What type of Flange do people mean to refer to when
they speak of a Companion Flange?
About Companion Flanges, the term refers to any flange that fits together in
Companion to another flange. In oilfield
language, persons may call blind, threaded, test, and weld neck flanges,
"Companion Flanges" the way adults may call children of every stripe,
"kids." At WOODCO USA we casually describe all loose flanges (meaning not
integral with an equipment body), with the sealing surface on
one side and a pipe thread entrance on the other, as Companion Flanges.
Only flanges with drilled through bolt circle holes fit this
category.
The flange shown below, a scale illustration of a
2-1/16" 5M flange, has a 2-3/8" EUE 8 Round thread as shown. This flange
also may commonly have a 2" Line-Pipe thread. Persons may call this
flange, with either thread, a Companion Flange. Calling this flange
shown, a 2-1/6" 5M flange, threaded 2-3/8" EUE 8 Round, will provide a
much more reliable description.
Today, some technical documents, e.g. API Spec 6A,
categorize the flanges sometimes called Companion Flanges as "loose
connectors" or "loose flanges", and the definition of this category
includes blind, threaded, test, and weld neck flanges, as well as those
with tap end studs, e.g. DSA's, etc.
For more
about Flanges, and a brief history, Click Here.
