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Double Flange Butterfly Valve Manufacturer

Laux Valve is a professional manufacturer of Double Flange Butterfly Valves designed in accordance with ISO 5752 Series 13 . Our product range includes both Vulcanized Seat Butterfly Valves and Replaceable Seat Butterfly Valves , providing dependable shut-off and flow control for municipal water supply, water treatment, HVAC, fire protection, chemical processing, power generation, and industrial pipeline systems. Engineered for secure flange connections, low operating torque, and long service life, every valve is manufactured under strict ISO 9001 quality management standards and pressure tested before shipment.

Double Flange Butterfly Valve

Double Flange Butterfly Valve is a flagship heavy-duty soft-seal product from Laux Valve, a professional valve manufacturer founded in 2011. This vulcanized seat butterfly valve ranges DN50–DN2400 (2"–96"), fully compliant with EN593, API609 and ISO5211 international standards.

It supports PN10/PN16/Class125/150 pressure grades, with DIN558-1 Series 13 standard face-to-face length and 16Bar maximum working pressure. All raw materials follow ASTM specifications, including ductile iron, stainless steel, duplex steel bodies and multi-type rubber seats (EPDM/NBR/FKM).

The double full-flange design provides excellent rigidity for municipal water, chemical and large-bore industrial pipelines. Custom material, dimension and actuator solutions are available for global buyers.

DN600 EN 558-1 Series 13 Double Flange Butterfly Valve with Epoxy Coated Disc

Concentric Double Flange Butterfly Valve Full Al-Bronze (C95800) Body & Disc – Seawater Service

Double Flange Butterfly Valve – Vulcanized Seat, Bi-Directional Dead-End Service

36" Double Flange Butterfly Valve — Ductile Iron Body, CF8M Disc, Gear Operated

DN700 Double Flange Butterfly Valve — Pneumatic Actuator & Nylon Coated Disc

Class250 AWWA C504 Flat Face AWWA C504 Double Flange Butterfly Valve

Concentric Flange Butterfly Valve

What Is a Double Flange Butterfly Valve?

A Double Flange Butterfly Valveis a resilient seated quarter-turn valve featuring integral flanges on both sides of the body, providing a rigid and secure connection to pipeline flanges. Compared with wafer and lug butterfly valves, the double flange design offers greater structural stability, making it especially suitable for large-diameter pipelines, underground installations, pump stations, and municipal water transmission projects.

Vulcanized Seat

Permanently bonded to the valve body for superior sealing reliability and long-term durability.

Replaceable Sea

Designed for easy maintenance and economical seat replacement without replacing the entire valve.

Manufactured according toISO 5752 Series 13 , our valves are available with multiple body, disc, shaft, and seat material combinations to suit a wide range of operating media, temperatures, and pressures.

Double Flange Butterfly Valve Features

Heavy-Duty Double Flange Body Design

The integraldouble flange bodyprovides exceptional structural strength and installation stability compared with wafer-style butterfly valves. Each flange is cast as part of the valve body, ensuring accurate alignment with pipeline flanges and reducing stress during installation. This robust construction is particularly suitable forlarge-diameter pipelines , pump stations, buried pipelines, and high-flow water transmission systems. The design also supports heavy manual gear operators, pneumatic actuators, and electric actuators without affecting valve performance or sealing

Optimized Low Torque Operation Double Flange Butterfly Valve

The streamlined disc profile minimizes flow resistance and operating torque, allowing smooth valve operation with manual levers, gearboxes, pneumatic actuators, or electric actuators. Lower torque not only reduces actuator size and energy consumption but also extends the service life of valve components by minimizing mechanical stress during opening and closing cycles.

Wide Material Selection for Different Media

Different industrial applications require different material combinations. Laux Valve provides a wide selection of body, disc, shaft, and seat materials to meet requirements ranging from potable water to aggressive chemical service. Available body materials includeDuctile Iron, WCB Carbon Steel, CF8, CF8M, and Aluminum Bronze . Disc materials includeNickel-Plated DI, Stainless Steel, Duplex Stainless Steel, PTFE-Lined, and Nylon-Coatedoptions, while shaft materials includeSS420, SS316, 17-4PH, and Duplex Stainless Steel . This flexibility enables customers to optimize both performance and cost.

