What is a pressure vessel? We can think that where the pressure of liquid media sealed equipment is called pressure vessels. Pressure vessel generally refers to the petrochemical and other industrial production used to complete the reaction, heat transfer, mass transfer, separation and storage and other production processes, and has a specific function of bearing a certain pressure of the equipment. It is mainly used in the petrochemical industry, energy industry, scientific research and military industry; at the same time in the civil industry has also been widely used, such as gas or liquefied petroleum gas tanks, various accumulators, heat exchangers, separators and large pipeline projects.
1、Definition of pressure vessel
According to the "Pressure Vessel Safety Technical Supervision Regulations", pressure vessels must have both: the highest working pressure ≥ 0.1MPa, the volume of the container ≥ 25L, the working medium for gas, liquefied gas and the highest working temperature above the standard boiling point (refers to an atmospheric pressure boiling point) of the liquid these three provisions. Otherwise, it belongs to the atmospheric pressure vessel.
Pressure vessel is mainly cylindrical, a few for the sphere or other shapes. Cylindrical pressure vessel is usually composed of cylinder, head, receiver, flange and other parts and components, the higher the working pressure of the pressure vessel, the thicker the cylinder wall should be.
2, the classification of pressure vessels
There are many ways to classify pressure vessels, according to different methods can have different classifications.
2.1 Manufacturing classification: can be divided into five kinds of welded containers, forged containers, riveted containers, cast containers and combination containers.
2.2 Classification by material: steel containers, non-ferrous metal containers and non-metallic containers.
2.3 Classification by wall thickness: can be divided into thin-walled containers and thick-walled containers of two kinds.
2.4 Classification by shape: there are spherical containers, cylindrical containers, conical containers.
2.5 According to the classification of pressure: there are internal pressure containers and external pressure containers.
2.6 According to the design pressure division
Low-pressure vessel (code L) 0.1MPa≤p﹤1.6MPa
Medium pressure vessel (code M) 1.6MPa≤p﹤10MPa
High pressure vessel (code H) 10MPa≤p﹤100MPa
Ultra-high pressure vessel (code U) p≥100MPa
2.7 According to comprehensive factors (such as the height of the pressure vessel, the size of the volume, the degree of hazard of the medium and the important role in the production process)
Class I vessels: refers to low-pressure vessels with non-flammable or non-toxic media, or low- pressure separation vessels and heat transfer vessels with flammable or toxic media
Class Ⅱ container: refers to one of the following cases of containers
1. medium-pressure containers
2. Low-pressure containers with highly toxic media
3 with flammable or toxic media of low-pressure reaction vessels and storage tanks
4. Low-pressure waste heat boilers with an internal diameter of less than 1m
Class III containers: refers to one of the following cases of containers
1. high-pressure, ultra-high-pressure containers
2 medium pressure reaction vessels with flammable or toxic media, medium pressure storage tanks or tankers
3 large low-pressure containers and medium-pressure containers with highly toxic media
4 medium-pressure waste heat boilers or low-pressure waste heat boilers with an internal diameter greater than 1m
2.8 According to the container working temperature division
High-temperature containers 200 ~ 500 ℃
Room temperature container natural ambient temperature
Low temperature container -20 ~ -253 ℃
2.9 According to the division of pressure vessel role
Reaction pressure vessel is mainly used to complete the physical and chemical reaction of the medium. Such as reactor, generator, decomposition pot, cooking furnace, etc.
Heat exchange pressure vessels are mainly used to complete the medium heat exchange vessels. Such as waste heat boilers, heat exchangers, coolers, evaporators, etc.
Separation pressure vessel is mainly used to complete the fluid pressure balance of the medium and gas purification and separation of vessels, such as separators, filters, oil collectors.
Storage pressure vessels are mainly used to contain raw materials for production and life gas, liquid, liquefied gas containers. Such as the individual forms of storage tanks, tankers, etc.
2.10 According to the installation mode classification.
Fixed pressure vessels: fixed installation and use of location, process conditions and operators are also more fixed pressure vessels.
Mobile pressure vessels: the use of not only the internal or external pressure load, handling process will also be subject to the impact caused by internal media shaking, as well as the external impact and vibration load brought about by the transport process, and therefore in the structure, use and safety have their special requirements.
