General Questions & Answers

In what position should the ball valves be held during the hydrostatic test?

When performing hydrostatic testing of ball valves along with pipelines, the recommendations of the ball valve manufacturer should be followed.

In general, the pipeline system should be filled with water with the ball valves in 100% open position. Prior to testing, it is recommended that the system be flushed to remove all debris. During flushing, it is common practice to remove the valves and replace them with spool pieces to prevent damage to the valve seats from dirt and other construction debris carried along.

Ball valve

Once the piping is flushed and filled with water, before the system is pressurized, the ball valves are partially opened to prevent pressure differential between the valve body cavity and the piping system.

After the system is fully pressurized, the ball valves are inspected to ensure that they do not leak at the stem seal and other threaded connections.

Upon completion of the hydrotest, the valves should be returned to the fully open position. The valves should not be left in the partially open position for an extended period of time as this may cause damage to the elastomers in the seat ring and eventually cause leakage.

Detailed Information

Pressure gauges
Hydro Testing
Hydrostatic testing of pressure piping is a mandatory activity before finalization of any new or modified piping system. It is the final check of mechanical integrity of the whole system and should be followed religiously as after this activity the piping system has to be commissioned...

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