Designed for Long-Term Industrial Service

Built with premium materials, precision engineering, and durable protective coatings, Laux Double Flange Butterfly Valves are designed for years of reliable operation in demanding industrial environments. Whether installed in municipal water networks, desalination plants, chemical processing facilities, or power stations, the valves provide dependable shut-off performance with minimal maintenance. The combination of robust construction, optimized sealing, and flexible material options makes them an ideal choice for customers seeking long service life and low total cost of ownership.

Vulcanized Seat VS Replaceable Seat for Double Flange Butterfly Valve

One of the biggest advantages of Laux Double Flange Butterfly Valves is the availability of two different seat structures to match different pipeline working conditions and maintenance demands.

Vulcanized Seat

The rubber seat is permanently vulcanized to the valve body during manufacturing. This construction eliminates seat movement and provides excellent sealing integrity throughout the valve's service life.

Advantages

Superior sealing performance
No seat displacement
Lower operating torque
Longer service life
Excellent for buried pipelines
Reduced maintenance

Recommended Applications

Municipal water
Water treatment
HVAC systems
Fire protection
Pump stations

Replaceable Seat

The replaceable seat is mechanically retained inside the valve body and can be replaced without changing the complete valve. This significantly reduces maintenance costs while extending the service life of the valve.

Advantages

Easy seat replacement
Lower maintenance cost
Shorter downtime
Flexible material selection
Better for industrial maintenance

Recommended Applications

Chemical plants
Industrial process lines
Power stations
Marine pipeline
Mining system

Butterfly Valve Technical Specification

1. Basic Parameter

Size Range	DN50 - DN2400 (2" - 96")
Design Standard	EN593, API609, BS5155, EN1092, ISO5211
Flange End Standard	PN10, PN16, Class125 / Class150
Working Pressure	DN50-DN300: 16Bar; DN350-DN2400: 10Bar
Face to Face Standard	DIN558-1 Series 13, ISO5752 Series 13
Test Standard	EN 12266-1, ISO5208, API598
Top Flange	ISO5211 Standard
Seat Type	Vulcanized Seat

2. Material Specification

Spare Part	Optional Material	ASTM Standard
Body	Ductile Iron	A536Gr.65-45-12
Body	Stainless Steel	A351 CF8 / CF8M
Disc	Plated Ductile Iron	A536 Gr.65-45-12
	Bronze	B148 C95400 / C95800
	Stainless Steel	A351 CF8 / CF8M
	Duplex Stainless Steel	A182-F15 / A182-F53 / A182-F55
Shaft	Stainless Steel	A276-410 / 304 / 316
Seat	EPDM, NBR, FKM(Viton)	-
Bushing	FRP, PTFE, Bronze	-
O-Ring	NBR, EPDM, Viton	-

3. Dimension Drawing Area

Figure: Overall Outline Dimension Drawing

4. Overall Dimension Table

✳Other Special Material and Dimension Requested, Pls Contact us Directly

DN(mm)	50 2"	65 2-1/2"	80 3"	100 4"	125 5"	150 6"	200 8"	250 10"	300 12"	350 14"	400 16"	450 18"	500 20"
A	110	134	131	150	170	180	210	245	276	328	376	407	433
B	80	80	95	114	114	139	175	203	242	250	310	332	358
C	108	112	114	127	140	140	152	165	178	190	216	222	292
W	26	30	30	30	30	40	40	40	40	40	50	70	80

