Feb. 07, 2017
Saying of pressure vessels, we may think of gas storage tank and recovery tower. Here I will share some tech about pressure vessels.
The requirements of welding seam on pressure vessel head
The distance between weld center lines for tailor welded head ends is at lest 3 times thickness of plate, and no less than 100mm. When the head is formed by splicing formed valve plate and the top circular plate, the welding direction is only allowed to be radial and circumferential level. Those head ends with formed before jointed board. The splice weld should be polished and flushed with the base metal before forming.
The detection of steel plate used in pressure vessels
The carbon steel and low alloy steel with the thickness not less than 12mm which satisfy one of below conditions need ultrasonic inspection during the shell fabrication :
1. The vessels with medium of toxic degree is extremely hazard and high hazard
2. The vessels worked in the corrosion environment of moist H2S
3. The vessels with design pressure not less than 10Mpa
4. Other requirements needs ultrasonic inspection mentioned in “Supervision Regulation on Safety Technology for Stationary Pressure Vessels”