How to properly select and use metal expansion joints

As a frequently used pipeline accessory, the correct selection and use of metal expansion joints is very important. The following aspects should be considered when designing.
1)Selecting the right metal expansion joint
According to the medium in the pipeline, pressure, pipeline expansion and the angle to be adjusted during installation, choose the expansion joint of the corresponding material, pressure level and connection method.
2）Comprehensive consideration of various factors to determine a reasonable installation location In general, metal expansion joints are used together with valves and check valves. Some of the sample wood in the installation and use of precautions only states: expansion joint installation in the valve and check valve after. Some people believe that this provision alone is not enough. In addition to the design to meet the normal operating requirements, should also be considered to meet the maintenance requirements. Especially in the maintenance of equipment, valves, valves after the pressure in the pipeline still exists, at this time: design according to the media flow will be installed in the valve after the expansion joint, should be considered after the expansion joint on the pipeline set up a valve for maintenance; for the pipe in the section intersection of large and infrequent maintenance, from an economic point of view, the expansion joint can be modified, set limit devices, as shown in the figure; such as the pipeline has been set up when there are two valves, expansion joint can be installed between the two valves. In the case shown in the figure should be installed in the expansion joint between the electric butterfly valve and manual butterfly valve, the manual butterfly valve can be closed during maintenance, the equipment in front of it and the valve can be serviced or replaced. The limiting function of the metal expansion joint is to lock with double nuts at the large expansion volume. The pipe is free to expand and contract in the allowed expansion volume, and once it exceeds its large expansion volume it acts as a limit to ensure the operation of the pipe. The role of this device and the influence it plays in the whole pipeline line is not negligible. The metal expansion joint is a steel expansion joint product manufactured using the standard, which can adapt to the connection of valve and pipeline and pipeline compensation, and facilitate the disassembly of the valve.