API Β· ASME Β· DIN Β· EN standard industrial valves
Double Offset Butterfly Valves
Double offset butterfly valves move the shaft off both the centreline and the plane of the seat, so the disc lifts clear of the seat almost immediately on opening and rubbing wear drops sharply compared with a concentric design. The range covers DN50 to DN600 at PN10 to PN63 / Class 150 to Class 1500, wafer-ended, with ductile iron, WCB or SS304/SS316 body, matching disc choices up to aluminium bronze, SS410-series stems, 13Cr-to-cobalt-chromium hardfacing alloy body seats on a stainless-plus-graphite seal, operated by gear or actuator. Design follows API 609 / DIN 2559 / EN 593 with ASME B16.5 / DIN3202 F4 / EN558-1 face-to-face and API 598 testing. Selection turns on class against the offset-seat design, seat pairing versus temperature, and wafer length against the mating flanges.
Part of the Butterfly Valves family
Last updated: 2026-11
Family specifications
| size range | DN50 to DN600 |
|---|---|
| pressure class | PN10 to PN63, Class 150 to Class 1500 |
| pressure class | PN10 to PN63, Class150 to Class1500 |
| seat materials | 13Cr body seat, cobalt-chromium hardfacing alloy body seat, SS304 body seat, Stainless Steel + Graphite |
| disc materials | Ductile Iron, SS304, SS316, Aluminium Bronze |
| stem materials | SS410, SS420, SS416, SS431 |
| body materials | Ductile Iron, WCB, SS304, SS316 |
| end connections | Wafer Type |
| operation | Gear Operated, Electric Actuated, Pneumatic Actuated |
| design standards | API 609, DIN 2559, EN 593 |
| testing standards | API 598 |
| face to face | ASME B16.5, DIN3202 F4, EN558-1 |
| en593 pn40 doev size range | DN150 to DN3000 (6 inch to 120 inch) |
| en593 pn40 doev operating pressure | PN10, PN16, PN25, PN40 |
| en593 pn40 doev flange connection | Flange connection dimensions to EN 1092 |
| en593 pn40 doev top flange | ISO 5211 |
| en593 pn40 doev marking | EN 19 |
| en593 pn40 doev face to face | EN 558-1 series 14 (DIN 3202 F4) |
| en593 pn40 doev test standard | EN 12266-1, leak rate A |
| en593 pn40 doev bidirectional closure | Tight in both flow directions acc. to EN 1074-2 |
| en593 pn40 doev actuator flange | Actuator flange connection acc. to ISO 5211 |
| en593 pn40 doev shaft design | Anti-blowout shaft with shaft seal |
| en593 pn40 doev gear operator | Self-locking encapsulated maintenance-free worm gear, protection degree IP67, with position indicator and hand wheel |
| en593 pn40 doev design standard | DIN EN 593, drinking and service water shut-off up to 60 deg C |
| en593 pn40 doev service temperature | Drinking and service water up to 60 deg C |
| en593 pn40 doev application | Dams and hydropower, industrial, irrigation, power plants, sewage and wastewater treatment, water treatment |
| en593 pn40 doev body materials | Ductile cast iron GGG40 |
| en593 pn40 doev disc materials | Ductile cast iron GGG40 |
| en593 pn40 doev body seat | NiCr stainless steel welded overlay, micro finished |
| en593 pn40 doev disc seal | EPDM |
| en593 pn40 doev shaft materials | Stainless steel 1.4021 |
| en593 pn40 doev bolts materials | Stainless steel 1.4301 |
| en593 pn40 doev shaft bearings | Maintenance-free zinc-free bronze |
| en593 pn40 doev certification | EN 10204 3.1 |
| en593 pn40 doev coating | Inside and outside epoxy coated, blue RAL 5010; disc epoxy coated |
| en593 pn40 doev operation | Gearbox with hand wheel; electric, pneumatic or hydraulic actuator optional |
| en558 s13 doev size range | DN150 to DN2000 (6 inch to 80 inch) |
| en558 s13 doev operating pressure | PN10, PN16 |
| en558 s13 doev top flange | ISO 5211 |
| en558 s13 doev marking | EN 19 |
| en558 s13 doev face to face | EN 558-1 series 13 (BS 5155), double flanged short |
| en558 s13 doev test standard | EN 12266-1 |
| en558 s13 doev design construction | Double flanged valve with double eccentric disc, self-adjusting elastomer seat attached to disc and retaining ring |
| en558 s13 doev operation | Gearbox with hand wheel; electric, pneumatic or hydraulic actuator optional |
| en558 s13 doev flange connection | EN 1092 |
| en558 s13 doev actuator flange | ISO 5211 |
| en558 s13 doev body materials | Ductile cast iron GGG40 |
