News Center

Three kinds of failures: cast steel gate valves common crack, sealing surface crack, card, the following is the cause of cast steel gate valves the failure to do the following analysis:
A, cast steel gate valves crack, crack (or deformation) at the bottom of the main gate is appeared in the parallel-plate structure products, at the bottom of the ram directly impacts such as gate valves at the bottom of the valve body, much due to improper denso debugging of electric valve, close the trip without limits or limit failure easily happened.
B, cast steel gate valve plug: cast steel gate valve gate and show the ram card in the valve body lumen guide rail side, away from the valve stem, even by bad design and manufacture of the main causes, such as guide rail contact width is too short or too long, guide rail surface roughness, etc.
When ram card plugs in the valve seat and valve stem force lift, often appear gate t-slot fracture or deformation, and avoid the "booster" abnormal factors, two reasons and closing force and temperature difference are worth noting.
Typical temperature conditions such as the valve in the cold closed hot again after open, due to heat expansion elongation stem ram compaction, further increased the closing of the gate torque, lead to gate wedge.
Shut down as hot, cold open, caused by fork width on both sides of the seat thermal deformation, cold is contractive decrescent, resulting in gate wedge.
The above two states such as with the closing force is too large, namely too tight, such as improper denso driver debugging or improperly use power institutions such as wrench or lever, increases the chance of gate wedge;
C, cast steel gate valve sealing surface crack: mainly appeared in the steel materials of the valve sealing surface crack, often caused by the process is not reasonable.
Reasonable material selection and reasonable control of welding process parameters can be avoided.