Ball valve leaving factory qualified but on-site leakage often due to installation stress leads to valve body deformation >0.3mm, actuator torque amplified 20% damages seal
Installation actuator after valve leakage mostly due to torque setting error (deviation >10%), valve stem coaxiality offset >0.5mm or not reset stroke limit, suggest re-calibrate
Installing ball valve when need guarantee pipeline coaxiality deviation ≤ 1mm, flange parallelism error ≤ 0.2°, avoid forced alignment produce stress; Sealing face installation before
Ball valve before installation should check specification and pressure grade, perform appearance and sealing face inspection and use 0.5MPa air pressure pre-test no leakage, clean
Ball valve field installation needs to ensure horizontal or vertical direction deviation is less than 1°, flange bolts according to diagonal divided into 3 times
For API 6D ball valves to undergo API 607 fire resistance testing, design drawings, material certificates (EN10204 3.1), pressure rating and dimensional data, test procedures,
Adopt metal + soft seal dual structure, after fire burn metal seal leakage ≤ 100 ml/min;Packing select graphite withstand temperature ≥ 700℃;Valve seat add spring
When purchasing industrial ball valves, focus on verifying that the hydrostatic test reaches 1.5 times the design pressure, the pneumatic sealing test shows zero leakage,
Industrial ball valves in severe service most often fail because seal wear exceeds 0.2 mm/year, pressure fluctuations go beyond ±20% of the design value, or