Bubble Tight Shut Off Ball Valve

Bubble tight shut off, a phrase describing the sealing ability of a valve. During air pressure testing of a new valve in the closed position, leakage past the seats is collected and bubbled through water. To qualify as bubble-tight, no bubbles should be observed in a prescribed time.

There is no definition of tight shut off (TSO) with respect to valves in API 6D or ASME B16.34 and this is where the confusion arises. The valves offered are tight shut off without commenting on the leakage rates or the type of test conducted (low pressure or high pressure) or the testing medium(air or gas).

Relia ball valve meet the bubble tight shut off Class, no visible leakage are detected for hydro test and air test according to API 6D and API 598 for both soft seat and metal seated ball valves.

How to make the ball valve meeting bubble tight shut off? All the ball valves are designed by rich experience engineer, respect to the ball valve working condition, client request, material selection and machining art. The metal seated ball and seat are coated with stellite, hard Cr or tungsten carbide and lapped as mirror in result.