Governing Thickness of Non-Standard Flanges for Impact Testing
Governing Thickness of Non-Standard Flanges for Impact Testing
(OP)
I observed a conflict in two clauses of ASME Sec. VIII Div. 1 UCS-66 as follows:
UCS-66 (a)(3): The governing thickness of nonwelded parts, such as bolted flanges, tubesheets and flat heads, is the flat component thickness divided by 4.
FIG. UCS-66.3 (c): tg2 = tc;
where, tc = thickness of shell welded to flange.
Flange thickness is not considered.
What thickness shall be considered while checking Impact Test requirement for a Non-Standard Flange?
- Flange Thickness/4; as per UCS-66 (a)(3) or
- Thickness of shell welded to flange; as per FIG. UCS-66.3 (c)
I feel in case of FIG. UCS-66.3 (c), they have forgotten to specify note that," The governing thickness of 'A'; means Bolted Flat Cover, is the greater of tg1 & tg2. (which appears in Fig. (d) & (c))
In that case this FIG. UCS-66.3 (c) will be applicable only for determination of govering thickness of 'Bolted Flat Cover' & shall not be used for Flange by any means.
Please provide your opinion.
Thanks.
UCS-66 (a)(3): The governing thickness of nonwelded parts, such as bolted flanges, tubesheets and flat heads, is the flat component thickness divided by 4.
FIG. UCS-66.3 (c): tg2 = tc;
where, tc = thickness of shell welded to flange.
Flange thickness is not considered.
What thickness shall be considered while checking Impact Test requirement for a Non-Standard Flange?
- Flange Thickness/4; as per UCS-66 (a)(3) or
- Thickness of shell welded to flange; as per FIG. UCS-66.3 (c)
I feel in case of FIG. UCS-66.3 (c), they have forgotten to specify note that," The governing thickness of 'A'; means Bolted Flat Cover, is the greater of tg1 & tg2. (which appears in Fig. (d) & (c))
In that case this FIG. UCS-66.3 (c) will be applicable only for determination of govering thickness of 'Bolted Flat Cover' & shall not be used for Flange by any means.
Please provide your opinion.
Thanks.
Ashay Kadam
Manager
Mechanical Department
Uhde India Private Limited
Mumbai, India.





RE: Governing Thickness of Non-Standard Flanges for Impact Testing
Butt welded? See UCS-66 (a)(1)(a).
Corner joint? see UCS-66(a)(1)(b).
Not welded to another piece? See UCS-66(a)(1)(c).
Regards,
Mike
RE: Governing Thickness of Non-Standard Flanges for Impact Testing