API · ASME · DIN · EN standard industrial valves
Ductile Iron Diaphragm Valves
Ductile iron diaphragm valves put a higher-strength body behind the same weir-sealing idea: a flexible diaphragm meets a body weir so the elastomer and lining — not the pressure shell — carry the medium. The range covers bodies and discs in ductile iron, cast 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, line pressure against the PN band, solids content and maintenance access for diaphragm replacement.
Part of the Diaphragm Valves family
Last updated: 2026-11
Family specifications
| body materials | Ductile Iron, Cast Iron, WCB |
|---|---|
| disc materials | Ductile Iron, Cast 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 |
| ksd design variant | Weir type |
| ksd design standard | BS 5156, MSS SP-88 |
| ksd body materials | Ductile iron |
| ksd lining materials | EPDM lined |
| ksd nominal size | DN50 (2 inch) |
| ksd nominal pressure | PN16, Class 150 LB |
| ksd end connection | RF flanged |
| kss design variant | Straight through |
| kss design standard | BS 5156, MSS SP-88 |
| kss body materials | Ductile iron (DI) |
| kss lining materials | Rubber or fluorine lining |
| kss nominal size | 2 inch (DN50) |
| kss nominal pressure | PN10, Class 150 LB |
| kss end connection | RF flanged |
| ksn body materials | Ductile iron GGG40 |
| ksn design standard | BS 5156, MSS SP-88 |
| kxd size range | DN15 to DN300 |
| kxd nominal pressure | PN10, PN16 |
| kxd body materials | Ductile iron / GGG50 |
| kxd seal materials | Ductile iron + PTFE |
| kxd shaft materials | Stainless steel 304 |
| kxd suitable medium | Water, waste water, air, oil |
| kxd temperature range | -20 deg C to 250 deg C |
| kxs design variant | Straight through |
| kxs size range | DN15 to DN300 |
| kxs nominal pressure | PN10, PN16 |
| kxs body materials | Ductile iron / GGG50 |
| kxs seal materials | Ductile iron + EPDM |
| kxs temperature range | -20 deg C to 250 deg C |
| cm design standard | BS 5156 |
| cm flange connections | GB/T 9113, EN 1092, ANSI B16.10, JIS B2212, BS 4504 |
| cm size range | DN20 to DN250 |
| cm nominal pressure | PN6, PN10, PN16 |
| cm body materials | Cast iron, ductile iron, cast steel, stainless steel |
| cm disc materials | Cast iron, ductile iron, cast steel, stainless steel |
| cm lining options | Unlined, rubber, NBR, EPDM, NR, PTFE |
| cm diaphragm options | Rubber, PTFE |
| cm operation | Handwheel, pneumatic, electric motorized |
| tt design variant | Straight-through diaphragm valve |
| tt operating pressure | Designed for 125 to 200 PSIG operating pressure |
| tt face to face | Compact design conforming to ASME/ANSI B16.10 (short body) |
| tt diaphragm options | EPDM, neoprene (CR), soft natural rubber (NR) |
| 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 ductile 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 ductile 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 ductile iron diaphragm valves available in?
The published specification lists body materials: Ductile Iron, Cast Iron, WCB. Material availability for a specific size and rating is confirmed at quotation.
What end connections do ductile 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 ductile 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.
Knowledge: selection guides
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