There were two very different answer answer, which is correct? Hope professional advice. thank you
In the hydraulic and pneumatic equipment, only air tank and the accumulator belongs to pressure vessel, need qualifications, the rest of the electromagnetic valve, cylinder, cylinder does not belong to the pressure vessel
Stress refers to holding gas or liquid, carrying a certain pressure airtight device View from literal meaning, oil cylinder, cylinder, as well as hydraulic components, are not airtight device, such as A, P.. So do not belong to the pressure vessel. See: http://baike.baidu /view/41619.htm
Also belong to the pressure vessel, oil cylinder pressure is big, cylinder cylinder pressure. Need qualifications.
Do not belong to the pressure vessel Only the container at the same time satisfy the following three conditions, pressure vessel is called: (1) working pressure (note 1) greater than or equal to 0.1 Mpa (work pressure refers to the pressure vessels under normal working condition, the top can reach the highest pressure (pressure)); (excluding hydrostatic pressure) (2) the internal diameter (for non circular cross section width height or diagonal line such as rectangle for the diagonal ellipse for long axis) is not less than 150 mm in the container (3) working medium for gas, liquefied gas or liquid temperature is higher than the standard boiling point; See: http://baike.baidu /view/41619.htm
