Equipment takeover
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I am currently working on equipment design, and I’m wondering what requirements apply to the connections used on such equipment. If it’s a pressure vessel, for example, with a design pressure of 1.5 MPa, are there any specific requirements regarding the thickness of these connections? For pipes with a DN50 diameter, there are various wall thickness options – which one should be chosen? Are there any standards that can guide this decision? Additionally, the length to which the connections should extend isn’t yet determined. I’d appreciate some advice from everyone.
It might be in the mechanical design manual. The stress on the equipment due to external pipes also needs to be considered.
It is sufficient to match the pressure rating of the pipe with the pressure requirement of the equipment; for a DN50 pipe at 1.5 Mpa, the commonly used sizes of φ57×3.5 or φ57×4 will suffice.
The main consideration is ensuring that the pressures are matched, and welding performance also needs to be taken into account; walls that are too thin cannot be used as their welding quality cannot be guaranteed.
Reply to 3# chinazwr: Thank you all for your helpful guidance, but I feel that the suggestions given are rather general. Does anyone have any materials related to takeover procedures? Standards or anything else related would be appreciated. Thanks!
If it is a pressure vessel, calculations are to be carried out in accordance with the GB150 standard, including the wall thickness of the vessel and the wall thickness of the equipment connections. The takeover length is primarily determined by the welding space and the space required for bolting, with additional consideration given to the length needed for opening holes for reinforcement. For DN50 fittings, in GB150, if the conditions for not requiring hole reinforcement are met, reinforcement calculations need not be carried out. The φ57×4 fitting should be sufficient to meet the reinforcement requirements, so no calculation is needed.
Reply to 6# HZCR: Thank you. GB150 doesn’t cover many details regarding connections; I’m still not quite sure about them
The wall thickness of the pipe can be calculated by determining the allowable stress at the design pressure and design temperature, and then referring to a table
The information on floor 6 is quite comprehensive. The openings in the equipment are calculated in accordance with relevant standards such as GB150 or ASME. As for the length to which the pipe ends extend outside, \"consideration is given to the space needed for welding and bolting, as well as the length required for reinforcing the openings.\" Additionally, if insulation is necessary for the equipment, the thickness of the insulation layer to be applied must also be taken into account. If there is an opening at the top of the equipment, the platform issue may also need to be considered; in such cases, the piping specialist can provide you with the required length for the extension. For some equipment, the length to which the pipe outlet extends can be determined by the equipment specialists after taking into account normal circumstances; for others, it needs to be decided by the piping specialists. Under normal circumstances, the equipment outlet should extend 150 mm outward. As for wall thickness, the calculation formulas used in the equipment field are applied (it may be the formulas for calculating the wall thickness of cylinders; this needs to be verified, as they differ from those used by the piping field for calculating pipe wall thicknesses. At least the values assigned to allowable stresses are different, with the allowable stress values in the equipment field being more conservative and safer).
Reply 6# HZCR: The formula for calculating the wall thickness of the nozzle is the same as that for the cylinder. The resulting value is quite small; therefore I don’t understand why some people would use a DN57×10 nozzle – isn’t its wall thickness too thick?
Reply to 9# Sunshine2010: It’s very detailed, thank you, I’ve learned something