Refer to ASME B36.19M Table 2-1
Note that dimensions are same only for NPS10 (SCH40S) or under.
For NPS greater than 10, dimensions do not conform to ASME B36.10M (not stainless) (NOTE (2))
Technical code related question; is it correct to state that, when
- using B36.10, the right designation is NPS8" STD or NPS8" Sch 40
- using B36.19, the right designation is NPS8" Sch 40S (but not NPS 8" 40S)
Huub
- You never get what you expect, you only get what you inspect.
XL83NL,
Most would write them as NPS8 sch40, with no inch marks.
And I don't believe that current editions of B36.19 list the names of sch (STD, XS and such) only 5s, 10S, 40S, and 80S.
B36.10 does list Std, XS, and XXS for some sizes.
And no wonder that people get confused ......
You're correct Ed, I should've dropped the inch marks (i.e. NPS 8 rather than NPS 8").
However, I think both B36.10 and B36.19 require you to put Sch. ahead of the number.
[ul]
[li]Referring to B36.19 (Im on the 2018 edt.), ch 4. In the 2nd sentence, it continuously mentions Sch. (or Schedule, if you like) ahead of the schedule-number or -designation.
[/li]
[li]B36.10 (again the 2018 edt.) does the same; in the ch 8 it talks about Schedule 80, Schedule 40, etc.
[/li]
[li]Both standards, in Table 2-1, have the same Column name for the schedule numbers: Schedule No.. This indicates that if 40 is used, regardless of what standard is applied, the correct designation requires one to put Schedule prior to the number.
[/li][/ul]
When using the designations Standard, Extra-Strong, and Double Extra-Strong (or STD, XS and XXS if you like), it's been my understanding that (acc. Ch 8 per B36.10) this shall not be prefaced by Schedule, since they're Identifications acc. Table 2-1, rather than Schedule numbers.
Huub
- You never get what you expect, you only get what you inspect.
That was partially addressed/answered before. My question was about the right format to designate a certain wall thickness. As I recall, Schedule Standard isnt the right terminology. 40S doesn't seem to be the right one either (although everyone seems to understand what you mean, just like when someone says a B16.5 300# flange).
Huub
- You never get what you expect, you only get what you inspect.
The sch designations link directly to the tables in 36.10/19 that list the measured wall thickness and minimums.
And how would you write that? 3NPS x 0.216" aw, or 3.5" x 0.216"aw ?
Thanks,but NPS3sch40 is actually very clear.
We used to see orders for non-sch wall, usually as minimum wall. These always overlapped a std sch thickness but often with skewed or special tolerances. Such as 2NPS with 0.160" min wall (spec is 0.154" nominal).
