ASME Section 1 PG 52.3 Interpretation

[KRosell]

Hi all,

I'm needing some help interpreting the meaning of ASME Section 1 PG 52.3 Ligament efficiencies Longitudinal vs Circumferential stresses.

In 52.3 "strength of those ligaments between tube holes that are subjected to a longitudinal stress shall be at least one half the required strength of those ligaments that come between the tube holes that are subjected to a circumferential stress"

I see this as saying the longitudinal (horizontal) ligament efficiency shall be at least 1/2 the circumferential efficiency. L > or = 1/2 C

Thank you for your help!

 

[viper3982]

Standard Designation: BPV Section I
Edition/Addenda:
Para./Fig./Table No:
Subject Description: PG-52.3, Circumferential Ligaments
Date Issued: 06/29/1998
Record Number: BC98-160
Interpretation Number : I-98-15
Question(s) and Reply(ies):
Question: Does PG-52.3 require the cross-sectional area of individual ligaments, between openings transverse to the vessel axis, to be half the cross-sectional area of individual ligaments between openings that are parallel to the vessel axis?

Reply: No. PG-52.3 requires the minimum ligament efficiency for openings transverse to the vessel axis, calculated using the circumferential pitch and the formula of PG-52.2.1, to be not less than half the minimum ligament efficiency for openings parallel to the vessel axis, calculated using the same formula.

 

[A clark]

Good Morning,
PG-52.3 was revised several years ago, it is now permitted to have the circumferential aligned holes govern the design. PG-52.3 has a formula to calculate the equivalent longitudinal efficiency of circumferential ligaments. I suggest that you review the current Section I.