OEM manufacturer ASME B16.11 · ASME B1.20.1
Threaded Caps — ASME B16.11
A threaded cap screws onto the male-threaded end of a pipe or nipple to close it. Teshi Group manufactures threaded caps to ASME B16.11 in Class 3000 and 6000, with NPT threads to ASME B1.20.1.
Also called: screwed cap, NPT cap, forged threaded end cap, female threaded cap, pipe cap threaded
What is a Threaded Cap?
A threaded cap is a forged fitting with a female thread and a closed end. It screws over a male pipe or nipple end and can be removed for draining, venting or extending the line. A plug does the same job for a female-threaded opening. Caps are used on drains, vents, test points and spare connections in small-bore piping. Caps are ordered by size, class and material to match the pipe.
Key features
- Forged body per ASME B16.11
- Class 3000 and 6000
- NPT female thread per ASME B1.20.1
- Removable closure for male pipe ends
Specification
| Supply | OEM manufacturer — Teshi Group, India |
|---|---|
| Standard | ASME B16.11 |
| Pressure class | Class 3000 and 6000 |
| Pipe compatibility | Class 3000 → Sch 160, Class 6000 → XXS pipe |
| Size range | NPS ⅛"–4" (DN 6–100) per ASME B16.11 |
| Threads | NPT per ASME B1.20.1; BSPT (ISO 7-1) on request |
| Materials — carbon steel | ASTM A105 / A105N; ASTM A181 Cl 60, Cl 70; ASTM A266 Gr 2, Gr 4 (large forgings) |
| Materials — high-yield carbon steel | ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 (MSS SP-44 grades F52–F70) |
| Materials — low-temperature carbon steel | ASTM A350 LF1, LF2 Cl 1, LF2 Cl 2, LF3, LF6, LF9 |
| Materials — alloy steel (Cr-Mo) | ASTM A182 F1, F2, F5, F5a, F9, F11 Cl 1 / 2 / 3, F12 Cl 1 / 2, F21, F22 Cl 1 / 3, F22V, F91, F92, F911; ASTM A336 F11, F22 (large forgings) |
| Materials — stainless steel | ASTM A182 F304, F304L, F304H, F304LN, F309H, F310, F316, F316L, F316H, F316LN, F316Ti, F317, F317L, F321, F321H, F347, F347H, F348 |
| Materials — 904L and 6Mo | 904L (ASTM A182 F904L, UNS N08904); 254 SMO / 6Mo (ASTM A182 F44, UNS S31254); AL-6XN (ASTM A182 F62, UNS N08367) |
| Materials — duplex stainless steel | ASTM A182 F51 (UNS S31803), F60 (UNS S32205, 2205) |
| Materials — super duplex stainless steel | ASTM A182 F53 (UNS S32750, 2507), F55 (UNS S32760), F61 (UNS S32550) |
| Materials — nickel alloys | ASTM B564 / B160 / B462: Nickel 200 / 201 (N02200 / N02201), Monel 400 (N04400), Monel K-500 (N05500), Inconel 600 (N06600), Inconel 625 (N06625), Inconel 718 (N07718), Incoloy 800 / 800H / 800HT (N08800 / N08810 / N08811), Incoloy 825 (N08825), Hastelloy C276 (N10276), Hastelloy C22 (N06022), Hastelloy B2 / B3 (N10665 / N10675), Alloy 20 (N08020) |
| Materials — titanium | ASTM B381 Grade F1, F2, F5 (Ti-6Al-4V), F7, F12 |
| Materials — copper-nickel | Cu-Ni 90/10 (UNS C70600) and 70/30 (UNS C71500), ASTM B151 bar; flanges to ASME B16.5 or EEMUA 145 |
| Grade availability | Every grade listed is made or supplied against order, with EN 10204 3.1 certificates (3.2 / third-party inspection when specified) and PMI on alloy, stainless, duplex and nickel grades. |
| Testing | Visual, dimensional and thread/socket gauge inspection; PMI on alloy and stainless grades; hardness check; MPI/DPT when specified |
| Documents | EN 10204 3.1 mill test certificate; 3.2 / third-party inspection when the order specifies; dimensional inspection report; IBR certification for boiler/steam service when specified |
Applications
- Drain and vent ends
- Test and spare connections
- Instrument line ends
- Utility piping
Threaded cap vs threaded plug
A threaded cap has a female thread and closes a male-threaded pipe or nipple end. A threaded plug has a male thread and closes a female-threaded opening such as a tee outlet, coupling, threadolet or valve drain. Choose by the gender of the end that needs closing, and match the material and class to the piping specification. Both can be removed later for draining, venting or extending the line.
FAQ
Threaded Cap: common questions
What is the difference between a cap and a plug?
A cap has a female thread and screws onto a male pipe or nipple end. A plug has a male thread and screws into a female opening. Both are covered by ASME B16.11.
Which class should I order?
Match your piping specification. Class 3000 threaded caps are rated for use with Sch 160 pipe and Class 6000 caps with XXS pipe of equivalent material.
Can threaded caps be seal welded?
Yes, where the piping specification requires it. Seal welding should follow the piping code and a qualified welding procedure for that material, with thread compound kept off the weld area.
What documents are supplied?
An EN 10204 3.1 mill test certificate is supplied as standard. EN 10204 3.2 or third-party inspection, and IBR certification for boiler or steam service, are provided when the order specifies them.
Need a size or grade not listed here?
Our engineering team manufactures against your drawing or datasheet, with dimensional sign-off before dispatch.
Send us your specificationTraceability
From mill heat to your site
- 01
Approved mill material
Received against the mill certificate; heat number registered.
- 02
Forging & machining
Heat number carried through every stage in our Indian works.
- 03
PMI, dimensional & NDT
Every lot inspected to the governing standard; TPI witness on request.
- 04
Stamped & certified dispatch
Hard-stamped pieces with EN 10204 3.1 / 3.2 certificates.
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