Diaphragm Valves

Weir-type diaphragm valves have a raised saddle (weir) inside the body that the diaphragm presses against to close. The shorter diaphragm stroke gives better throttling control, lower actuator force, and longer diaphragm life. Best for clean, low-viscosity, non-coating fluids. Straight-through (full-bore) diaphragm valves have no weir - the diaphragm must span the full bore to close, requiring a longer stroke and higher actuating force. They are preferred for slurries, viscous media, fibrous fluids, and applications where any flow restriction behind a weir would cause solid build-up or coating.

Yes. We supply SS316L diaphragm valves with electropolished interior finish (Ra ≤ 0.4 μm or Ra ≤ 0.8 μm), EPDM/PTFE overlay or pure PTFE diaphragms, aseptic bonnet design (no dead zones or crevices for microbial growth), and full compliance documentation: 3-A Sanitary Standards, FDA 21 CFR, USP Class VI, and EHEDG Category I. These valves are used in WFI (Water for Injection), purified water, CIP/SIP cleaning circuits, bioreactor media lines, and sterile filling systems.

PTFE: broadest chemical resistance, lowest extractables, highest purity - specify for concentrated acids, solvents, and pharmaceutical service. EPDM: best for hot water, steam (CIP/SIP up to 143°C), and mild chemicals - widest availability for food and pharma. Natural Rubber: best flexibility at low temperatures and in vacuum service; suited for abrasive particle slurry. Neoprene: moderate oil and weather resistance. NBR: petroleum-based fluids and fuels. For unusual fluids, request a chemical compatibility chart or contact our technical team with fluid, concentration, and temperature data.

Yes - all Vajra diaphragm valves are available with pneumatic (air-operated diaphragm actuator), electric rotary actuator, or handwheel operation. Pneumatic actuators are most common: spring-return (fail-open or fail-closed) for ESD applications; double-acting for process control. Electric actuators allow operation where instrument air is unavailable. ISO 5211 top-works are standard. For pharmaceutical service, specify electropolished stainless steel actuator bodies and avoid aluminium in areas that contact cleaning chemicals.