Water Treatment & Desalination
Application Specification

Diaphragm Valves for Water Treatment & Desalination

Butterfly, gate, check, and diaphragm valves for water treatment, RO desalination, and municipal water distribution - DI, CS, SS 316 materials.

Which diaphragm valves are used for water treatment & desalination?

Water treatment plants, reverse osmosis (RO) and multi-stage flash (MSF) desalination, and municipal water distribution systems require valves that provide low-maintenance service life, corrosion resistance to chlorinated and saline water, and compliance with drinking water safety standards. Ductile iron and stainless steel designs with EPDM or PTFE seals are the norm.

Diaphragm Valve (Rubber-Lined)

Chemical dosing and slurry handling in WTP filter backwash and sludge lines

MaterialsDI body with natural rubber or EPDM lining; PP or PVDF for chemical service
Pressure ClassPN 10 / PN 16
StandardsISO 16138, EN 13397

Critical Requirements

  • Drinking water contact compliance: WRAS / NSF 61 / IS potable water certification for epoxy coatings and elastomers
  • Corrosion protection: fusion-bonded epoxy (FBE) or Rilsan (polyamide) coating for buried ductile iron valves
  • EPDM elastomers - chlorine and ozone resistant for treated water service
  • Large bore availability - DN 200–DN 1200 butterfly valves for major distribution mains
  • Actuator compatibility for remote operation in WTP control systems
  • Extended service life (20–40 years expected) - heavy-duty ductile iron construction

Service Challenges

  • Chlorinated water (up to 5 ppm residual Cl₂) - EPDM seats, FBE-coated iron body required
  • Seawater and brackish water (RO feed) - SS 316 or duplex for high chloride concentration
  • Sludge and filter backwash - full-bore butterfly or diaphragm to prevent clogging
  • Chemical dosing (alum, PAC, sodium hypochlorite, lime) - PP or PVDF-lined diaphragm valves
  • Ozonated water - EPDM or PTFE seats; carbon steel and most rubbers deteriorate in ozone

Vajra Diaphragm Valves

Elastomer-lined valves for corrosive, abrasive, and sterile applications.

See the full Diaphragm Valves range

Other valves for water treatment & desalination

Diaphragm Valves for other applications

Reviewed by Product Engineering, Vajra Industrial SolutionsDiscipline: Valve Product EngineeringLast reviewed: 20 June 2026

Connected Engineering

Need diaphragm valves for water treatment & desalination?

Send your line list or datasheet — we supply diaphragm valves for water treatment & desalination to the right material, class and standard with full certification and a 24-hour quote.

Relevant Products

Engineering references