API · ASME · DIN · EN standard industrial valves
Cast Iron Diaphragm Valves
Cast iron diaphragm valves isolate or throttle utility flows by pressing a flexible diaphragm against a weir, so the wetted metal stays out of the medium — the body only backs the lining and elastomer that actually see the fluid. The range covers bodies and discs in cast iron, ductile iron or WCB with NBR or EPDM lining and diaphragm, DN15 to DN250 at PN6 to PN16 or Class 150, flanged ending, and manual, electric or pneumatic operation under BS 5156, BS 6755, ASME B16.5, BS 4505 and EN 1092. Selection turns on diaphragm elastomer versus temperature and chemistry, solids content, cycle frequency and the ease of swapping the diaphragm in place.
Part of the Diaphragm Valves family
Last updated: 2026-11
Family specifications
| body materials | Cast Iron, Ductile Iron, WCB |
|---|---|
| disc materials | Cast Iron, Ductile Iron, WCB |
| lining materials | NBR, EPDM |
| diaphragm materials | NBR, EPDM |
| suitable medium | Graphite, PTFE |
| size range | DN15 to DN250 |
| pressure class | PN6 to PN16, Class150 |
| end connections | Flanged |
| design standards | BS 5156, BS 6755, ASME B16.5, BS 4505, EN 1092 |
| operation | Manual, Electric Actuated, Pneumatic Actuated |
| weir type flange connections | GB/T9113, EN1092, ANSI B16.10, JIS B2212, BS4504 |
| weir type size span | DN20 to DN250 |
| weir type pressure ratings | PN6, PN10, PN16 |
| weir type body bonnet materials | Cast Iron, Ductile Iron, Cast Steel, Stainless Steel |
| weir type disc materials | Cast Iron, Ductile Iron, Cast Steel, Stainless Steel |
| weir type lining options | Unlined, Rubber, NBR, EPDM, NR, PTFE |
| weir type diaphragm options | Rubber, PTFE |
| weir type actuation options | Handwheel, Pneumatic, Electric |
| weir type suitable media | Corrosive media, Viscous media, Slurry media |
| pneumatic actuated model series | G641J-6, G641J-10, G641J-16 |
| pneumatic actuated size span | DN15-DN600 |
| pneumatic actuated pressure levels | PN6, PN10, PN16 |
| pneumatic actuated temp range | -9 to 80 °C |
| pneumatic actuated actuator modes | Normally Closed, Normally Open |
| pneumatic actuated part materials | Body: cast iron, ductile iron, carbon steel, stainless steel; bonnet: cast iron, ductile iron, carbon steel, stainless steel; lining: rubber; diaphragm: rubber; disc: cast iron, carbon steel; cylinder: ductile iron; piston: carbon steel; stem: carbon steel; handwheel: cast iron |
| pneumatic actuated lining test | EDM lining spark test |
| weir bs5156 size span | 3/4-16 inch (DN20-DN400) |
| weir bs5156 pressure ratings | PN10, PN16, Class 125 LB, Class 150 LB |
| weir bs5156 design standards | BS 5156-85, MSS SP-88, GB 12239-89 |
| weir bs5156 face to face standards | BS 5156-85, ANSI B16.10, GB 12221-85, DIN 3202 |
| weir bs5156 flange standards | BS, DIN PN10 & PN16, JIS 10K, ANSI B16.5 Class 125 & 150 |
| weir bs5156 inspection test standards | BS 5156, MSS SP-82, GB/T 13927 |
| weir bs5156 face to face series | EN 558-1, BS 5156, DIN 3202 Series F1 |
| weir bs5156 body materials | Cast Iron, Ductile Iron, Carbon Steel, Stainless Steel, Duplex Stainless Steel, ASTM A216 WCB, ASTM A351 CF8, CF8M |
| weir bs5156 lining materials | Hard Rubber (Ebonite), Natural Rubber, Neoprene, Hypalon, Butyl, EPDM, FEP, PFA |
| weir bs5156 diaphragm materials | Natural Rubber, Neoprene, Hypalon, Butyl, EPDM, Silicone, PTFE-backed Neoprene |
| weir bs5156 stem materials | AISI 410, AISI 304, AISI 316 |
| weir bs5156 operation options | Handwheel, Pneumatic, Electric |
| weir bs5156 temp range | -29°C to 150°C |
| weir bs5156 handwheel materials | Ductile Iron, Aluminum Alloy |
| weir bs5156 lining custom options | Glass, ETFE, PFA, PVDF, ECTFE |
| actuated lined flange standards | ASME B16.5, BS 4504, EN 1092 |
| actuated lined body bonnet disc materials | Body/bonnet and disc: Cast Iron, Ductile Iron, WCB, CF8, CF8M, CF3, CF3M |
| actuated lined elastomer options | NR, BR, IIR, CR, NBR, EPDM, CSPE |
| actuated lined suitable medium | Graphite, PTFE |
| actuated lined temp range | -20 to 120 °C |
| actuated lined pressure rating | PN6 to PN16, Class 150 |
| actuated lined size range | DN50-DN300 (2"-12") |
| actuated lined configuration options | Lined or unlined, Electric or pneumatic actuator, Optional locking device, Position indicator |
| actuated lined test and marking | tested to BS 6755, marked per MSS SP-25 |
| lining | NBR, EPDM |
| diaphragm | NBR, EPDM |
Ordering & documentation
Documents
Ask for the documentation set with the inquiry — typical items (material certificates, test reports to the listed inspection standard, dimensional drawings) are confirmed and supplied with the quotation.
Quotation
Send the medium, temperature, pressure, size and connection for a quotation-ready inquiry. Lead time, MOQ and price are confirmed at quotation, together with the documents to be supplied with the order.
Sample & supply
Supply terms, order quantities and lead time are agreed per order — state the destination country and required schedule with the inquiry.
Storage & shipping
Store valves with seats and seals protected from UV, ozone and deformation, and keep end-face protectors on until installation; storage limits and shipping arrangements for the selected materials are confirmed at quotation.
Frequently asked questions
What standards govern the design and testing of cast iron diaphragm valves?
The published specification for this family lists BS 5156, BS 6755, ASME B16.5, BS 4505, EN 1092 as the design standards.
What sizes and pressure ratings are available for cast iron diaphragm valves?
The published size range is DN15 to DN250, and the published pressure ratings are PN6 to PN16, Class150. Availability of a specific size and rating is confirmed at quotation.
What materials are cast iron diaphragm valves available in?
The published specification lists body materials: Cast Iron, Ductile Iron, WCB. Material availability for a specific size and rating is confirmed at quotation.
What end connections do cast iron diaphragm valves support?
The published specification lists Flanged as the available end connections. The connection for a specific size is confirmed at quotation.
What should a quotation inquiry for cast iron diaphragm valves include?
The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination — anything missing is confirmed during quotation.
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