The Problems Should Be Pay Attention When Selecting The Pipe Fittings
The Problems should be Pay Attention When Selecting the Pipe Fittings
In the last article, we have talked much on the engineering application of pipe fittings, in this article, the problem should be pay attention when selecting the pipe fittings will be talked.
1)The domestic standard of pipe is incomplete, and the pipe standard without the supporting pipe fittings standard should include pipe fitting model parameters and fitting materials standards. But the material standard or regulation is not complete, or the lack of such as dean shipment is requirements, testing and set rules, quality certificate of quality and technical requirements. Pipe material standard compatibility is poor, it is not made from the pressure piping to formulate the standard system. The selection of pipe in engineering has the standards, but no corresponding standard of forgings and castings. The tube forgings standard adopts the standard of pressure vessel forgings, without considering the differences, such as welding, filming inspection rules.
2)The fitting standards is differ in thousands ways, lack of consistent and systemic content, this will cause inconvenience in use.
3)No testing standard of pipe fittings, only GB12459, GB13401 standard stipulates the pressure calculation of the steel seamless pipe and welding pipe fittings, and there is no other type testing to ensure the quality of pipe fittings manufacturing standards or to perform a standard.
Steel metal pipe fittings to meet different purposes, conditions and varied structure, the most widely used is elbow, tee and reducer. The commonly pipe connection includes butt welding, socket welding connections and pipe thread connection. Usually, DN50 or the above pipeline adopts butt welding pipe fittings, pipeline under DN50 adopts socket welding connections pipe fittings or pipe thread connection. The selection of sealing welding pipe fittings, first should be based on the design of the pipeline system the nature of the medium pressure, design temperature and tube, the second is to consider the comprehensive factors such as economy and life, and according to its place of piping design pressure, design temperature to determine the pipe using a temperature rating. Choose branch connection pipe leads from the head of branch pipe, if the diameter is the same, should try to use three-way connection; When the branch pipe diameter less than or equal to DN50, choose branch units, half pipe or pipe fittings such as strengthening branch connection pipe fittings; In addition, according to the actual circumstances of the project, it can also be used directly on the head of the structure of the welded pipe, but must check whether the branch pipe joint needs reinforcement.