High Pressure Plumbing Connections for Validyne Pressure Transducers

How to make plumbing connections that allow you to remove the transducer safely, if necessary, without shutting down the entire plant.

ONE

If you will be using the transducer for gauge pressure measurement (PSIG) where one port is open to the atmosphere, install a simple shutoff valve in the line to the transducer. Cover the open port of a differential pressure transducer with a porous filter to prevent entry of dirt and dust; a plastic cap with a small hole or a wad of fine wire is sufficient.

TWO

If you will be using a differential pressure unit for measuring a low DP across an opening or filter at high static line pressure, this requires more extensive valving to place it into operation, and also to remove it without overpressure damage. Exposing the transducer to full static system pressure on one side and atmospheric pressure on the other side will result in damage to the sensing element. To avoid this, use a valve arrangement as shown below:

THREE

To pressurize the DP transducer safely, close the drain valve and open the bypass valve. Then open both shutoff valves so as to apply the pressure equally to both sides of the transducer. Finally, close the bypass valve.

FOUR

To depressurize the transducer, open the bypass valve, close the shutoff valves, and SLOWLY open the drain valve. Once the pressure has drained from the transducer or transmitter, its plumbing connections can be disconnected.

Valve manifolds for this purpose are available from commercial valve and fitting suppliers.