Abstract: The valve drive device is a device that uses external power to open and close the valve, and is one of the key equipments that are indispensable for automatic control of the station and pipeline. According to the use and use of the valve, several types of driving devices: manual device, pneumatic device, hydraulic device, electric device, gas-liquid linkage device and electro-hydraulic linkage device. In this paper, the faults of various valve driving devices used in a gas field are sorted and sorted, the causes of the faults are summarized, and suggestions for improvement are proposed from the aspects of design, installation and maintenance management.
Key words: drive unit; electric actuator; pneumatic actuator; gas-liquid linkage actuator 1 Introduction Valve drive device is a device that uses external power to open and close the valve. The purpose of the valve is to make the operation of the valve labor-saving, convenient, fast and reliable, or to achieve automatic control and remote control. The basic requirements of the valve drive device are: the torque or thrust can meet the opening and closing requirements of the valve, the control of the stroke and torque is accurate and reliable, the power selection is suitable for the site situation, the opening and closing action meets the control requirements, and the device itself is light and small. With the enlargement of the valve and the automation of the production process, in addition to the manual device, the most used ones are pneumatic devices, hydraulic devices, electric devices, gas-liquid linkage devices, and electro-hydraulic linkage devices.
2 Common driving device and fault analysis in a gas field 2.1 Electric actuator The electric actuator is a device that drives the valve by linear or rotary motion with a motor driven deceleration mechanism. It is characterized by small size, large torque output, high safety and reliability, suitable for remote control. And the need for automatic control is more widely used. Generally, it consists of a dedicated motor, a speed reduction mechanism, a remote control mechanism, a manual, an electric switching mechanism, and an opening indicator.
As of 2017, a gas field is using 447 electric actuators. The main brands used are LIMITORQUE, ROTORK and BIFFI. The problems are as shown in Table 1.
Analysis of the cause of the failure:
1 The component pins on the circuit board are oxidized, the circuit board itself is solidified due to material and temperature changes, and the line on the upper side is disconnected, which may cause malfunction of the electronic product. 2 Product selection: the product power is too small, the operating torque cannot be Meet the valve start-up requirements; the product withstand voltage range is too narrow, can not meet the objective use requirements of the gas field station in special areas such as townships; 3 product manufacturing: individual product manufacturing accuracy can not meet the requirements, the seal is not strict; 4 on-site operation staff Operational use, maintenance, and general troubleshooting skills of the equipment have yet to be improved.
2.2 Pneumatic Actuators Pneumatic actuators are mostly composed of pressure cylinders driven by compressed gas. It is characterized by compact structure, rapid opening and closing, suitable for indoor or corrosive, flammable and explosive environment; its disadvantage is that the piping is more complicated and not suitable for remote control.
As of 2017, a gas field is using 40 pneumatic actuators. The main brands used are ROTORK, BIFFI and BETTIS. It is mainly used as a driving device for emergency venting valves for field station ESD systems. This kind of equipment generally only operates during debugging. The main cause of failure is the aging of accessories caused by long service time.
2.3 Gas-liquid linkage actuator The gas-liquid linkage actuator is mainly composed of the poppet valve control block, manual pump device, actuator, gas-liquid tank, spare gas source tank, limit switch, LINEGUARD control box and so on. It is characterized by quick action and large output, which can drive large diameter valves.
As of 2017, a gas field is using 110 gas-liquid linkage actuators. The main brands used are BIFFI and SHAFER. Most of the equipment is located in the line valve room, and the running performance is relatively stable.
Analysis of the main causes of equipment failure:
1 In the in-service time, the aging of some seals of the gas-liquid linkage actuator is affected by the temperament, and the fault occurs when the controller cross-link gas causes malfunction, and the ball valve cannot open normally after closing the valve; 2 pneumatic control part seal More, high sealing requirements; some through holes are small, sensitive to particles and dust impurities, easy to block.
3 Improvement Suggestion 1 For aging, oxidation and easy-to-block components, store spare parts and perform targeted maintenance and troubleshooting training for site staff to ensure timely disposal of on-site problems; At the beginning, the technical specifications were reviewed, the goods inspected and inspected, and the on-site installation and joint testing were carried out to ensure that the product quality met the site requirements and installation specifications.
references:
[1] Zhou Xiangbin, He Jing et al. Research on troubleshooting and maintenance of electric actuators [J]. China Petroleum and Chemical Industry Standards and Quality, 2013 (6): 247.
[2]YANG Riyong, KANG Liang, PENG Zhenhua. Discussion on the maintenance of SHAFER gas-liquid linkage actuator[J]. Friends of Science, 2010(3): 26-28.
