How does the pneumatic ceramic butterfly valve control the degree of opening and closing? 4、 Conclusion
1) There is stress concentration in the assembly gap on the root structure of the welded joint, so it is necessary to conduct CTOD test to investigate the fracture toughness of the joint.
2) The test results show that the minimum CTOD value of the weld and heat affected zone is 0.196mm, which is greater than the requirements of 0.125mm in Appendix A of API 1104 and 0.15mm in DNV-OS-C401. The weld itself meets the requirements of Class 1 pressure vessel in JB4730-94 through NDT, so it can be recognized that the welded joint has sufficient fracture toughness value, which is sufficient as the basis for post weld heat treatment free.
Pneumatic ball valve is a combination of pneumatic actuator and ball valve. It can replace manual operation, not only save a lot of manpower and material resources, but also control multiple ball valves at the same time. The pneumatic ball valve is relatively simple in structure, convenient in maintenance and high in relative safety. It is made of superior materials and properly used. Its service life can reach 1 million times. Pneumatic ball valve is evolved from plug valve. It has the same 90 degree rotation action, but the difference is that the cock body is a sphere with a circular through hole or channel through its axis. The proportion of the sphere and the passage opening should be such that when the sphere rotates 90 degrees, the inlet and outlet should be all spherical, so as to cut off the flow.
