Regulating valve site inspection

The main performance testing an on-site control valve

Regulating valve comprehensive performance indicators, including many, in addition to some items before installing just check verification, test certificate products, the proposal should focus on the following items for testing and calibration.

1) Basic error: the input signal is 20 ~ 10kPa to increase or decrease the balance of the input actuator chamber (or locator), the measurement points corresponding to the stroke value, calculated as follows: - Relationship "signal traveling" and Each point error between the theoretical value, which is the maximum basic error. Test point signal range should include at least 0,25%, 50%, 75%, 100% this five points should be limited to the basic error of measuring instruments were tested Range Top Burner Valve a quarter of the basic error limit.
2) Backlash: Test methods with one. The maximum difference between positive and negative travel on the same input signal is the secret was hysteresis.
3) Always point deviation: Test methods with one. Limit signal (starting point) is the basic error at the starting point of deviation; basic error limit (end) at the end of the signal is the deviation.
4) Leakage: more easily test medium for room temperature water test pressure test a trial by A as follows: When the valve pressure is less than 350kPa, test pressure according to 350kPa do, when the valve is working by allowing the pressure differential is greater than 350kPa do; and B test a trial according to the maximum working pressure valves do. A test in a trial, the gas pressure to open the valve actuator signal is zero; gas closed valve actuator signal pressure to the upper limit of the input signal; B test in a trial, the signal pressure from the actuator should the value of the design requirements. Test media should be required to flow into the valve, the gas Burner Valves outlet connection can be directly connected to the outlet through the atmosphere or atmospheric low pressure loss measuring device to confirm the valve and downstream of the connecting pipe is completely filled with the media before taking measured leakage.
5) The main valve, extreme pressure test should be done.
6) for supporting the valve locator, transportation, installation process, it is easy to move the positioner feedback touch panels and touch loose gas fittings. Therefore, before installation, commissioning, should be on-site commissioning.

2 valve-site installation points to note

Focus on the following issues when adjusting the valve is installed:

1) First, it is safe. Valve (ie installation, testing, operation and maintenance) in all aspects of the operation of safety, attention to personnel and equipment.
2) Maintenance and accessibility valve manually operated, so that in the future the instrument into a more convenient on-site operation and maintenance.
3) Press the flow direction of the installation (if installed backwards, the valve will start to oscillate or jump phenomenon).
4) straight pipe before the valve as far as possible longer.
5) If possible, use the outlet pipe 3 to 5 times the pipe diameter of straight pipe.