DN(mm)	600 24"	700 28"	800 32"	900 36"	1000 40"	1200 48"	1300 52"	1400 56"	1600 64"	1800 72"	2000 80"	2200 88"	2400 96"
A	508	560	620	692	735	917	985	1000	1150	1200	1360	1500	1610
B	423	479	533	602	656	781	925	925	1041	1156	1350	1430	1650
C	267	292	318	330	410	470	490	530	600	670	760	800	850
W	80	80	85	95	118	118	118	154	200	200	200	300	300

www.lauxvalve.com

Professional OEM Butterfly Valve Manufacturer & Custom Solution

Valve Body Materials

Material	Description	Recommended Applications
Ductile Iron (DI)	Economical with excellent strength and durability for general service.	Water treatment, municipal water, HVAC, fire protection
Carbon Steel (WCB)	High mechanical strength for elevated pressure and temperature applications.	Oil & gas, petrochemical, power generation
CF8 (SS304)	Good corrosion resistance for clean water and mildly corrosive media.	Food processing, industrial water, general chemical service
CF8M (SS316)	Superior corrosion resistance against chlorides and aggressive chemicals.	Chemical processing, marine, pharmaceutical
Aluminum Bronze	Excellent resistance to seawater corrosion, cavitation, and erosion.	Marine, desalination, offshore, seawater cooling systems

Valve Disc Materials

Material	Description	Recommended Applications
Plated Ductile Iron	Cost-effective with enhanced corrosion resistance for general service.	Municipal water, HVAC, irrigation
CF8 (SS304)	Reliable corrosion resistance for potable water and industrial applications.	Water treatment, food & beverage
CF8M (SS316)	Excellent resistance to seawater, chlorides, and chemical media.	Chemical processing, marine, pharmaceutical
Duplex Stainless Steel	High strength with exceptional resistance to pitting and stress corrosion.	Offshore, desalination, chemical plants
Aluminum Bronze	Outstanding wear resistance and excellent performance in seawater.	Marine engineering, shipbuilding
Nylon Coated Disc	Low-friction coating with improved wear and corrosion resistance.	Water supply, HVAC, general industrial service
PTFE Lined Disc	Provides superior protection against highly corrosive chemicals and aggressive media.	Chemical processing, acids, alkalis, pharmaceutical

Valve Shaft Materials

Material	Description	Recommended Applications
SS420	High strength and hardness with excellent wear resistance.	General industrial, water treatment, HVAC
SS316	Superior corrosion resistance for aggressive media and seawater service.	Chemical processing, marine, desalination
17-4PH Stainless Steel	High tensile strength and excellent fatigue resistance for demanding applications.	High-pressure systems, automated valves, power generation
Duplex Stainless Steel	Combines high mechanical strength with exceptional corrosion resistance.	Offshore, seawater, chemical and mining industries

Material Selection Recommendation

Laux Valve offers multiple body, disc, and shaft material combinations to meet different media, temperatures, pressures, and environmental conditions. Our engineering team can recommend the optimal material configuration for your specific application, ensuring reliable sealing, extended service life, and cost-effective performance.

Butterfly Valve Flow Coefficient Kv & Pressure Drop Reference Data

All concentric lug butterfly valves and wafer butterfly valves are equipped with complete opening-angle Kv flow coefficient table and GPM-PSI pressure drop nomograph, supporting metric & imperial dual-system pipeline design calculation for global industrial projects. Flow coefficient Kv represents the fluid throughput capacity of the valve; higher Kv value brings lower pipeline pressure loss and less operation energy consumption.

1. Kv Value Table at Different Opening Angle (DN50 ~ DN600, 10°~90° Full Open)

DN	10°	20°	30°	40°	50°	60°	70°	80°	90° Full Open
50	0.1	5	12	24	45	64	90	125	135
65	0.2	8	20	37	65	98	144	204	220
80	0.3	12	22	39	70	116	183	275	302
100	0.5	17	36	78	139	230	364	546	600
125	0.8	29	61	133	237	392	620	930	1022
150	2	45	95	205	366	605	958	1437	1579
200	3	89	188	408	727	1202	1903	2854	3136
250	4	151	320	694	1237	2047	3240	4859	5340
300	5	234	495	1072	1911	3162	5005	7507	8250
350	6	338	715	1549	2761	4568	7230	10844	11917
400	8	464	983	2130	3797	6282	9942	14913	16388
450	11	615	1302	2822	5028	8320	13168	19752	21705
500	14	791	1674	3628	6465	10698	16931	25396	27908
600	24	1222	2587	5605	9989	16528	26157	39236	43116

Table Instruction: Small opening 10°~30° for precise flow throttling; medium opening 40°~70° for circulating water regulation; 90° full open delivers maximum Kv value with minimum flow resistance for main pipeline isolation.

