COMMON VALVE TYPES
Diaphragm Valves
The families that appear on first RFQs and Chinese export quotes. Shared names are not interchangeable designs.
Choosing Diaphragm Valves
A diaphragm valve closes the passage with a flexible diaphragm that separates the operating mechanism from the fluid. Weir and straight-through bodies are different choices. Selection depends on the body, diaphragm and service together, including cleaning chemicals and temperature cycles where relevant.
What to include in the RFQ
- Specify weir or straight-through construction and provide the fluid composition and solids content.
- Request the exact diaphragm material, backing construction and body or lining material.
- Give process and cleaning temperatures, pressures and cycling frequency as separate conditions.
- Where cleanliness matters, request drainability, surface finish and maintenance documentation for the offered design.
Selection scenario
For a chemical-dosing branch, review both the wetted body and diaphragm against the actual concentration. For a clean process, add the cleaning cycle and installation orientation; a chemically resistant diaphragm alone does not establish hygienic suitability.
Common selection mismatch
Do not infer a complete valve temperature limit from a generic elastomer chart. Obtain the assembly rating and the applicable pressure-temperature combination.