About the Author:
Li Bo (1976-), male, Han nationality, Sichuan Weiyuan people, senior gas transport workers, mainly engaged in natural gas pipeline transportation.
Key words: drive unit; electric actuator; pneumatic actuator; gas-liquid linkage actuator 1 Introduction Valve drive device is a device that uses external power to open and close the valve. The purpose of the valve is to make the operation of the valve labor-saving, convenient, fast and reliable, or to achieve automatic control and remote control. The basic requirements of the valve drive device are: the torque or thrust can meet the opening and closing requirements of the valve, the control of the stroke and torque is accurate and reliable, the power selection is suitable for the site situation, the opening and closing action meets the control requirements, and the device itself is light and small. With the enlargement of the valve and the automation of the production process, in addition to the manual device, the most used ones are pneumatic devices, hydraulic devices, electric devices, gas-liquid linkage devices, and electro-hydraulic linkage devices.
2 Common driving device and fault analysis in a gas field 2.1 Electric actuator The electric actuator is a device that drives the valve by linear or rotary motion with a motor driven deceleration mechanism. It is characterized by small size, large torque output, high safety and reliability, suitable for remote control. And the need for automatic control is more widely used. Generally, it consists of a dedicated motor, a speed reduction mechanism, a remote control mechanism, a manual, an electric switching mechanism, and an opening indicator.
As of 2017, a gas field is using 447 electric actuators. The main brands used are LIMITORQUE, ROTORK and BIFFI. The problems are as shown in Table 1.
Analysis of the cause of the failure:
1 The component pins on the circuit board are oxidized, the circuit board itself is solidified due to material and temperature changes, and the line on the upper side is disconnected, which may cause malfunction of the electronic product. 2 Product selection: the product power is too small, the operating torque cannot be Meet the valve start-up requirements; the product withstand voltage range is too narrow, can not meet the objective use requirements of the gas field station in special areas such as townships; 3 product manufacturing: individual product manufacturing accuracy can not meet the requirements, the seal is not strict; 4 on-site operation staff Operational use, maintenance, and general troubleshooting skills of the equipment have yet to be improved.
2.2 Pneumatic Actuators Pneumatic actuators are mostly composed of pressure cylinders driven by compressed gas. It is characterized by compact structure, rapid opening and closing, suitable for indoor or corrosive, flammable and explosive environment; its disadvantage is that the piping is more complicated and not suitable for remote control.
As of 2017, a gas field is using 40 pneumatic actuators. The main brands used are ROTORK, BIFFI and BETTIS. It is mainly used as a driving device for emergency venting valves for field station ESD systems. This kind of equipment generally only operates during debugging. The main cause of failure is the aging of accessories caused by long service time.
2.3 Gas-liquid linkage actuator The gas-liquid linkage actuator is mainly composed of the poppet valve control block, manual pump device, actuator, gas-liquid tank, spare gas source tank, limit switch, LINEGUARD control box and so on. It is characterized by quick action and large output, which can drive large diameter valves.
As of 2017, a gas field is using 110 gas-liquid linkage actuators. The main brands used are BIFFI and SHAFER. Most of the equipment is located in the line valve room, and the running performance is relatively stable.
Analysis of the main causes of equipment failure:
1 In the in-service time, the aging of some seals of the gas-liquid linkage actuator is affected by the temperament, and the fault occurs when the controller cross-link gas causes malfunction, and the ball valve cannot open normally after closing the valve; 2 pneumatic control part seal More, high sealing requirements; some through holes are small, sensitive to particles and dust impurities, easy to block.
3 Improvement Suggestion 1 For aging, oxidation and easy-to-block components, store spare parts and perform targeted maintenance and troubleshooting training for site staff to ensure timely disposal of on-site problems; At the beginning, the technical specifications were reviewed, the goods inspected and inspected, and the on-site installation and joint testing were carried out to ensure that the product quality met the site requirements and installation specifications.
references:
[1] Zhou Xiangbin, He Jing et al. Research on troubleshooting and maintenance of electric actuators [J]. China Petroleum and Chemical Industry Standards and Quality, 2013 (6): 247.
[2]YANG Riyong, KANG Liang, PENG Zhenhua. Discussion on the maintenance of SHAFER gas-liquid linkage actuator[J]. Friends of Science, 2010(3): 26-28.
About the Author:
Li Bo (1976-), male, Han nationality, Sichuan Weiyuan people, senior gas transport workers, mainly engaged in natural gas pipeline transportation.
Hammer Union,Hammer Union Fittings,Industrial Hose Coupling,Industrial Hose Connector
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