1. The valve connected with the pipe thread is connected with the pipe thread of the pipe end, wherein the inner thread can be a cylindrical pipe thread or a tapered pipe thread, and the outer thread must be a tapered pipe thread.

2. The inner threaded connection gate valve and the tube connected connection, needs to control the tube end external thread length size. In order to avoid excessive rotation of the pipe end to the top pressure valve pipe thread inside end, resulting in seat deformation and affect the sealing.

3. Pipe thread connection valve, installation tightening should wrench the thread of the same end of the hexagonal or octagonal parts, should not wrench the other end of the valve hexagonal or octagonal parts, lest cause valve deformation.

4. Flange connecting the valve flange and the end of the flanges is not only consistent with the size of the specification, but also the nominal pressure is consistent.

5. Cut-off valve, gate valve in the installation and commissioning process found in the valve stem leakage, tighten the packing place to tighten the nut can be, and pay attention to the force can not be too large, to no leakage limit.