Shandong heat exchanger gasket, 16MnR, is a hot rolling or normalizing process of steel commonly used in boiler pressure vessels. The Mn content of low alloy steel is low. The tensile strength of the material is about 20g 412-540. The elongation is 19-21% and the elongation is higher than 24% of 20g. There is a technical condition for ordering 16MnR on gb6654 and a 16mnre state, which means that the 16Mn state properties and uses of the added rare earth elements are similar to those of 16Mn, but the impact toughness and cold bending properties are higher than that of 16Mn. All of them are low alloy steel. 2 ″ U-type tube and shell heat exchanger, a kind of petrochemical equipment, which is composed of main components such as tube box, shell and tube bundle, is named after its heat exchange pipe is U-shaped. The U-tube heat exchanger has only one tube plate. Both ends of the tube are fixed on the same tube plate, as shown in Figure 1. The characteristics of this kind of heat exchanger are that the seal bundle of Shandong heat exchanger can be freely retracted, and the thermal stress state thermal compensation performance is good due to the temperature difference between the shell and tube. The tube process is double pipe process is long, the flow rate is higher, the heat transfer performance is better. The tube bundle can be extracted from the shell body for easy maintenance and cleaning, and the structure is simple and cheap. However, it is difficult to replace the pipe in the middle part of the tube bundle. Because the bending radius of the inner tube cannot be too small, the pipe distribution in the center of the tube plate is not tight, so the number of tubes cannot be too many and the gap in the center of the tube bundle makes the shell flow easy to short circuit, which affects the heat exchange in the shell. In addition, in order to make up for the wall of the pipe after the bend, the thick pipe is needed for the straight pipe. This affects the application situation of the pipe shell, which is only suitable for the case where the temperature difference between the shell and the shell wall is large or the medium in the shell side is easy to scale, and the pipeline medium is clean and it is not easy to scale. The high temperature, high pressure and strong corrosiveness are not easy to scale. The type and basic parameters of such heat exchanger have been series JB / t4717-92, and the design and manufacture of the third edition of floating head heat exchanger and condenser U-tube heat exchanger series - type and parameters of Sinopec shall comply with GB151-1999 tube and shell heat exchanger and other standards. 3. Business card floating head heat exchanger new floating head heat exchanger floating head end structure. It includes cylinder, outer head cover side flange, floating head tube plate, hook ring, floating head cover, outer head cover and screw hole The composition of steel ring is characterized by the concave or ladder sealing surface on the inner side of flange on the outer head cover side, and drilling holes near the outer side of the sealing surface, threading or welding multiple screws evenly distributed. The hook ring and related parts are canceled. The sealing groove of floating tube plate is the original concave groove and a ladder groove with the center of the tube plate as the center is slightly larger than the outer diameter of the tube bundle The split groove of tube plate is connected with ladder groove only, but not concave groove. 4. Fix the tube plate heat exchanger to fix the tube plate and shell of the seal pad tube plate heat exchanger of Shandong heat exchanger. When the temperature difference between the two fluids is large, weld a compensating ring or expansion joint on the proper position of the shell. When the shell and tube bundle thermal expansion are different, the compensation ring will be slowly elastic deformation to compensate for the thermal expansion caused by the temperature difference stress. The characteristics of the material are simple structure, low cost, difficult cleaning and maintenance of shell process * * is a clean and non fouling material. Fixed tube plate heat exchanger mainly consists of shell, tube plate, tube bundle, head gland and other components. The structure of fixed tube plate heat exchanger is that the tube is fixed on the tube plate by welding or expanding the two ends of the tube bundle in the shell. The tube plates at both ends are directly welded with the shell. The inlet and outlet pipes of the shell process are directly welded to the shell. The outer circumference of the seal backing plate of the heat exchanger and the flange of the end are bolted. The inlet and outlet pipes of the pipe side are directly welded with the head of the pipe Several baffles are set up in the starting tube bundle according to the length of the heat exchanger. The tube side of this heat exchanger can be divided into any number of passes by partition. Fixed tube plate heat exchanger has simple structure, low manufacturing cost, convenient cleaning of pipe process, and pipe process can be divided into multi-stage shell process or double pass condition with wide specification range. Therefore, it is widely used in engineering. The difficult cleaning of shell side is not suitable for dirty or corrosive medium. When the difference of the expansion of the seal gasket of Shandong heat exchanger is large, the expansion joint can be set on the shell to reduce the thermal stress caused by the temperature difference between the pipe and the shell.