In recent years, our country also pays more and more attention to the safety of the production device, so, greatly improve the safety of the device, can completely avoid human error in operation and cause accidents. Design of valve locks are unique, so far the main valve lock is to control operations with fixed valve handwheel, valves and valve cover at the end of the bolt connection, the connection way is to create two nut with internal thread, connect the chain with peg, middle side screws into the valve cover bolts of form a complete set with it, on the other side has an external thread is articulated with the end of screw nut connection, with a chain around the valve handwheel, live or move the pin chain at both ends and the external thread connection, the handwheel connected to the valve cover is vertical, such connection is as long as the lock valve, unless to loosen the middle articulated or damage, it won't be able to open the valve. Repair or open, close the valve, as long as the middle of the screw joint can be. Valve lock is mainly used in some often closed and often open valve, there are some maintenance temporarily open, close the valve, other need to lock the valve can also be used. A lock can also lock two valves, so that the main protection is not to mistakenly operate the accident.