Evaluation of residual stresses in lock valve elements of petrochemical productions

Abstract

Abstract. Lock valves of the pipeline is an important and responsible product. It is designed to shut off the flow of liquid or gaseous fluid. During transportation ambient temperature reaches 400ᵒC, and the pressureover 30 MPa. Leakage of the fluid through the details and components of lock valves is not permitted. The batch of high-pressure valves was withdrawn after some time of its usage at the petrochemical enterprise. Premature wear of input branch pipe saddles was dis-covered. The cause of destruction of the input branch pipe saddles was erosion be-cause of abrasive particles, which are present in the working fluid. Locking node of the high-pressure armature is highly loaded element. The welding depositions are widely used to increase the strength of the valve locking node. It is established that under recommended heat treatment of the valve an ordered microstructure is formed and residual stress in the welding deposition zone is reduced. The article shows the relationship of residual stress with microstructure of the material. The magnitude of residual stresses in high-pressure valve locking node -in the brunch pipe saddle and the adjacent zoneswas determined by x-ray method.

Investigation of Hadfield Steel Machinability in Milling Operations

“…Additional research is required to determine the effect of tool wear and temperature in the cutting zone on the output machining parameters and residual stresses [14][15]. The range of variable cutting data should be expanded by including the radial depth of cut.…”

The inverse task solution for the calculation of sweeps of sheet parts by integral geometry

“…The material of the investigated parts is the aluminum alloy of the Al-Mg-Mn group. The forming process is carried out by hydro-elastoforming [5][6][7][8][9][10][11] on a QFC type press by Quintus Technologies with a maximum pressure of 100 MPa.…”

Investigation of Welded Joints Made of Construction Steel by the Barkhausen Noise Method

“…The problem of residual stresses has been studied by many authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Residual stresses were evaluated by different methods, which are mainly destructive.…”

“…The Barkhausen noise method is used for estimation of the surface residual stresses in aircraft bearings [20], for detection of grinding burns [21][22][23], for measuring the depth of the carburized case and other parameters of the structure that can affect the ferromagnetic properties of steel [24][25]. The application of this method in weld seams is described in [4][5][6][7][8][9][10]26,27].…”