PRODUCT

DI Body U type flange end china butterfly valve

DI Body U type flange end china butterfly valve

Product Attributes :

Specifications:

Size: DN50-DN1600

Pressure: PN10/PN16/125LB/150LB

Product Deign : EN593 ,API609

Product Description

Flange End Butterfly Valve – DN50 to DN2000, PN10 / PN16 / ANSI Class 150

A double-flanged, resilient seated butterfly valve with U-section seat, ISO 5211 mounting flange and worm gear or lever operation. Precision drilled to DIN, ANSI, JIS and BS standards for bubble-tight shutoff on water, HVAC, chemical and general industrial pipelines.

Size: DN50 – DN2000
PN10 / PN16 / PN25
API 609 / EN 593
ISO 5211 Pad

Request a Quote View Dimensions

Factory-direct supply · 100% hydrostatic and shell tested · OEM nameplate and custom drilling available.

Flange end butterfly valve DN50 to DN2000 with worm gear operator

Double flange butterfly valve, PN10 / PN16, epoxy coated body

DN50 – DN2000

Nominal size range

PN10 / PN16 / PN25

DIN, BS, ISO, JIS, ANSI

-10°C to 120°C

Depending on seat material

Bubble-Tight

API 598 / ISO 5208 Rate A

Key Features at a Glance

U-Section Resilient Seat

The U-shaped rubber seat sits in a dovetail groove on the body, so it is locked in place and cannot be displaced by high flow velocity. Replacement is possible without removing the valve from the line.

Bi-Directional Sealing

Tight in both flow directions, allowing the valve to be installed without regard to upstream or downstream side and to be used as a terminal end-of-line valve.

Low Operating Torque

Centre-line disc geometry with a polished stem and PTFE-lined bushing keeps breakaway torque low — 90° quarter-turn travel with a hand lever or worm gearbox.

ISO 5211 Actuation Pad

Standardised top flange (F05 to F40) accepts lever, worm gear, electric or pneumatic actuators, with a square or keyed stem drive for simple field conversion.

Technical Specifications

Nominal size	DN50 – DN2000 (2" – 80")
Nominal pressure	PN10, PN16, PN25 (PN10 / PN16 dimensions listed below); ANSI Class 150 on request
Body type	Double flanged, centre-line (concentric) disc, face-to-face to ISO 5752 series 20 / API 609 / BS 5155
Body material	Carbon steel, stainless steel, cast iron, ductile iron, aluminium bronze
Disc material	Aluminium bronze, CF8M (SS316), ductile iron, WCB — optionally rubber lined
Seat / O-ring material	EPDM, PTFE, Buna-N (NBR), Hypalon
Stem material	Carbon steel, stainless steel 304, stainless steel 316
Bushing / pin	PTFE or self-lubricating bushing; SS316 / SS416 / SS304 pins
End connection	Flanged (double flange), drilled to DIN PN10/16/25, ANSI B16.1, BS 4504, ISO PN10/16, JIS B2212/2213, BS 10 Table D & E
Operation	Hand lever, worm gearbox, electric actuator, pneumatic actuator
Working temperature	-10°C to 120°C (EPDM / NBR); up to 150°C with PTFE seat, subject to pressure derating
Application media	Cold and hot water, sea water, sewage, air, steam (with PTFE), dilute acids and alkalis, food-grade liquids
Coating	Fusion bonded epoxy, 250 µm minimum, blue RAL 5015 or customer colour

Pressure and temperature ratings are mutually dependent. Please confirm the actual media, concentration and working temperature with our engineering team before ordering.

Product Description: How a Flange End Butterfly Valve Works

The flange end butterfly valve offers reliable performance, a compact and lightweight structure, and a true flanged connection that bolts directly between two pipe flanges for easy installation and removal. A 90° quarter turn opens or closes the line, and with a worm gear drive the operating torque stays low even on large diameters. The valve seals in both directions, its flow characteristic is close to linear, and it delivers good regulating and shutoff performance.

