We have been facing serious problems in two areas of our plant. One is in liquid HCL isolating valves, we have more than 50 valves on dry HCL service at very low temperature but every now and then, we face gland leakage issue. Second, in valves afetr furnace where at pressure around 25 bar and temp of 100 deg C, HCL, VCL, EDC is there where we would need class 6 isolating valve. Currently we have butterfly valves but afetr some time, valve doesnot islate the system mainly due to carbon deposition on seats.

Live loaded packing configuration is an arrangement which adjusts the gland position to provide optimal sealing pressure on the packing. Disc springs are usually adopted to achieve this goal.

All the leakage seat classes as per FCI 70-2 (included class VI) refer more properly to control valves than to isolating valves. For isolating valve you should focus your attention on API 598 and API specification 6D.

Forgot to mention butterfly valve manufacturers...Try: Tyco flow control(Vanessa valves), Cameron group (formerly CCV) (Orton), Tomoe valves. These are but three of them, the first two practically every working condition experience, as they have been around the longest.

MORE NEWS