Calculation
Pressure vessel safety valve pressure calculation
1 、 Pressure vesse
nominal diameter/mm
its internal diameter as the nominal diameter
300，（350），400，（450），500，（550），600，（650），700，800，900，1000，（1100），1200，（1300），1400，（1500），1600，（1700），1800，（1900），2000，（2100），2200，（2300），2400，2600，2800，3000，3200，3400，3600，3800，4000，
when using seamless steel pipa as a cylinder, its external diameter as the nominal diameter /mm
159，219，273，325，377，426
2 、working pressure and design pressure
The maximum working pressure occurs when pressure vessels is under normal operating conditions is called the maximum working pressure of the container, showed with PW. Design pressure of the container should be higher than its maximum working pressure.
P=1.05~1.1Pw
1 Containers fitted with safety valve
maximum working pressure PW/Mpa
‹1.0
1.0-1.5
opening pressure PK/Mpa
PW+（0.035~0.05）
PW+（0.11~0.18）
maximum working pressure
≥1.6
≥4.0
opening pressure PK/Mpa
PW+（0.11~0.115）
PW+（0.105~0.11）
2 Containers fitted with the bursting disc, the design pressure should be not less than the design burst pressure limit of bursting disc. It can adopt
（1.15~1.75）PW
3、design temperature
Design temperature means the container in the normal operating conditions, in the corresponding design pressure, the set pressure metal components temperature.
4、Calculate pressure
Calculate pressure is defined as under the corresponding design temperature, used to confirm the pressure components thickness pressure, including the liquid column hydrostatic pressure
5、allowable stress
the steel plate used in manufacture container, its size under the design temperature of the allowable stress values, directly determines the container strength, is one of the main design parameters
6、Coefficient of welded joints
Cylinder is made by the volume-based post-weld, between the cylinder and sealing head is through the welded together, at the strength of welded joints is higher than, equal to, or less than the strength of steel itself, also is one of important factors that influences the whole container intensity level.
