CNG Tank Valve

CNG Tank Valve


Valve for CNG Cyinder, come with fittings connected to 6mm diameter steel line    RFQ

1) Suitable Medium: Compressed Nature Gas
2) Rated Working Pressure is 20Mpa=3000psi, although it can bear 25Mpa=3600psi.
All CNG kits in China are stated as "rated working pressure 3000psi", though they can bear 3600psi no problem.
3) Nominal Diameter: DN5mm
4) Outlet Joint thread: Female thread 2-NPT1/14
5) Joint thread to cylinder: GB8335PZ27.8
6) Safty device: 33±2Mpa, 110°C±5°C
7) Quality certificate: SQC certificate for quality management system,has complied with the requirements of GB/T 19001-2000 idt ISO 9001:2000 

Type No. Working pressure Nominal diameter Outlet joint thread Joint thread to cylinder Temp./Pressure of safety device
QF-T1 20 4 Internal thread 2-NPT1/4 PZ27.8 33±2Mpa,110°C±5°C
QF-T1A 20 4 Internal thread 2-NPT1/4 PZ27.8 27±3Mpa,110°C±5°C

CNG Cylinder valve.JPGTank valve diagram.jpg

General statement
The tank valve is a special device used in CNG tank to control gas out and in. working medium: CNG, working pressure 20MPa and 25MPa, working temperature -40℃~85℃.Twist anticlockwise 90 degree to open. When pressure 33±2Mpa, temperature 110°C ±5°C, the safety device will act automatically to release gas pressure.
Operating instruction and points for attention
1. Connect to the cylinder using tapered or straight threads. For a tapered thread, three or four sealing adhesive tapes shall be packed around thread surface, the wrenching torque shall be 250~300N.m for Pz27.8, Bs341-1”, 3/4-14NGT etc. tapered threads; For M25*2, 1.125-12UMF etc. straight threads, the wrenching torque shall be 80~150N.m; Wrenching torque for other thread sizes and types, please refer to above. 
2. While assembling joint to connect pipeline, a showing torque tool shall be used. The closing torque shall be strictly performed by the following rules. For a tapered thread which is sealed by conical surface, three or four sealing adhesive tapes shall be packed around thread surface. The closing torque shall be 30~40N.m for NPT 1/4. For a piped thread which is sealed by spherical surface, the closing torque shall be 35~45N.m for W21.8. For a straight thread which is sealed by flat surface, either M12 or M14, the closing torque shall be refer to above.
3. While assembling up pipeline to connect valve, tight force shall only be forced on the connectors or the parts connected with connectors. Don’t attempt to regard valve as supporters in order to tight the parts which connected with valve indirectly.
4. If it opens the valve by rotation this shall be in anticlockwise direction. Hand wheel or handle is operated by hands to open or close Valve. While opening or closing valve, don’t attempt to replace hand wheel or handle by any other tools. Operate slowly to open the valve. Don’t open or close it quickly.
5. In vehicle fuel system valve is a key component which easily damaged. In order to ensure safety, it shall be checked for leakage as follows.
5.1 Everyday before vehicle starts working;
5.2 When valve’s pressure is more than 26MPa or temperature is higher than 85℃;
5.3 Each time after filling fuel to cylinder;
5.4 After cylinder suffers severe vibration or collision by outside force;
5.5 Valve without effective ventilation shall be capable of being continuously operated for more then three hours in the hot weather. If it is unusual, lease maintain it without delay, especially if fusible alloy of pressure relief devices is squeezed out from its original position for 1mm, pressure relief devices shall be replaced without delay.
6.If valve has been performed an endurance test for 200,000 cycles and still can still can be used as normal, it proves that it is satisfied specification of related rules for one cylinder’s inspection period. Whereas influence of vehicles complex operation environment and any other undetermined factors the suggestion of completed inspection on safety shall be safety shall be carried out by one of the following three conditions:
6.1 Having driven a vehicle for one year;
6.2 Having continuously filled to vehicle for 2,000 times;
6.3 Having traveled for 200,000km.
7. Valves’ maintenance and parts’ replacement shall be performed by professional cylinder inspection body or our after-sale service department. Don’t attempt maintenance and replacement them without agreement. Don’t attempt maintenance and replacement them without agreement. Do not replace our company’s original parts by any other ones.
8. On principle any outlet part which directly connects with valve shall be booked from our company. If it is purchased from any other company, size and precision shall be fitted to the valve.
9. After a whole system having been connected, a leak tightness shall be performed after decompression, but the torque shall not be more than 1.25*T (T-intended torque). If failure still occurs, please check all packing surfaces. If it is damaged, please replace it. Don’t tight the valve with unlimited torque.
10. When the valve outlet pipeline had breakage and caused a lot of medium (gas) leakage, flow restrictor protection devices will play a role of flow control. The condition of the flow control is the pressure difference reaching 0.65MPa between the device outlet and inlet. The valve equipped with the flow restrictors protection device, should be open in a slight pause on the micro-open position. When the pipeline is filled with gas, slowly open the valve to its normal position. The valve should not be open quickly or it will cause the flow restrictor operating. If the overflow restrictor protection device operates and reduces the flow, the valve should be closed, and flow restrictors protection device will automatically reset within 30Sec.
11.If a valve equipped with protective device against leakage, a pipeline shall be used as a passage to connect protective device to a safety area. If a valve without protective device, a protective cap against leakage shall be equipped.
12.Refilling cylinder shall be complied with related standards. Vehicles shall be gone out fire and out off electric power supply. Don’t fill a cylinder by excessive speed, pressure or temperature.
13.During exchange and service period, valve shall be avoided influence by moisture, high temperature and corrosive. Don’t permit to suffer any damage from external force, such as fall or striking.
14.The valve internal shall be cleaned (sweeping and replacement) periodically because of CNG gas cleanness, to prevent the contaminants make effect on sealing, excess flow valve spring and make passages dead.

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