| en558 s13 doev disc materials | Ductile cast iron GGG40 |
| en558 s13 doev body seat | NiCr stainless steel welded overlay, micro finished |
| en558 s13 doev disc seal | EPDM |
| en558 s13 doev shaft materials | Stainless steel 1.4021 |
| en558 s13 doev bolts materials | Stainless steel 1.4301 |
| en558 s13 doev shaft bearings | Maintenance-free zinc-free bronze |
| en558 s13 doev certification | EN 10204 3.1 |
| en558 s13 doev coating | Inside and outside epoxy coated, coating thickness over 250 um, blue RAL 5010 |
| en558 s13 doev test leak rate | Leak rate A per DIN EN 12266-1, tight in both flow directions acc. EN 1074-2 |
| awwa c504 doev size range | DN150 to DN2600 (6 inch to 104 inch) |
| awwa c504 doev operating pressure | 150 PSI, 250 PSI |
| awwa c504 doev flange connection | ANSI CL150 (ASME B16.1) |
| awwa c504 doev top flange | EN ISO 5211 F rating |
| awwa c504 doev marking | NSF |
| awwa c504 doev face to face | AWWA C504 short body |
| awwa c504 doev test standard | AWWA C504 / NSF 61/372 |
| awwa c504 doev application | Dams and hydropower, industrial, irrigation, power plants, sewage and wastewater treatment, water treatment |
| resilient doev size range | 50 NB to 1200 NB (larger sizes on request) |
| resilient doev operation | Lever, gear, pneumatic actuator, pneumatic cylinder, electrical (motorized) actuator, manual override arrangement with pneumatic and electrical actuator |
| resilient doev design standards | BS 5155, API 609, IS 13095 |
| resilient doev face to face | BS 5155, API 609, IS 13095 (wafer short) |
| resilient doev end connections | Wafer type, lug type, flanged end to suit ANSI / DIN / BS / JIS / IS |
| resilient doev testing standards | BS 5155, BS 6755 Part I, API 598, IS 13095 |
| resilient doev seat temperature epdm | -34 deg C to 107 deg C (EPDM, resilient seated) |
| resilient doev seat temperature ptfe | 4 deg C to 121 deg C (PTFE) |
| resilient doev seat temperature buna n | -12 deg C to 82 deg C (Buna-N) |
| resilient doev seat temperature neoprene | -6 deg C to 93 deg C (Neoprene) |
| resilient doev seat temperature hypalon | -17 deg C to 135 deg C (Hypalon) |
| resilient doev seat temperature fkm | -12 deg C to 135 deg C (FKM); high-temperature FKM option -12 deg C to 204 deg C |
| resilient doev design feature seat | Resilient seal encapsulated in the disc, fully adjustable and replaceable; one-piece seal retaining ring |
| resilient doev body seat ring materials | SS 304 standard for body seat ring and seal retaining ring, other materials optional |
| resilient doev seating options | Available in metal to metal seating |
| resilient doev shaft orientation | Horizontal shaft standard, vertical shaft mounting optional |
| resilient doev service capability | Suitable for throttling service, low head loss |
| resilient doev operator standard | Worm gear operator supplied as standard, other means of operation on request |
| resilient doev design variant | Double eccentric design |
| resilient doev applications | Water works, power plants, sewage plants, process industries, chemical and petrochemical plants |
| mounted disc doev size range | DN150 to DN2500 |
| mounted disc doev design variant | Double eccentric, mounted disc |
| mounted disc doev design standard | EN 593 |
| mounted disc doev face to face | EN 558-1 series 14, series 13 optional |
| mounted disc doev flange connection | EN 1092-2 |
| mounted disc doev pressure class | PN 10, PN 16, PN 25, PN 40 |
| mounted disc doev operator standard | Worm gearbox and handwheel |
| mounted disc doev actuator ready | Prepared for actuator |
| mounted disc doev body seat | Body seat made of stainless steel, welded and microfinished |
| mounted disc doev body disc materials | Body and disc made of ductile iron, epoxy powder coated |
| mounted disc doev sealing ring | Sealing ring made of elastomer |
| mounted disc doev retaining ring | Retaining ring made of steel, epoxy powder coated |
| mounted disc doev connections materials | All connections made of stainless steel |
| mounted disc doev shaft bearings | Bearing system made of bronze, self lubricating |
| mounted disc doev shaft materials | Shafts made of stainless steel |