There is a wide choice of body, disc and seat materials, so the same valve platform can be configured as a terminal end-of-line valve, a pump isolation valve or a modulating control valve. The body of the rubber-lined version is fitted with a removable soft rubber sleeve, or with a skeleton-reinforced removable rubber sleeve; on some designs a layer of rubber is bonded to the internal body surface. To improve corrosion resistance, the disc can also be fully rubber lined, with the compound selected according to the corrosiveness of the medium.

Because this design uses a "U"-shaped sealing ring, the disc must be of the centre-line type — which is why the product is also known as a U-type centre-line flange butterfly valve. Where friction reduction or a longer service life is required, a double eccentric (double offset) version is available on request. When the body cavity, disc and all wetted internals are rubber lined, the valve is described as a fully rubber-lined flange end butterfly valve.

Flange End Butterfly Valve Solutions for Industrial Pipelines

When it comes to high-pressure sealing and long-term pipeline reliability, compromising on quality is never an option. As a certified China butterfly valve manufacturer, we deliver industrial-grade flange end butterfly valve systems engineered to perform in the world’s most demanding fluid control environments — from municipal water networks and HVAC plant rooms to heavy chemical processing — ensuring seamless operation and maximum safety.

Every butterfly valve flange end configuration we produce is precision machined to comply with strict international drilling standards, including ANSI, DIN and JIS. Robust bodies, heavy-duty stems and resilient or metal-to-metal seats guarantee zero-leakage performance, bubble-tight shutoff and minimal pressure drop. That construction lowers field maintenance costs and extends operational life under harsh conditions.

Why Choose Our Butterfly Flange Valve Products?

Factory-direct supply. Large-scale production capacity delivers premium China butterfly valve products at competitive wholesale pricing, protecting your project margin.
Engineered customisation. From body materials (ductile iron, WCB, SS316) to seat options (EPDM, Viton, PTFE) and non-standard flange drilling, every butterfly flange valve is built to your pressure and temperature data sheet.
Rigorous quality control. 100% shell and pressure tested before shipment, with material certificates and test reports available for project documentation.

Typical Applications and Use Cases

The flanged resilient seated butterfly valve is specified wherever a compact, low-torque isolation valve with a fully flanged, rigid connection is required. Typical service conditions include:

Municipal Water Supply

Distribution mains, pump stations, reservoirs and district metering areas. Epoxy-coated ductile iron bodies with EPDM seats suit buried and potable water service.

Water & Wastewater Treatment

Inlet works, aeration lines, sludge and backwash piping. Bi-directional sealing and a flush-through body avoid solids build-up.

HVAC & District Energy

Chilled water, condenser water, hot water and district heating/cooling networks, including modulating duty with electric actuators.

Chemical & Petrochemical

Dilute acid, alkali, brine and solvent lines. SS316 disc, PTFE seat and rubber-lined body options for corrosive media.

Power Generation

Circulating and cooling water, service water, FGD absorber and limestone slurry lines in thermal and biomass plants.

Mining & Slurry

Tailings, process water and thickener lines where abrasion-resistant seat compounds and heavy-duty stems are required.

Desalination & Marine

Sea water intake, RO feed and brine discharge. Aluminium bronze disc and SS316 stem resist chloride attack.

Food, Beverage & Paper

Process water, CIP lines and pulp stock systems, using food-grade EPDM or PTFE seats with polished wetted surfaces.

Materials of Construction

No.	Part Name	Material
1	Body	Carbon steel / stainless steel / cast iron / ductile iron / Al-bronze
2	Disc	Al-bronze / CF8M / ductile iron / WCB
3	Seat	EPDM / PTFE / Buna-N / NBR / Hypalon
4	Stem	Carbon steel / stainless steel 304 / stainless steel 316
5	Bushing	PTFE / self-lubricating
6	O-ring	EPDM / PTFE / Buna-N / NBR / Hypalon
7	Pin	SS316 / SS416 / SS304

Design, Connection and Testing Standards

Design & Manufacture	Flange Connection	Face to Face Dimension	Test & Inspection
MSS SP-67 API 609 EN 593	DIN PN10/16/25; ANSI B16.1 BS 4504; ISO PN10/16 JIS B2212/2213 BS 10 Table D; BS 10 Table E	API 609 ISO 5752 series 20 BS 5155	API 598

Flange End Butterfly Valve Dimensions (DN50 – DN2000)

All dimensions in millimetres. Ø = stem diameter, h = body height, n1-Ød1 = ISO 5211 top flange drilling, n-Ød = flange bolt holes, N-M = flange thread. Values in brackets are alternative drilling patterns — please confirm on order.

