FEM structure on the basis of the actual construction conditions for compliance improvements

Floating Production Storage and Offloading Tanker (FPSO) is a tanker offshore structure shape , compared with ordinary oil tankers , FPSO will withstand more severe loading conditions , and thus its hull structure should have a special durability and fatigue fracture strength to ensure that the location of the job continue to work  Valve manifold  to the production requirements of more than 40 years until the end of oil exploration . According to the survey of damaged FPSO injury , openings and through the horizontal longitudinal frame at the connection node and other structures are prone to fatigue damage of the site, it is necessary in the finite element numerical calculation based on the structural form of realistic 2 way manifolds of the construction conditions . FPSO tanker loading and unloading more frequently than , so loading and unloading on the hull caused by the low- cycle fatigue damage can not be ignored . Due to structural nodes in the design or production of an  Instrument valve manifolds  , supervision and management and other aspects of vulnerability , or encountered a typhoon and other adverse sea conditions , the FPSO hull structure will crack. Crack initiation at the weld toe early stages of sanding through the crack repair methods , you can achieve the purpose of extending the fatigue life of the structure . Current international and domestic fatigue strength for FPSO research work focused on how to prevent cracks on the structure for cracks after studies conducted are less.

Thread connection load transfer law

Oil drill male thread root portion due to severe stress concentration in the complex alternating loads , easy to crack initiation , resulting in joint fatigue fracture due to the complex structure , difficult to find a variety of crack fracture strength of the analytic expression patterns generally only be solved numerically . thread contact in three-dimensional calculation is extremely complex, this paper proposes a simplified calculation model gives a reasonable load transfer  Instrument valve manifolds  rules . Using three-dimensional finite element displacement method , more systematic study of the root portion of the male thread with semi-elliptical surface crack in a variety of load stress intensity factor variation . Male thread root for predicting crack after carrying capacity and remaining life , establishing flaw detection cycle , the development of waste sub- standard ,  2 way manifolds  the necessary fracture analysis parameters . Second, the calculation method simplified model of thread contact connection state oil drill pipe joints loaded. Calculating three-dimensional contact with the thread is very complicated and expensive , is not conducive to engineering applications .  Valve manifold , this article assumes the role by the torque T , the thread contact between teeth without the circumferential direction relative slip ; subjected to internal pressure , tensile and bending loads , the contact between teeth without radial relative sliding .

The role of the use of a variety of valve working condition Isolated Conversion

Electric locomotive control air piping system is an  Valve manifold  part of the piping system for electric locomotive pneumatic appliances, such as the pantograph, the main circuit breaker and safety protection devices such as door interlock or key box, high-voltage electrical cabinet with compressed air. Is to ensure the normal operation of locomotive  Instrumentation ball valve  part. In order to prevent backflow of compressed air to ensure the pantograph, the main circuit breakers and high-voltage electrical cabinet two position switch, electrical contacts and other aerodynamic components of the normal work in the electric locomotive control piping system which is Instrument valve  check valve, the use of the role of non-return valve isolated Conversion various conditions. Check valve in the practical application process, the most common failure is channeling the wind, that the phenomenon of compressed air countercurrent direct impact locomotives l bow, closing and other operations.

Commercial CFD software research and internal flow check valves

From the study of fluid flow valve mechanism departure, using numerical simulation valve internal flow, numerical simulation results to guide the design of the valve has  2 way manifolds  an important research direction. Numerical simulation tools, one can save test resources, shorten new product development time; hand it can display is difficult to draw from the test flow characteristics in detail. In this paper, commercial CFD software research and internal flow check valve, mainly to do the following tasks: outlines the current situation and the check valve design  Valve manifold  fluid  Instrumentation ball valve  the check valve in the common software applications. Details of the basic theory and computational fluid dynamics method, the calculation method for solving algebraic equations and a variety of mesh generation techniques. Finally, multi-channel Ball Check Valve internal three-dimensional incompressible turbulent flow was simulated, and the results are experimental verification.