Long-distance pipeline electric control valve introduction and fault analysis and treatment

[Abstract] control valve gate is to ensure the stable operation of the key, a comprehensive variety of factors within the control process. In this regard, the author based on the experience of practical projects, introduced the actual operation of the Limitok electric control valve, and its failure and solution to a brief analysis. For the original long-distance pipeline electric control valve operation control provide a reference.
Key words: long-distance pipeline; electric control valve; failure analysis; solution method CLC number: V257.2 Document code: A Article ID: 1009-914X (2017) 20-0038-01
The crude oil long-distance pipeline electric control mainly lies in adapting to the change of the objective environment in time, changing the pumping unit and the pipeline mode, and delivering the effective amount of transportation through the minimum capacity. In this regard, in order to achieve this goal, not only need to determine the adjustment programs and related parameters, but also need to focus on price adjustment valves and device selection.
First, the electric actuator analysis of the implementing agencies and the valve body is the main part of the regulator . Among them, the implementing agency's main role is: regulating valve pushing device according to the signal generated by the thrust generated by the valve stem displacement and thus promote the valve spool movement. Valve body components are mainly regulating valve adjustment links, full contact with the media, according to the spool valve adjustment throttle action to achieve the intended goal. Long-distance transmission lines usually use electric control valves, actuators are mainly Limitok electric control valves. Body member is a flat gate valve . The main reason for selecting electric actuators is that energy applications are more convenient, sensitive and fast in signal transmission, which can be used in more distant signal transmission and convenient for connection with computer systems. However, there are some deficiencies in such a device. For example, it can not be effectively used in a fire and explosion proof environment, has a complicated structure and has a large economic input.
(A) Limitok electric control valve analysis In the valve adjustment technology, the process of online monitoring only need to state button to the pointer position mode, and then use the control button to switch the valve control. The implementing agency can efficiently supply electricity and start on-site operations. If remote control is required, connect the control cable to the terminal and then adjust the remote mode of the status key to the cursor position. As a result, we can effectively achieve the two-bit limit operation and the whole process of dynamic adjustment. During the handwheel operation, it is also possible to put the status key at the STOP position, and then turn the manual lever to the downward direction and rotate the handwheel to complete the handwheel operation. During the second operation, the manual lever can automatically bounce.
(B) commissioning analysis Limitok electric control valve can be set through the infrared set torque, limit and related performance adjustment. The set-up is certified to be electrically adjustable in the hazardous area. All adjustments can be entered into the actuator storage device, the user can see all the features on the display; can continue to debug and then meet operational requirements.
Second, long-distance pipeline electric control valve failure analysis and processing Oil, natural gas wellhead device with electric valve nominal pressure level API2000psi, 3000psi, 5000psi, 10000psi, 15000psi, 20000ps; nominal diameter of DN46--228mm (113/16 in- -9in); temperature classes K (-60-182 ° C), L (-42-182 ° C), P (-29-182 ° C), R (room temperature), S (-18-166 ° C ), T (-18--196 ℃), U (-18--121 ℃), V (2--121 ℃); Material requirements for AA, BB, CC, DD, EE, FF, HH; Requirements according to 36K, 45K, 60K, 75K; product specifications PSL1 (product specification level 1), PSL2 (product specification level 2), PSL3 (product specification level 3), PSL4 (product specification level 4). Some work around the valve found that: the valve medium penetration problems, infiltration of the medium in the top of the valve in the dust cap leakage. In response to this problem, after solving the problem of residual oil, the actuator and the valve body are disassembled and the filler is replaced by handwheel. In this way, effectively solve the leakage problem.
(A) Analysis of the reasons for the failure of the electric valve control Combined with user feedback, multi-turn electric valve and part of the valve due to the choice of power parameters error caused by the phenomenon of failure. The wrong choice of valve electric parameters will result in two kinds of electric valve failure problems: First, due to the smaller output torque caused by the closed valve is difficult to control, or even motor damage. Second, due to the large output torque, when the electric device control failure prone to structural damage to the valve, especially multi-turn valve. In the actual application process, the output torque is large or small have a certain impact. The other devices will not be affected due to the small output torque damaging the motor itself. The larger torque will cause damage to the weak parts of the electric valve can not be effectively applied, resulting in the pipe system can not be carried out smoothly.
Therefore, the electric valve electric device model output speed should be given high priority, if the pipeline system can choose the lower output speed possible. This is primarily because it reduces drive motor power and reduces the possible impact of multi-turn valve spool seating.
(B) remote control signal inconsistent with the scene Because the design units, manufacturers lack of technical transfer and exchange, prone to design units on the valve electric device electronic control system design and manufacturer actual system deviation, and restrict the application of electric devices.
In response to this problem, several methods were designed: First, the design principle of the control unit of the design unit was distributed to the electric device manufacturer, and the manufacturer was required to produce it. Second, the manufacturer combined with the requirements to provide control theory and system design, confirmed by the design unit, and finally the manufacturer under the final confirmation program for production, thus avoiding the electrical control principles and system problems.
According to practical experience, the application of electric valve electric devices required to meet several requirements. First, the number of remote control contacts and status, whether the need for the middle of the valve contact signal, whether to reserve passive contact. Second, continuous valve position feedback signal mode. Third, the number of torque control switch contacts. Fourth, the scene control button mode. Fifth, whether the electrical control uses the overall situation, namely: electrical components such as AC contactor installed in the electric device. Sixth, the terminal number and terminal board with or without other requirements, to avoid electrical interface problems. When the effective temperature is reached, the motor control circuit will be cut off. The thermostat's own thermal capacity is small, and the time-limited features are based on the thermal capacity of the motor. This shows that this method has a certain degree of scientific effect is remarkable.
Conclusion Comprehensive analysis of the implementation of the device as a combination of automatic control system in the automatic control system, the main influence is to accept the signal from the regulator device, according to the characteristics of process piping to adjust the flow of media to achieve the required target. Of course, also includes other fault problems, such as: valve leakage, leakage reasons such as failure sentence. The author separately from: electric actuator analysis, long-distance pipeline electric control valve failure analysis and treatment of two aspects to ensure that the process medium in the production and delivery phase in the effective range.
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