What is a threaded union?
The stainless threaded union joint consists of three parts – a nut, a female end, and a male end.
To make the stainless threaded union fitting work properly, both male and female ends are secured together with nuts.
Usually, two types of threaded union are offered F/F and F/M.
The female threaded union fitting has threads on the inside, while the threads are on the outside of the male threaded fitting. The male/female threaded union has a male connection end and one female threaded connection end.
Specification of THD union
THD type | NPT PT BSPP BSPT PF |
size range | 1/8″-3″/DN6-80 |
Pressure rating | Class 3000lbs |
Standard | Mss Sp83 |
Carbon Steel | ASTM A150/A150N |
Low Tem Carbon Steel | ASTM A350 LF2/LF3 |
Pipeline Steel | ASTM A694 F42/46/56/60/65 |
Alloy Steel | ASTM A182 F11/F12/F5/F9/F91/F92 |
Stinless Steel | ASTM A182 F304/304L/304H,316,316L,310S,317,347,904L |
Advantages of THD union
They are reliable.
Less force is required to tight a joint because of the mechanical advantage offered by spanner.
They have small overall dimensions and are compact in construction.
Threads have self-locking property hence they can be used in any position either vertical or horizontal