Threaded connection, first at the end of the pipe thread wrapped with suitable fillers by hand fitting screw on and suitable pipe specifications (or chain pipe wrench tighten the clamp). Operation, the force must be uniform, only into the "no" back, tighten the pipe (valve) after the pipe thread should be left 2 button thread, and the residual packing to remove clean.
(1) connection tool
The common thread connecting tool pipe. There are two kinds of tubes: plain type (open type) and chain type (Lian Qianzi). Lianqianzi for large size and narrow space of the connection, the large diameter pipe by welding, so Lianqianzi has been rarely used. The specification is expressed by the clamp jaw center to handle tail length, different specifications for different diameter pipe installation, can not be used indiscriminately, otherwise, not hard enough connection is not strict, too much force, will pipe damage, refer to table 2.8 selection when using.
(2) interface filler
In order to ensure the tightness of the interface, prevent corrosion and easy to repair and disassemble, when the interface is connected, the thread should be inserted between the filler. Selection of packing types, and the nature of the media and parameters (pressure, temperature, etc.) related.
The commonly used packing material for hot water pipes at ordinary temperature is hemp wire, lead oil and Teflon raw meal belt. When the medium temperature is higher than 120 DEG C, the filler can be asbestos rope lead oil or thick lead oil.