Valve manifold is a standard accessory for pressure transmitter and differential pressure transmitter.
By providing a valve manifold in the instrument, it will allow a calibration or change the instrument without the necessity of plant shutdown.
In particular application there are three type of valve manifold, 2-way valve manifold, 3-way valve manifold, and 5-way valve manifold.
Pressure Transmitter 2 way Manifold
2-way valve manifold is used for pressure transmitter only. The typical 2-way valve manifold consists of 1 block valve and 1 drain or test valve.
If we want to calibrate the pressure transmitter, we just need simply close the block valve and open the drain valve.
Then connect the drain valve connection to the pressure generator to give some test pressure.
Pressure Transmitter 3 way Manifold
3-Valve Manifold is used for differential pressure transmitter. The typical 3-way valve manifold consists of 2 block valve and 1 equalizer valve.
If we want to check the zero of the differential pressure transmitter, we just need to close the block valve and open the equalizing valve.
This 3-valve manifold is rarely used in oil & gas industries especially in the offshore platform due to the un-available of test connection.
Some manufacturer have modified the 3-valve manifold by provide a plugged test connection, but in standard there is no test connection available.
Pressure Transmitter 5 way Manifold
Like 3-way valve manifold, 5-way valve manifold is also used for differential pressure transmitter. The typical 5-way valve manifold consist of 2 block valve, 1 equalizer valve, and 2 vent or test valve.
If we want to check the zero of the transmitter, we just need to close the block valve and open the equalizing valve. If we want to calibrate the transmitter for 3 or 5 point calibration, then after the pressure is equalized we just need to connect the test valve to a pressure generator.
This 5-way valve manifold is the most common valve manifold for differential pressure transmitter.
Manifold Hook up