Structural principle

The three valve group is composed of a valve body, two cut-off valves and a balancing valve. Zero pressure online transmitter zero check operation procedure: first, turn on the balance valve and close the two stop valves.

Zero check for transmitter. The three valve group can be matched with 3051, 3095, 1151, EJA, FX-2, FCX-A/C and ST3000 series differential pressure transmitters.

Main function

It is necessary to use balance valve when installing and removing. Otherwise, the range of differential pressure is generally very small. If the overload capacity of the manufacturer is not strong, it is easy to damage.

A simple example: if the differential pressure is 60KPa and the pipe pressure is 1MPa, if there is no balancing valve, no matter whether the positive pressure chamber or negative pressure chamber is first taken, it will immediately lead to the differential pressure of both sides far exceeding the set value. Because the first party will directly communicate with the atmosphere, equivalent to 0.1MPa, so the operation is fatal.

Effect

When the flow or differential pressure sensor instrument is connected to the process pipeline, the "three valve group" shall be used.

1. When the pipeline is added from the initial state (empty), the pressure on both sides of the sensor will suddenly change. If the pressure difference is too large, the sensor of the transmitter may be damaged. To avoid this, the valve A and B on both sides of the sensor should be closed, and the bypass valve C should be opened.

2. When the medium is filled with pipes, after balancing, open one of the A or B, so that both sides of the sensor will exert pressure evenly.

3. Turn off the valve C and open another valve in A or B, and the sensor will start working normally.

4, the closing order is contrary to the above situation.

In addition, there are other functions of the 3 valve group. If the pipeline is cleaned after running for a period of time, the sensor part will not be affected (the pipeline is bypassed).