Why does fire fighting pipe crack when grooving?

Grooved pipe connection is often used in the construction and installation of fire fighting pipes. Therefore, it is often necessary to groove fire fighting pipe. If the pipe cracks during grooving, it will be very annoying. Why does fire fighting pipe crack when grooving? The reasons mainly involve pipe material factors and human factors.


I. Material factors


Pipe material is the primary factor. If  pipe cracks during grooving, firstly check pipes’ quality issue. Common quality issues that cause pipe cracking mainly include: 


(1) The problems of welded pipe itself: the shrinkage stress of welded pipe is too high, uneven heated or unreasonable welding method and sequence will lead to weld cracking 


(2) Insufficient pipe thickness: pipes' wall thickness is required when grooving, in general ,only the thickness meets the national standard, pipes can be grooved according to construction requirements. However, in order to save costs, some contractors use thin pipes instead of thick ones, which will cause some problems during grooving.


(3)Pipe is not straight: Pipes may collide during handling and long-distance transportation, resulting in pipe bending. When grooving bending pipe , cracks may occur on one side due to non-homogenous force stresses.


(4) Poor quality of pipes: Good raw materials are needed to produce high-quality galvanized pipes. However, in order to save costs, some manufacturers use wasted materials to make pipes, which will lead to relatively poor quality of pipes, low carbon content and easy to crack when making grooves.