ozone treatment, and slurry handling in municipal and industrial water plants.
Hygienic process lines in CF8M-PTFE for fruit juices, dairy, brewing, and beverage filling operations.
Abrasive slurry, tailings, and mineral acid service where the rubber-lined body resists abrasion and corrosion.
Tell us your fluid chemistry, temperature, pressure, and whether you need throttling or on-off service — we will specify the right diaphragm valve.