Weir Type Diaphragm Valves
Weir-type diaphragm valves are the classic diaphragm valve geometry, in which the body casting carries a raised weir down its centre and the flexible diaphragm is pressed against that weir to close. Because the diaphragm only has to flex a short distance onto the weir, travel and stress are low, diaphragm life is long, and the valve gives precise, repeatable throttling as well as tight isolation. As with all diaphragm valves, the diaphragm seals the medium completely away from the stem and bonnet, so there is no stem leak path or wetted packing.
The weir design is the preferred choice for control and throttling duty, for clean and moderately solids-bearing liquids, and for sterile and high-purity service where the short diaphragm stroke and smooth seat support hygienic operation. It is widely used in water treatment, chemical dosing, pharmaceutical and fine-chemical lines. Design and testing follow BS EN 13397, BS 5156, MSS SP-88 and ASME B16.34, typically across PN 10-16 / ASME Class 150 and sizes from about 1/2" to 12".
Bodies are commonly cast or ductile iron, WCB carbon steel or CF8M stainless, frequently rubber-, glass- or PFA-lined for corrosive media. The diaphragm is selected to the duty, EPDM, butyl, natural rubber, neoprene, Hypalon or Viton for general and chemical service, and PTFE backed by EPDM for aggressive or sanitary use. End connections include flanged ANSI B16.5 / EN 1092, threaded and sanitary clamp/weld ends.
Operation is by manual handwheel or pneumatic actuator for throttling and modulating control. Himalay's MSME partners manufacture weir-type diaphragm valves with testing per API 598 / BS EN 12266-1 / ISO 5208, material traceability, and PED-CE (EU), SABER (Saudi Arabia) and NACE MR0175 (sour service where applicable) coordinated as part of the standard order flow.
