Back Pressure Testing
Saving your from re clamping the valve
The only function of balanced bellows inside safety valves is to keep possible back pressure from flare lines away from the disk, ensuring a reliable set point at any time. If the bellow leaks the set point of the valve will alter along with the back pressure. Consequently, testing the bellows tightness is a standard task within the safety valves end test. A common method to do this is to tilt the safety valve, clamp its outlet flange to the test bench and supply low pressure into the outlet.
When frequently testing safety valves with bellows or to test safety valves with simulated back pressure, METRUS offers the option “back pressure testing” consisting of easy to mount sealing plates of different size plus a separate regulator and gauge for controlling the back pressure level.
To mount the sealing plate the pre levelled holder is set on the upper rim of the valves outlet flange, the two claws are slid together and tightened via the tension levers. Using the dedicated pressure control valve, the user adjusts the required back pressure level required. A dedicated on/off switch is available to turn the back pressure on whenever needed. Small safety valves are fitted to the larger sealing plates preventing the sealing plates from being burst off in case the operator charges too much back pressure accidentally.