- Gate valve
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- DIN f4 di flange resilient epdm gate valveDN450-1200 Resilient Seated Gate ValveDIN F5 Non-rising stem Resilient gate valveDIN F5 Socket connection soft seal gate valveUnderground cap soft seal gate valveBS5163 Rising stem Resilient soft seal gate valveBrass Threaded Gate ValveHard seal gate valveAPI Slab Gate ValveStainless Steel Gate ValveStainless Steel Knife Gate ValvePneumatic gate valve Control valveSoft Seal Gate ValveExtension stem gate valveNon rising stem Groove Soft Sealing Gate ValveRising stem Forged steel gate valveAPI carbon steel gate valveThreaded Gate ValveDin rising Stem And Non-Rising Stem Gate ValveUL-FM Rising stem flanged fire fighting system gate valveANSI Cast Iron Gate ValveBritish Standard Soft-Sealing Gate Valve
- Butterfly valve
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- DN2000 Double Eccentric Butterfly ValveFlange butterfly valveLug butterfly valveWafer Butterfly Valve With HandleWorm Gear Operated Wafer Butterfly ValveWafer lined fluorine butterfly valvestainless steel wafer butterfly valveStainless Steel Flanged Butterfly ValveEccentric soft sealing flange butterfly valveElectric three-eccentric metal hard seal butterfly valvePneumatic Flanged Butterfly ValvePneumatic Wafer Butterfly ValveThree eccentric metal seals wafer butterfly valveULC butterfly valve reportInflatable Butterfly ValveHigh Performance Butterfly ValveGrooved butterfly valvesElectric soft sealing wafer butterfly valveDouble flange fluorine lined butterfly valveHandle Aluminum Butterfly ValveWorm Gear Aluminum Butterfly ValveFull PTFE lined wafer butterfly valveOne stem no-pin wafer butterfly valveMulti standard Aluminum handle wafer butterfly valveMulti standard soft seat aluminum lever coated discwafer type butterfly valveResilient Seated Butterfly ValveMulti standard soft seat wafer type butterfly valveWafer PTFE seat butterfly valveWorm Gear Operated Lug Butterfly ValveStainless Steel wafer Butterfly ValvePneumatic Wafer Butterfly ValveWafer Type Metal Seat Butterfly ValveLug type manual wafer butterfly valve without pinAluminium Handle Lug Butterfly ValveWorm Gear Operated Flange Butterfly ValveLever Operated Flange Butterfly ValveButterfly valve stemButterfly valve discButterfly valve seat
- Ball valve
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- High platform flange ball valveCast Iron Ball ValveSS Thread Ball ValvesThree Piece Type Ball ValveAPI Ball ValveStainless Steel 3PC Ball ValvePTFE Seat Flanged Ball ValveForge Steel Fully Welded Ball ValveMetal Seat Ball Valvesfixed ball valveFlange connection ball valve3PC Type Ball Valve With Internal Thread Q11F/H-1000WOGThree Way Ball ValveANSI API Cast Steel And Stainless Steel Flange Ball valveTwo-PCS Type Thread Ball Valve
- Globe Valve
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- API Carbon Steel Globe ValveBellows Globe ValveStainless steel flange globe valveStainless steel thread S type globe valveStainless steel thread B type globe valveCast Steel Globe ValvePiston Globe ValveWCB Carbon Steel Globe Check Valveelectric motorized control stainless steel SS316 globe valveBrass Globe ValveCryogenic Globe valveHT200 Globe ValveThreaded Stainless Steel Globe ValveGG25 Globe ValveANSI API Cast Steel And Stainless Steel Globe valve
- Check valve
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- DN800 Slow Closing Check ValveDN800 Rubber Disc Check ValveButterfly Buffering Check Valvecheck valve with counter weightSilent Check ValveStainless Steel flange Check ValveSwing Check ValveSingle Chip Check Valve H74WStainless Steel Wafer Check ValveSwing Start Check ValveFoot check valveAPI Swing Check ValveWCB Swing Check ValveCheck ValveLifting Check ValveBottom ValveHammer Diminish Noises Check ValveWafer Check ValveDuctile Iron Check Valve
- Water Meter
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- Vertical Type Water MetersStainless steel threaded water meterPiston water meterPlastic water meterMore flow rotor dry water meterspiral vane flange water meterCI wotlman water meter with pulse outputLXCLG(R) Vertical removable element woltman cold (hot) water meterSingle flow rotor dry water meterPrepaid Token Water MeterElectromagnetic flowmeterRotary Piston Liquid Sealed Water MeterRotary Piston Liquid Sealed Water Meter
- Air valve
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- Double ball exhaust valveDoubleair Air Valve SaudiDoubleair Air Valve Southeast AsiaDoubleair Air Valve South AmericaDouble Air ValveThreaded Air ValveSingle Air ValveTriple Functions Air ValveAutomatic Air Release ValveAutomatic release valveAutomatic exhaust valveComposite Exhaust Air ValveBrass exhaust valveDouble Ball Air Valve
- Pipe Repair & Coupling
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- Flexible Multi-Function Pipe Coupling ZFJ-SSS Semi-Circle Pipe Repair Clamp SJW-HDuctile Iron Band Repair ClampStainless Steel Band Repair ClampDouble-Section Pipe Repair CouplingFolding Type Pipe RepairSingle-Section Multi-Function Pipe Coupling MF-SGear-Ring Type Multi-Function Pipe Coupling GR-SZBW Damping Corrugated Hose
- Dismantling Joint
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- VSSJAFC(CC2F) Detachable Flange Transmission JointVSSJA-2(B2F) Double Flange Limited Expansion JointVSSJA-1(BF) Single Flange Limited Expansion JointVSSJA(AF) Flange Loose Expansion JointJGD-B Threaded Rubber JointZBW Damping Corrugated HoseKXT-S Flexible Dual-Spherical Rubber JointKXT Rubber Soft JointFlange Adaptor
Definition and working principle of butterfly check valve
2019-11-06
What is a butterfly check valve?
The butterfly check valve or the double disc check valve overcomes the aperture and pressure drop limits of the oscillating and disc type check valves, and the flap of the swing check valve is divided into two and hinged in the middle. Thus, the two discs can only be swung in one direction, and the disc is pressed against the valve seat by a spring loaded on the hinge. In order to have a hinge in the center of the flow channel, a fixing pin should be installed on the outside, which will cause leakage of the valve. After the design is improved, it can be installed inside, and the fluid can be sealed inside the valve body without leaking to the outside (see schematic diagram).
In the above picture, the butterfly check valve is normally closed due to the force of the torsion spring. When the fluid is flowing forward, the pressure of the fluid causes the disc to rotate around the hinge and the valve opens. Once the fluid flow stops, the valve closes before reversing due to the action of the spring.
working principle
If the root of the disc will wear out the seat during normal operation, frequent switching of the butterfly check valve will quickly cause damage to the seat. To overcome this problem, the root of the disc is lifted when the valve is opened, and the disc only rotates around the hinge. Compared with other forms of check valves, butterfly check valves have many advantages: Butterfly check valves are not limited by the diameter, can achieve DN5400; pressure drop ratio through the check valve through other forms of check valves The pressure is much lower; it can be used to open lower pressures; the butterfly check valve can be installed in any position.
