High temperature steam pipe is an important part of the power plant. In order to coordinate the pipeline thermal expansion and reduce the pipeline thermal expansion stress caused by the higher altitude difference and larger horizontal span

a lot of constant supports and hangers are designed in pipeline. But because friction moment exists on the rotating shafts

constant supports and hangers are not a constant force

the load deviation will make the pipeline deviate from the designed cold and hot line

and the pipeline stress will increase. For controlling the quality of constant supports and hangers

there are two quality performance control indexes among the relevant domestic standards

namely the constant degree and the load deviation degree. This article focuses on the load deviation degree. It finds out that

the load of putting out pin measured by different loading directions is different

resulting in a large difference in load deviation degree due to friction moment of the rotating shaft of the constant supports and hangers. So the load of putting out pin shall not be used as a representative parameter. The study proposes that the average load shall represent the position of the displacement-load curve

which is a representative parameter of constant supports and hangers. A new formula for calculating the average load deviation degree is proposed. It is suggested to modify the related standards to improve the quality of the constant supports and hangers.