Read the equal area reinforcement of ASME and GB in a table

Equal area reinforcement is the most common calculation in pressure vessel design.

20210912234157 70450 - Read the equal area reinforcement of ASME and GB in a table

The equal area reinforcement of ASME is basically the same as that of GB, but the details are slightly different. The table of small part is as follows:

Comparison content ASME VIII I GB/T 150
Restrictions on use No specific provisions are made RM < 450MPa, te < = 1.5T, T < = 38, see 6.3.2.1 of 150.3 for details.
Reinforcement range The reinforcement height of nozzle is 2.5t or 2.5tn + te, and the reinforcement range is generally smaller than that of GB. For sqrt (d * TN), when d > 6.25T, the range of GB is always larger than that of ASME, and the reinforcement range of GB for thin-walled vessels is larger.
Reinforcement exemption conditions

UG36-3 (a) it can be opened 89 on the shell with the minimum thickness of 10 mm and below, and 60 on the shell with the minimum thickness of more than 10 mm.

The principle is deformation coordination.

  • The design pressure is less than 2.5MPa; Nozzle outer diameter ≤ 89; The wall thickness meets table 6-1; It shall not be opened on AB weld;
  • The principle is equal area.

Nozzle neck thickness According to UG-45, except for manhole, the thickness is generally greater than or equal to sch40. Even if the takeover meets the exemption conditions of ug36-3 (a), the takeover still has to be close to sch40, which is almost the same as table 6-1 of GB150. If not specified, the required thickness + corrosion allowance of nozzle is generally calculated according to internal and external pressure, which is generally thinner than that of ASME. It is suggested that the wall thickness of nozzle should be sch40 (s) + corrosion allowance.
Splicing of reinforcing ring Splicing is allowed, but in general, the reinforcement area of the reinforcing ring should be * 0.75, and there is a signal hole for each piece of reinforcing ring. UG-37(h). Not mentioned in GB 150, JB/T 4736 reinforcing ring (2002) more clearly stipulates that radial split reinforcement ring is allowed for installation convenience.
Weld strength check Need to consider, see ug-41, but the general calculation is passed. It does not need to be considered. It is ensured by welding joints.
Edge cutting of forged pipe

The minimum angle of inclination is 30 degrees

According to figure uw-9-2, if not 1:3 trimming, the straight edge length of forged pipe is 1.5 times of thickness.

GB 150 needs 1:3 trimming, and the length of trimming is long, so that the nozzle extension is particularly high. It is recommended to take 1.5 times of straight edge and 45 ° of slope according to ASME.
Non radial opening The coefficient f needs to be calculated. The non radial and radial are different. For cylinder and conical shell, the section passes through the opening center point and the cylinder axis. Therefore, non radial calculation is the same as radial calculation.
Large opening Appendix 1-7 (opening rate 0.7) (1-9, 1-10 removed in 2017 Edition). The opening ratio was 0.9.

Source: China Flange Manufacturer – Yaang Pipe Industry (www.steeljrv.com)

(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)

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