DN (mm)	A	B	L	Flange No.	ØE	ØF	n1-Ød1	Ø	h	PN10				PN16
DN (mm)	A	B	L	Flange No.	ØE	ØF	n1-Ød1	Ø	h	ØD	ØD1	n-Ød	N-M	ØD	ØD1	n-Ød	N-M
50	136	75	43	F05	65	50	(4-8)	12.6	32	165	125	(4-18)	4-M16	165	125	(4-18)	4-M16
65	139	83	46	F05	65	50	(4-8)	12.6	32	185	145	(8-18)	8-M16	185	145	(8-18)	8-M16
80	155	97	46	F05	65	50	(4-8)	12.6	32	200	160	(8-18)	8-M16	200	160	(8-18)	8-M16
100	169	109	52	F07	90	70	(4-10)	15.77	32	220	180	(8-18)	8-M16	220	180	(8-18)	8-M16
125	183	125	56	F07	90	70	(4-10)	18.92	32	250	210	(8-18)	8-M16	250	210	(8-18)	8-M16
150	198	139	56	F07	90	70	(4-10)	18.92	32	285	240	(8-22)	8-M20	285	240	(8-22)	8-M20
200	235	172	60	F10	125	102	(4-12)	22.1	45	340	295	(8-22)	8-M20	340	295	(12-22)	12-M20
250	267	207	68	F10	125	102	(4-12)	28.5	45	395	350	(12-22)	12-M20	405	355	(12-26)	12-M24
300	305	238	78	F10	125	102	(4-12)	31.7	45	445	400	(12-22)	12-M20	460	410	(12-26)	12-M24
350	336	265	78	F10	125	102	(4-12)	31.7	45	505	460	16-22	16-M20	520	470	16-26	16-M24
400	304	86	86	F14	175	140	(4-18)	33.15	52	565	515	16-26	16-M24	580	525	16-30	16-M28
450	411	337	105	F14	175	140	(4-18)	38	52	615	565	20-26	20-M24	640	585	20-30	20-M28
500	460	368	127	F14	175	140	(4-18)	41.15	64	670	620	20-26	20-M24	715	650	20-33	20-M30
550	500	400	154	F16	210	165	(4-22)	50.65	70	730	675	20-30	20-M27	775	710	20-33	20-M30
600	523	428	154	F16	210	165	(4-22)	50.65	70	780	725	20-30	20-M27	800	770	20-36	20-M33
650	541	480	165	F25	300	254	(8-18)	63.35	95	835	780	24-30	24-M27	860	790	20-36	20-M33
700	595	510	165	F25	300	254	(8-18)	63.35	95	895	840	24-30	24-M27	910	840	24-36	24-M33
750	642	541	165	F25	300	254	(8-18)	63.35	95	965	900	24-33	24-M30	970	900	24-36	24-M36
800	662	580	190	F25	300	254	(8-18)	63.35	95	1015	950	24-33	24-M30	1025	950	24-39	24-M36
900	772	635	203	F25	300	254	(8-18)	75	130	1115	1050	28-33	28-M30	1125	1050	28-39	28-M36
1000	820	705	216	F25	300	254	(8-18)	85	130	1230	1160	28-36	28-M33	1255	1170	28-42	28-M39
1100	858	763	254	F25	300	254	(8-18)	85	130	1340	1270	32-36	32-M33	1355	1270	28-42	28-M39
1200	942	846	254	F30	350	298	(8-22)	105	150	1455	1380	32-39	32-M36	1485	1390	32-48	32-M45
1400	1000	900	279	F35	415	356	(8-32)	120	150	1675	1590	36-42	36-M39	1685	1590	36-48	36-M45
1600	1150	1102	318	F35	415	356	(8-32)	140	200	1915	1820	40-48	40-M45	1930	1820	40-56	40-M52
1800	1260	1156	356	F40	475	406	(8-40)	160	280	2115	2020	44-48	44-M45	2130	2020	44-56	44-M52
2000	1363	1350	406	F40	475	406	(8-40)	160	280	2325	2230	48-48	48-M45	2345	2230	48-62	48-M56

Actuation and Available Options

Hand Lever

Lockable 10-position lever with a notch plate for throttling. Standard on DN50 – DN200; ideal for infrequent manual operation.

