ASME B1.20.1 dimension h 1

[kwallo]

Could anyone who has access to ASME B1.20.1 please advise the value of dimension h "height of thread" for 1" and 1/2" NPS pipe.

Thanks

 

[rneill]

Dimension h for 1" is 0.06957" and for 1/2" is 0.05714 per Table 2 of the standard.

 

[AlejandroFernandez]

h [in]
threads/in Maximun- Minumin
11.5 0.06957-0.06261
8 0.10000-0.09275
Table 1 of ASME B1.20.1

Alejandro Fernández
I+D&I
Sitelca

 

[rneill]

Table 2 provides the basic dimensions of taper pipe threads and indicates the following:

1/2" pipe has 14 threads/inch and h = 0.05714"
1" pipe has 11.5 threads/inch and h = 0.06957"

These are the values of h that would be used in pressure design calculations.

Table 1 provides more detail and in particular tolerance information as it lists maximum and minimum values of h. Table 1 shows the following:

14 threads/inch, h-max = 0.05714" & h-min = 0.05071"
11.5 threads/inch, h-max = 0.06957" & h-min = 0.06261"

Note: when doing a pressure design calculation we would want to use the maximum value for h as this results in the thinnest remaining wall thickness. On that basis, the value of h we would use is the same value published in Table 2.

Pipe 2 1/2" and larger has 8 threads/inch and thus an h of 1.0000"