The concept of stress



A concept of pressure in a pressure container is the force that vertically appeals to the unit area of an object. The exact title should be called stress intensity, except that it is used to being called stress. The unit of pressure is usually atmospheric pressure, and the performance is revealed in kilogram force/cm2 in the project unit system. When the pressure is low, the performance is also revealed in water column or mercury column. The pressure units adopted in the world are different, such as "bar", "Pa", Newton (n) or pound.



The pressure in a pressurized container is measured by a pressure gauge. The pressure indicated on the pressure gauge is called gauge pressure, which reveals the pressure value of the external medium of the container exceeding the atmospheric pressure. The pressure in the container should be the pressure indicated by the pressure gauge plus the atmospheric pressure nearby.

Vessels and pressure vessels



container



Container is a space component composed of curved surface for holding materials, and it is the general name of all kinds of equipment outer shells used in chemical industry, oil refining, medicine, food and other production. Generally, the container is formed by cylinder, head (end cover), flange, support, receiving, manhole, hand hole and sight glass.



pressure vessel



Pressure vessel generally refers to the closed vessel which is used in industrial production to realize the basic production experience such as feedback, mass transfer, heat transfer, aggregation and storage, and can bear pressure. That is, closed containers containing pressure media are collectively referred to as pressure vessels.

Demand for safety of pressure vessels



As the pressure vessel is a pressure-bearing equipment, it is operated under various media and conditions, so its destructiveness is often very old once it is pregnant with AIDS accidents. In order to produce safely, many industrial countries regard boilers and pressure vessels as a kind of special equipment, set up special institutions to develop safety supervision, and apply for standardized development plans, production, application and operation in strict accordance with defined rules and regulations. Basic laws and regulations concerning pressure vessels in China include:



(1) Regulations on Safety Supervision of Special Equipment

(2) Regulation for Safety Skills Supervision of Pressure Vessels

(3) Provisions on Acceptance and Operation of Qualification of Planning Units of Pressure Vessels and Pressure Pipelines

(4) Operation Mode of Boiler and Pressure Vessel Production Supervision

(5)GB150 Steel Pressure Vessels

(6)GB151 Shell and Tube Heat Exchanger

(7)JB4732 "Steel Pressure Vessels-Specification for Analysis Plan"