Threaded Pipe Coupling, Female PT Both Ends
A full coupling with female PT taper threads on both ends, for joining or extending threaded pipe in a straight run. Shell mold cast in 202, 304 or 316 stainless steel, 1/8″ to 4″, Class 150.
One piece, threaded both ends.
A threaded full coupling is a short sleeve with a female thread at each end. It joins two male-threaded pipe ends in a straight line, or extends a run by one more length of pipe, and then it stays put: a coupling is one piece with nothing to loosen, so it is the joint for runs you do not plan to open. Full means both ends are threaded at the same size. A half coupling is threaded on one end only and welded to a pipe or vessel wall on the other, and a reducing coupling changes size from one end to the other; this page is the full coupling.
Ours is shell mold cast in our own plant in Taiwan in 202, 304 or 316 stainless steel and machined after casting. Sizes run 1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1-1/4″, 1-1/2″, 2″, 2-1/2″, 3″ and 4″, with the same size on both ends; the 3/4″ size also comes in two body lengths, 20L for tight spots and 30L for more thread engagement. The threads are PT taper threads. PT is the Japanese designation for the 55° taper thread that BSPT, R and Rc also describe; it seals on the thread with tape or sealant. It is not the same as NPT, which is a 60° thread and should not be mated with it even where the nominal sizes look alike. If your line needs an NPT coupling, tell us with the inquiry; NPT is made to order.
The pressure class is 150. On stainless threaded fittings that number is a class designation, not a limit of 150 psi; the working pressure depends on temperature and is set by the fitting standard the class belongs to. For water, air and general fluid lines at ordinary temperatures it carries more than the pipe around it.
Choose 304 for water, air and general service, 316 where chlorides are present, and keep the run in one grade. If you expect to open the joint later, use a pipe union there instead of a coupling. It matches our stainless steel hex pipe nipple, threaded 45 degree elbow, street elbow, pipe cap and pipe cross, so one take-off list covers the whole threaded line.
- Model
- FT-TCOUP
- Body
- 202, 304 or 316 stainless steel
- Size range
- 1/8″ to 4″
- Thread
- Female PT (BSPT) taper thread, both ends
- Other threads
- NPT made to order
- Pressure
- Class 150
- Port
- Full coupling, same size both ends; 3/4″ also in 20L and 30L body lengths
Where it gets used
Every fitting checked for size and thread.
Each fitting is checked for dimensions and thread before shipment.
What is the difference between a coupling and a union?
A coupling is a one-piece sleeve: to take it out you unscrew the pipe. A union splits into three parts so the line can be opened without turning the pipe. Use a coupling on runs you do not expect to open and a union where you will service the line.
Is this a full coupling or a half coupling?
A full coupling: both ends are threaded at the same size. A half coupling has one threaded end and one plain end for welding onto a pipe or vessel.
What thread is it?
Female PT taper thread on both ends. PT is the same 55° taper thread as BSPT and Rc. If your line is NPT, tell us with the inquiry; NPT is made to order.
Should I choose 304 or 316?
304 for water, air and general service. 316 where chlorides are present: brine, coastal sites, washdown, most chemicals. Keep the whole threaded run in one grade.
What sizes can I order?
1/8″, 1/4″, 3/8″, 1/2″, 3/4″, 1″, 1-1/4″, 1-1/2″, 2″, 2-1/2″, 3″ and 4″, the same size on both ends. The 3/4″ size is also made in 20L and 30L body lengths. Mixed sizes in one order are fine.
Do you make the matching fittings?
Yes. Hex nipples, 45° and street elbows, caps, crosses, unions and the rest of the threaded stainless range in the same grades and sizes. Send one take-off list and we quote it as one.
