The ball valves have cavity vents. In between the ball valves is a check valve. There is a small section (6" long) of piping at the end of "Valve 2", followed by a blind flange.

Find ball valves class 800 accordingly ANSI/ASME STD,STD Reference.ISO STD 17292 and BS 5351 cover the class 800# for all valves.

Talk about single block and bleed ball valve,With regards to single block and bleed valves, you can either install as two separate valves.

Performed passing test on MOV's on low pressure, we found valves passing, I would like to know if the high pressure above 60barg will seal the seat leakage.

The typical trim in small floating ball valves is Austenitic Stainless Steel (304 or 316); this is what is stocked and readily available.

A standard for allowable leak rates during ball valve testing,addressing shutoff valves (bubble tight) instead of control valves (which leak like a sieve).

Positive isolation can be obtained with the correct selection of valves. Use a DBB (double block and bleed) valve and you can have the isolation that is required.

Differences in ball valve design, especially with respect to Ball/Seat combinations in metal sealing applications.