| mounted disc doev handwheel material | Handwheel made of cast iron, epoxy powder coated |
| ip68 doev size range | DN150 to DN1600 |
| ip68 doev face to face | EN 558-1 series 14 |
| ip68 doev flange connection | EN 1092-2 |
| ip68 doev pressure class | PN 10, PN 16 |
| ip68 doev operator standard | Wormgearbox and handwheel, protection class IP 68 |
| ip68 doev protection class | IP 68 |
| ip68 doev installation | Applicable for below ground installation, simple assembly of the extension spindle |
| ip68 doev actuator ready | Applicable for actuator |
| ip68 doev body seat | Sealing seat made of stainless steel, welded and microfinished |
| ip68 doev body disc materials | Body and disk made of ductile iron, epoxy powder coated inside and out |
| ip68 doev sealing ring | Sealing rings made of elastomer |
| ip68 doev retaining ring | Retaining ring made of stainless steel |
| ip68 doev shafts connections | Shafts and all connections made of stainless steel |
| ip68 doev shaft bearings | Bearings made of bronze |
| ip68 doev handwheel material | Handwheel made of cast iron, epoxy powder coated |
| fbe doev design variant | Double eccentric design, double flanged, bi-directional |
| fbe doev design standards | BS EN 593, EN 1074-1 and 2, IS 13095 |
| fbe doev face to face | EN 558, ISO 5752, IS 13095 |
| fbe doev top flange | ISO 5211 |
| fbe doev flange drilling | EN 1092-2 PN10 and PN16, IS 9523, IS 1538 |
| fbe doev test pressure | Pressure testing acc. EN 1074-1 and 2, IS 13095, EN 12266-1 and 2; shell test 1.5 x PN, seat test 1.1 x PN |
| fbe doev body design | Cast ductile iron, double flanged design, bi-directional applications |
| fbe doev seat options | Stainless steel seats, soft seated |
| fbe doev shaft options | SS 420, Duplex |
| fbe doev coating | NSF/WRAS approved fusion bonded epoxy coating, minimum 250 microns (300 microns optional) |
| fbe doev seat repairability | Easy maintenance: replaceable valve seal |
| fbe doev sealing technology | Double offset sealing technology with soft sealing element on the disc |
| eccentric line design variants | Concentric, single eccentric, double eccentric and triple eccentric (offset) types |
| eccentric line end connections | Wafer, flanged, butt-weld, lugged and grooved |
| eccentric line flange standards | EN 1092-2, BS 4504, BS 10 Table D or E, ASME B16.1, ASME B16.42, ASME B16.5, ASME B16.47 Category A or B |
| eccentric line face to face standards | EN 558-1 series 20, BS 5155 wafer-short type, ISO 5752, MSS SP-68 |
| eccentric line actuator flange | ISO 5211 |
| eccentric line test standard | EN 12266-1 |
| body seat | 13Cr, cobalt-chromium hardfacing alloy, SS304, SS316 |
| end connection | Wafer Type |
| flanged end dimension | DIN, ANSI B16.1, BS4504, EN1092 |
| shutoff direction | Bi-Directional |
| maintenance design | All parts replaceable, in-line maintenance available |
Ordering & documentation
Documents
Ask for the documentation set with the inquiry β 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 β 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 double offset butterfly valves?
The published specification for this family lists API 609, DIN 2559, EN 593 as the design standards. Testing follows API 598.
What sizes and pressure ratings are available for double offset butterfly valves?
The published size range is DN50 to DN600, and the published pressure ratings are PN10 to PN63, Class 150 to Class 1500. Availability of a specific size and rating is confirmed at quotation.
What materials are double offset butterfly valves available in?
The published specification lists body materials: Ductile Iron, WCB, SS304, SS316. Material availability for a specific size and rating is confirmed at quotation.
What end connections do double offset butterfly valves support?
The published specification lists Wafer Type as the available end connections. The connection for a specific size is confirmed at quotation.
What should a quotation inquiry for double offset butterfly valves include?
The governing standard and class, nominal size, body and seat materials, the service medium with temperature, and the destination β anything missing is confirmed during quotation.
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