Have noticed some writers refer to a pipe as a "group 3 pipe" or a "group 4 pipe" or what have.
From context, this means to have to do with size.
Can someone advise and point me to a reference or standard?
Thanks. (Always seems to be an answer lurking hereabouts.)
From context, this means to have to do with size.
Can someone advise and point me to a reference or standard?
Thanks. (Always seems to be an answer lurking hereabouts.)