What is a pressure vessel condition diagram?

1. Content of the design condition diagram (table) The design condition diagram (table) is one of the bases used by designers for the design of pressure vessels, and it should include at least the following elements: operating parameters (including working pressure, operating temperature range, liquid level height, nozzle loads, etc.)； Location of use of the pressure vessel and its natural conditions (including ambient temperature, seismic design intensity, wind and snow loads, etc.) ； Medium components and properties ； Expected service life ； Geometric parameters and nozzle orientation ； Other necessary conditions required for the design, etc.; this design condition diagram (table) shall be deemed valid only after being confirmed and signed by the technical representative of the design client.

What was said on the 2nd floor is quite comprehensive; I’ll add some local expressions to supplement it. Generally speaking, the most common approach is for the property owner to entrust a design institute to carry out the process calculations for pressure vessels (to determine whether they should be vertical or horizontal)； Container size DN ； Parameters such as the size of each pipe outlet, etc., are calculated by the design institute, which then prepares a schematic diagram along with a table of technical specifications. These specifications generally include the details mentioned on the second floor. This diagram is sent by the owner to the manufacturing factory, where the factory refines the drawings and conducts strength calculations to determine the appropriate material dimensions and other details, thus creating a complete set of drawings ready for production. These drawings are submitted to the owner and also sent back to the design institute for verification to ensure that the refined drawings meet the requirements. Once approval is given, the manufacturing factory proceeds with production according to these drawings.

Is the pressure vessel condition diagram prepared by the owner and provided to the design institute?

Does that mean it was provided by the design institute? This diagram can be considered a simplified version of a pressure vessel. Is a qualification for pressure vessel design required to create such a diagram? The owner does not have the qualifications for pressure vessel design; can they draw this diagram themselves and provide it to the manufacturing factory?

Does that mean it was provided by the design institute? This diagram can be considered a simplified version of a pressure vessel. Is a qualification for pressure vessel design required to create such a diagram? The owner does not have the qualifications for pressure vessel design; can they draw this diagram themselves and provide it to the manufacturing factory?

It depends on the approach taken. In some cases, owners are simply looking for a cheaper option; they have their own technical staff who can prepare a simple diagram to outline the requirements, and then they hire an individual to calculate the details related to the process and strength requirements. That individual then completes the entire set of drawings, after which the owner finds someone to apply the design stamps (companies with design qualifications can do this for a small fee, handling the signing and stamping). Finally, the work is handed over to a small workshop to be carried out. Such situations do indeed occur. In that case, it’s sufficient for the owner to provide a simple diagram to explain the requirements. Alternatively, option 2 involves following the formal process: the owner commissions a design institute to carry out process calculations, and the institute prepares schematic diagrams (condition charts/tables) – the institute certainly has the necessary design qualifications. These diagrams are submitted to the owner for approval to ensure they meet the requirements, after which the owner passes them on to the manufacturing factory. Generally, for more proper and larger-scale projects, the approach of using level 2 is adopted. I have also handled projects of level 1 before; of course, those of level 1 are very simple – they involve empty storage tanks or basic heat exchangers with no complex internal structure.

No special qualifications are required to create pressure vessel condition diagrams; users, general contractors, design firms, and manufacturing units can all prepare them, but the person responsible for preparing them must have a certain level of technical expertise. It mainly includes basic design information and user requirements, all of which need to be provided by the user. (If the user does not provide seismic and wind load parameters, they can look up the codes for seismic design of buildings and codes for loads on building structures on their own, but this requires confirmation from the user.)

Design conditions – I’ve heard of a design conditions chart for the first time.

A design becomes effective once it is stamped with the special seal for design approval. The party commissioning the design of a pressure vessel must submit the design requirements for such vessel to the design firm in written form. The design conditions shall include at least the following: (1) Operating parameters (including operating pressure, operating temperature range, liquid level height, pipe connection loads, etc.) ； (2) Location of use of the pressure vessel and its natural conditions (including ambient temperature, seismic design intensity, wind and snow loads, etc.) ； (3) Medium components and properties ； (4) Expected useful life ； (5) Geometric parameters and nozzle orientation ； (6) Other necessary conditions required for the design.