O tipo de extremidade do tubo escolhido determinará como ele se conecta a outros componentes e para quais aplicações e componentes o tubo é mais adequado.
Extremidades do tubo normalmente caem em uma das quatro categorias:
plain ends (pe)
threaded ends (te)
bevelled ends (bw)
grooved mechanical joints or grooved ends
a single pipe can also have multiple end types. this is often designated in the pipe description or label.
for example, a 3/4-inch smls schedule 80s a/sa312-tp316l toe pipe has threads on one end (toe) and is plain on the other.
in contrast, a 3/4-inch smls schedule 80s a/sa312-tp316l tbe pipe has threads on both ends (tbe).
plain end (pe) pipe uses and considerations
pe pipes feature ends typically cut at a 90-degree angle to the pipe run for a flat, even termination.
in most cases, plain end pipes are used in combination with slip-on flanges and socket weld fittings and flanges.
both styles require fillet welding on either one or both sides of the fitting or flange and at the base of the fitting or flange.
where applicable, the plain end will be placed typically ⅛” from where the pipe rests to allow for thermal expansion during welding.
this makes them ideal for small diameter piping systems.
threaded end (te) pipe uses and considerations
typically used for pipes with a nominal size of three-inch or smaller, te pipes allow for an excellent seal.
most pipes use the national pipe thread (npt) standard which describes the tapered threads used on the pipe with the most common taper measuring 3/4-inch per foot.
this taper allows the threads to pull tight and create a more effective seal.
however, connecting the threads on a te pipe properly is essential to avoid damaging pipes, fittings, or flanges.
improper assembly or disassembly may lead to galling or seizing.
bevelled end (bw) pipe uses and considerations
used with buttwelding, bw pipe fittings commonly feature a 37.5-degree bevel.
these bevels are often applied by fabricators by hand or through automated processes to ensure consistency.
this allows for a perfect match with bw pipe fittings and flanges and easier welding.
grooved end pipe uses and considerations
grooved mechanical joints or grooved end pipes use a formed or machined groove at the end of the pipe to seat a gasket.
a housing around the gasket is then tightened to secure the connection and ensure optimal seal and performance.
the design allows for easier disassembly with a reduced risk of damaging piping components.