Diaphragm for Pneumatic Diaphragm Valve

Detail

Parameters

Core role
- As the core sealing and drive component of pneumatic diaphragm valves,The diaphragm directly controls the flow of the medium through pneumatic pressure deformation, achieving zero-leakage sealing (leakage rating up to ANSI Class VI).
- Dual roles: It serves as both a dynamic seal and a pressure transmission element.
Key Performance Parameters
• Pressure Rating: 0.1 to 1.6 MPa (Special designs available up to 2.5 MPa) • Temperature Adaptability: -40°C to 180°C (depending on material) • Cycle life: 500,000 to 2,000,000 cycles (requires optimized valve body design)

Type	Material Composition	Optimal Scenarios	Extreme operating conditions
Rubber diaphragm	NBR/EPDM/Fluorocarb	Water treatment, food and pharmaceuticals (low cost)	Poor oil resistance (except NBR)
PTFE composite membrane	PTFE + Fiber Reinforced Layer	Strongly corrosive media (such as concentrated sulfuric acid, chlor-alkali)	Becomes brittle and prone to cracking at low temperatures (use with caution below -50°C)
All-metal diaphragm	316L Stainless Steel/Hastelloy	Ultra-high-temperature steam, nuclear-grade applications	Poor elasticity, requiring higher drive air pressure

Golden Rules for Model Selection:

Chemical compatibility takes precedence: Refer to the Chemical Corrosion Handbook for material selection.
Dynamic Operating Condition Compensation: For frequent opening and closing, high-elasticity materials (such as fluororubber) should be selected.

Model Selection Recommendations