- 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
Safety Valve problem and solutions
2016-09-05
Improper selection or operation may result in faults to safety valves. If such faults are not corrected in time, they can have impact on the effect and life of valves, and even cause them unable to perform the function of safeguard. The table below shows the common faults and solutions.
Faults
Causes
Solutions
Leakage
1. Dirt Occurred on sealing surface
Use lift wrench or other method to make valve opened several times to wash away the dirt. If the dirt cannot be removed, take apart the valve to clean it away, and then have the valve reassembled for commissioning.
2. Sealing surface damaged
Take apart the valve and have the damage repaired by grinding or grinding after turning responding to the extent of damage. After repair, sealing face shall be assured of sound plainness With its roughness Ra value not lower than 0.1.
3. Improper installation or the additional load of pipeline
Re-install or remove the additional load of pipeline.
4. High temperature or corrosive media
Have spring or even valve replaced according to the actual working conditions. If it is merely for the reason of improper adjustment of spring, it can be regulated by fastening or loosening the adjusting bolt.
5. The opening pressure of safety valve is too close to the working pressure equipment
Reset the pressure with the permissible range of spring pressure. On the condition that strength can be met, the set pressure of safety valve shall be suitably enhanced.
Inflexible opening and closing
1. Improper position adjustment of adjusting ring
Improper position of adjusting ring has made the opening process of safety valve lengthened or re-seating slow. Re-adjust it to meet the requirements of production process
2. The moving parts inside jammed
It may be possibly for the reasons of improper assembly, insufficient machining precision, valve body invaded by impurities, or spare parts getting corroded. Take out solutions according to different occasions.
3. Excessive resistance of discharge pipe, high discharge back pressure, or insufficient lift of safety valve
Reduce the bending of discharge pipe and try to use straight pipe of diameter greater than outlet diameter.
Deviation of opening pressure value
1.Caused by working temperature
1.Pressure regulation under cold state for safety valves used under thermal state, loosen the nut of adjusting bolt and suitably fasten the adjusting bolt.
2.In case of improper model selection, such as safety valve for boilers in power station, the type carrying radiator may be used.
2. Caused by spring corrosion
Replace the spring. Under the conditions where media have the property of corrosion, spring used shall be wrapped by fluorine plastic on surface or safety valves with bellows isolation mechanism shall be used.
3. Caused by Variation of back pressure
In case that back pressure varies greatly, bellows safety valves with balanced back pressure shall be used.
4. Moving parts inside jammed
Check and remove
Chatter or flutter
1. Excessive discharge capacity of safety valve ( relative to the required discharge capacity)
Use safety valves of rated discharge as far as possible close to the required discharge of equipment
2. The diameter of inlet pipe being too small or having too much resistance
Make the inner diameter of inlet pipe not lower than the inlet diameter of safety valve or reduce the resistance of inlet pipe.
3. Excessive resistance of discharge pipe ( excessive discharge back pressure)
Lower the resistance of discharge pipe.
4. Improper adjustment of adjusting ring
Re-adjust the position of adjusting ring and reduce the excessive re-seating pressure
Excessive rigidity of spring
Use spring of lower rigidity.
Faults
Causes
Solutions
Leakage
1. Dirt Occurred on sealing surface
Use lift wrench or other method to make valve opened several times to wash away the dirt. If the dirt cannot be removed, take apart the valve to clean it away, and then have the valve reassembled for commissioning.
2. Sealing surface damaged
Take apart the valve and have the damage repaired by grinding or grinding after turning responding to the extent of damage. After repair, sealing face shall be assured of sound plainness With its roughness Ra value not lower than 0.1.
3. Improper installation or the additional load of pipeline
Re-install or remove the additional load of pipeline.
4. High temperature or corrosive media
Have spring or even valve replaced according to the actual working conditions. If it is merely for the reason of improper adjustment of spring, it can be regulated by fastening or loosening the adjusting bolt.
5. The opening pressure of safety valve is too close to the working pressure equipment
Reset the pressure with the permissible range of spring pressure. On the condition that strength can be met, the set pressure of safety valve shall be suitably enhanced.
Inflexible opening and closing
1. Improper position adjustment of adjusting ring
Improper position of adjusting ring has made the opening process of safety valve lengthened or re-seating slow. Re-adjust it to meet the requirements of production process
2. The moving parts inside jammed
It may be possibly for the reasons of improper assembly, insufficient machining precision, valve body invaded by impurities, or spare parts getting corroded. Take out solutions according to different occasions.
3. Excessive resistance of discharge pipe, high discharge back pressure, or insufficient lift of safety valve
Reduce the bending of discharge pipe and try to use straight pipe of diameter greater than outlet diameter.
Deviation of opening pressure value
1.Caused by working temperature
1.Pressure regulation under cold state for safety valves used under thermal state, loosen the nut of adjusting bolt and suitably fasten the adjusting bolt.
2.In case of improper model selection, such as safety valve for boilers in power station, the type carrying radiator may be used.
2. Caused by spring corrosion
Replace the spring. Under the conditions where media have the property of corrosion, spring used shall be wrapped by fluorine plastic on surface or safety valves with bellows isolation mechanism shall be used.
3. Caused by Variation of back pressure
In case that back pressure varies greatly, bellows safety valves with balanced back pressure shall be used.
4. Moving parts inside jammed
Check and remove
Chatter or flutter
1. Excessive discharge capacity of safety valve ( relative to the required discharge capacity)
Use safety valves of rated discharge as far as possible close to the required discharge of equipment
2. The diameter of inlet pipe being too small or having too much resistance
Make the inner diameter of inlet pipe not lower than the inlet diameter of safety valve or reduce the resistance of inlet pipe.
3. Excessive resistance of discharge pipe ( excessive discharge back pressure)
Lower the resistance of discharge pipe.
4. Improper adjustment of adjusting ring
Re-adjust the position of adjusting ring and reduce the excessive re-seating pressure
Excessive rigidity of spring
Use spring of lower rigidity.
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