2. GPM & PSI Pressure Drop Nomograph Chart

Figure 1: Flow Rate & Pressure Drop Nomograph for Concentric Butterfly Valve

The pressure drop curve chart adopts US imperial units, with horizontal axis for flow rate GPM and vertical axis for differential pressure (PSI / Feet water head). Diagonal slant lines correspond to matching Kv/Cv flow coefficients, helping North American and ANSI standard clients quickly calculate pipeline medium pressure loss.

Horizontal axis: Flow range 100 ~ 100,000 Gallons Per Minute, covers DN50~DN600 full size flow demand;
Vertical axis dual units: PSI pressure difference and Feet water head, convenient for direct conversion of pipeline design parameters;
Operation logic: Locate flow GPM vertically intersect Kv diagonal line, horizontally read pressure drop value to judge system energy loss.

3. Combined Application of Kv Table & Pressure Drop Curve

Step 1: Confirm working opening angle (throttling / full open), extract Kv value from the table;
Step 2: Convert metric Kv to US Cv via formula: Cv = Kv × 1.156;
Step 3: Match Cv diagonal line on the GPM-PSI nomograph, calculate actual pipeline differential pressure;
Step 4: If pressure drop exceeds design allowable value, upgrade to larger DN butterfly valve to raise overall Kv flow capacity.

Catalog Technical Tips

Kv test standard: Clean water 15°C, SG=1, comply with EN 12266-1 & ISO5211;
Avoid long-term stable operation under 10°~20° small opening, high pressure drop will cause cavitation and seal abrasion;
The pressure drop nomograph only applies to liquid medium; gas & steam flow calculation requires special gas coefficient formula;
We provide dual system flow data to meet metric European projects and imperial US standard engineering selection demands.

Manufacturing Excellence

Quality Control

Certification Quality Standard

100% Pressure Tested API598 ISO9001 CE WRAS ACS

LAUX Valve is a trusted OEM butterfly valve manufacturer, delivering customized valve solutions with reliable quality and global service.

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Butterfly Valve: Wafer Butterfly Valve; Lug Butterfly Valve; Double Flange Butterfly Valve; PTFE Lined Butterfly Valve; U-section Butterfly Valve; Grooved End Butterfly Valve; AWWA C504 Rubber Seated Butterfly Valve; Double Eccentric Flange Butterfly Valve

Knowledge Center: Butterfly Valve Basics; Butterfly Valve Material; Valve International Standards; Valve Selection Guide

No.3 Street,Beizhakou Town,Jinnan District,Tianjin.China

james@lauxvalve.com

+86 18920833829

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DN(mm)	50 2"	65 2-1/2"	80 3"	100 4"	125 5"	150 6"	200 8"	250 10"	300 12"	350 14"	400 16"	450 18"	500 20"
A	110	134	131	150	170	180	210	245	276	328	376	407	433
B	80	80	95	114	114	139	175	203	242	250	310	332	358
C	108	112	114	127	140	140	152	165	178	190	216	222	292
W	26	30	30	30	30	40	40	40	40	40	50	70	80

DN(mm)	50 2"	65 2-1/2"	80 3"	100 4"	125 5"	150 6"	200 8"	250 10"	300 12"	350 14"	400 16"	450 18"	500 20"
A	110	134	131	150	170	180	210	245	276	328	376	407	433
B	80	80	95	114	114	139	175	203	242	250	310	332	358
C	108	112	114	127	140	140	152	165	178	190	216	222	292
W	26	30	30	30	30	40	40	40	40	40	50	70	80

DN(mm)	50 2"	65 2-1/2"	80 3"	100 4"	125 5"	150 6"	200 8"	250 10"	300 12"	350 14"	400 16"	450 18"	500 20"
A	110	134	131	150	170	180	210	245	276	328	376	407	433
B	80	80	95	114	114	139	175	203	242	250	310	332	358
C	108	112	114	127	140	140	152	165	178	190	216	222	292
W	26	30	30	30	30	40	40	40	40	40	50	70	80