Industrial range
Pipe nipples, swage nipples and bull plugs
Short lengths and reducers for small-bore piping: pipe nipples, swage nipples that change size between two end types, and bull plugs that close a line, all rated as the pipe they match.
A pipe nipple is a short length of pipe with threaded, plain or beveled ends; a swage nipple is a forged or pipe-formed reducer that changes from one pipe size to another, with its own end type at each size; a bull plug is a domed closure for the end of a pipe. Nipples are made to ASTM A733, and swage nipples and bull plugs to MSS SP-95, which rates them as seamless pipe of the same material and wall. We supply all three in carbon, alloy and stainless steels, with NPT, plain, beveled or grooved ends.
Swage nipples
| Option | Choices |
|---|---|
| Shape | Concentric or eccentric |
| Size range | NPS 1/4 to 12, any reduction the standard allows |
| Ends, each size | Threaded NPT, plain (square cut), beveled for butt welding, grooved |
| Wall, each end | By schedule, for example Schedule 160 by Schedule 80, to XXS |
| Rating | As seamless pipe of the same material and wall, under ASME B31.1 or B31.3 |
Ranges and rating basis per MSS SP-95. Ends are written small end first, for example TSE x BLE: threaded small end by beveled large end.
Pipe nipples
| Type | What it is |
|---|---|
| Close | Threaded its whole length, the shortest nipple for a size |
| Short and long | Threaded ends with plain pipe between; lengths to order |
| TBE, TOE, PBE, BBE | Threaded both ends, threaded one end, plain both ends, beveled both ends |
Pipe nipples to ASTM A733, from seamless or welded pipe of the ordered schedule. Threads are NPT to ASME B1.20.1.
Bull plugs
Bull plugs close the end of a line with a domed head that carries pressure better than a flat cap. MSS SP-95 covers them from NPS 1/8 to 12 with threaded, plain or beveled ends. A bull plug can be drilled and tapped, usually 1/2 in NPT, for a gauge, a bleed valve or a thermowell.
For hammer union ends on flowline iron, see union crossovers, bull plugs and lift subs.
Materials and documents
Nipples and swages are made from ASTM A106 Grade B seamless pipe or A105 forgings, A350 LF2 for low temperatures and F304 or F316 stainless, and in AISI 4130 for 4130 lines, heat treated to your order. Each piece is marked with size, schedule, material and heat number and certified to EN 10204 3.1.
Ordering
Swage nipple, concentric, NPS 2 x 1, large end Schedule 160 beveled (BLE), small end XXS threaded NPT (TSE), ASTM A105, MSS SP-95, EN 10204 3.1, 20 pcs
Bull plug, NPS 2, Schedule 160, threaded NPT, tapped 1/2 in NPT, ASTM A105, MSS SP-95, EN 10204 3.1, 10 pcs
Frequently asked questions
What do TBE, TOE and PBE mean?
They describe the ends: threaded both ends (TBE), threaded one end with the other plain (TOE), plain both ends (PBE) and beveled both ends (BBE). Swage nipples add the end at each size, for example threaded small end by beveled large end.
How is a swage nipple rated?
MSS SP-95 rates a swage nipple as seamless pipe of the same material and wall under the applicable piping code, such as ASME B31.1 or B31.3. Order the wall by schedule at each end, for example Schedule 160 by Schedule 80.
Concentric or eccentric?
A concentric swage keeps both ends on one centerline. An eccentric swage keeps one side flat, used on horizontal lines to avoid trapping air at the top or liquid at the bottom.
Can a bull plug take a gauge?
Yes. A bull plug can be drilled and tapped, usually 1/2 in NPT, for a gauge, a bleed valve or a thermowell. Give the tapping size and position.