BS 5156 Diaphragm Valve

A BS 5156 diaphragm valve is a linear-motion isolation and throttling valve built to British Standard 5156. Utilizing either a weir or straight-through full-bore body, it features a flexible elastomeric or PTFE diaphragm that acts as both the moving shut-off element and an absolute barrier separating the process media from the upper bonnet and stem. This design eliminates stem-leakage fugitive emissions and protects internal mechanical components from corrosion or fouling. Commonly manufactured in cast or ductile iron and enhanced with protective inner linings like hard rubber, neoprene, or PFA, this robust valve is the industrial benchmark for handling aggressive chemical media, abrasive mining slurries, and water treatment systems. Partner directly with verified manufacturers in China via our specialized B2B marketplace to eliminate middleman markups and secure factory-direct pricing on certified BS 5156 diaphragm valves.