Worm Gearbox

Self-locking gear operator with handwheel, reducing torque by 1/20 to 1/60. Recommended from DN200 upward or for high-pressure duty.

Electric Actuator

On/off or modulating 4-20 mA control, 220 V / 380 V / 24 V, IP67 enclosure, with limit switches and manual override.

Pneumatic Actuator

Double-acting or spring-return, 3–8 bar air supply, with solenoid valve, limit switch box and air filter regulator.

Other options: extended stem for buried service, chain wheel, stem extension with floor stand, positioner, stainless steel nameplate, third-party inspection and non-standard flange drilling.

Product Show

Double flange butterfly valve with worm gear operator, PN16

Worm gear operated flange end butterfly valve

Resilient seated butterfly valve flange end, EPDM seat and ductile iron body

Resilient seated body and disc assembly

China butterfly valve manufacturer factory supply flange end butterfly valve

Epoxy coated body, ISO 5211 top flange

Frequently Asked Questions

What is the difference between a flange end butterfly valve and a wafer butterfly valve?

A flange end (double flange) butterfly valve has its own flanges and bolts to both pipe flanges, so the pipeline stays rigid and the valve can be removed without pulling the pipes apart. A wafer valve is clamped between two flanges with long through-bolts and needs no gaskets, but provides less structural support. For buried lines, high-pressure service or end-of-line duty, the flanged version is preferred.

Which seat material should I choose — EPDM, NBR, PTFE or Hypalon?

EPDM is the general-purpose choice for water, hot water and steam up to about 120°C. NBR (Buna-N) suits oil, grease and fuel service. PTFE is selected for acids, solvents and temperatures up to 150°C. Hypalon offers good resistance to oxidizing chemicals and abrasion. Please share the medium, concentration and temperature and we will confirm the compound.

Can the valve be used for throttling and modulating control?

Yes. The flow characteristic is close to linear and the disc can be held at any intermediate angle. For continuous modulating duty, specify a worm gearbox or a modulating electric actuator rather than a hand lever, and avoid throttling in the first 15° of travel where cavitation risk is highest.

Do you supply sizes above DN1200?

Yes. The standard range runs from DN50 to DN2000 (2" to 80"), with PN10 and PN16 drilling as standard. Larger diameters in PN10 up to DN2000 are routinely produced; please send your dimensional and pressure requirements for a project-specific quotation.

What testing and documentation is provided?

Every valve is shell tested at 1.5 times the rated pressure and seat tested at 1.1 times, to API 598. On request we supply material certificates (EN 10204 3.1), dimensional reports, epoxy coating thickness reports, and third-party inspection such as SGS or BV.

Can you produce valves under our own brand?

Yes. OEM and ODM service is available: custom nameplate, customer colour, private-label packaging, custom flange drilling and special face-to-face dimensions. Typical lead time is 15–25 days for standard sizes and 25–35 days for large diameters or actuated assemblies.

Packing, Delivery and Service

Packing

Each valve protected by a plastic cap on both flange faces
Plywood case or pallet, seaworthy export packing
Desiccant and VCI film for long sea transit
Customary marks and shipping marks per customer request

Service

Drawing and data sheet confirmation before production
Pre-shipment photo and test report package
Spare seat, O-ring and bushing kits available
Technical support on installation, torque and actuator sizing

Need a flange end butterfly valve quotation?

Send us your size, pressure rating, medium, temperature and flange standard. Our engineering team will confirm the model, seat compound and actuator sizing, and reply with a formal quotation within one working day.

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