ISO 9001:2015IBR ApprovedEstablished 1971Full Material Traceability
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Threaded Plug — OEM manufacturer, Teshi Group

OEM manufacturer ASME B16.11 · ASME B1.20.1

Threaded Plugs — Hex, Square & Round Head, ASME B16.11

A threaded plug screws into a female-threaded opening to close it. Teshi Group manufactures hex head, square head and round head plugs to ASME B16.11, with NPT threads to ASME B1.20.1, in carbon, low-temperature, alloy and stainless steels.

Also called: hex head plug, square head plug, round head plug, pipe plug, NPT plug

StandardASME B16.11
Pressure classNot class-designated in ASME B16.11
Size rangeNPS ⅛"–4" (DN 6–100) per ASME B16.11

What is a Threaded Plug?

A threaded plug is a forged or bar-machined fitting with a male taper thread and a head for tightening. Hex head plugs are tightened with a spanner and are the most common; square head plugs are used where a square drive is preferred; round head plugs have no flats and are typically seal welded or used where tampering should be discouraged. Plugs close tee outlets, couplings, threadolets, valve drains and vents. ASME B16.11 covers plugs without a pressure class designation.

Key features

  • Hex head, square head and round head per ASME B16.11
  • NPT male thread per ASME B1.20.1, gauged
  • Solid forged or bar-machined body
  • Closes female-threaded outlets on fittings, valves and equipment

Specification

SupplyOEM manufacturer — Teshi Group, India, India
StandardASME B16.11
TypesHex head, square head, round head
Pressure classNot class-designated in ASME B16.11
Size rangeNPS ⅛"–4" (DN 6–100) per ASME B16.11
ThreadsNPT per ASME B1.20.1; BSPT (ISO 7-1) on request
Materials — carbon & low-temp steelASTM A105; ASTM A350 LF2 Cl.1
Materials — alloy steelASTM A182 F11 Cl.2, F22 Cl.3, F5, F9, F91
Materials — stainless & duplexASTM A182 F304, F304L, F316, F316L, F321; F51, F53 duplex
TestingVisual, dimensional and thread/socket gauge inspection; PMI on alloy and stainless grades; hardness check; MPI/DPT when specified
DocumentsEN 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

  • Closing tee, coupling and threadolet outlets
  • Valve body drains and vents
  • Test points and spare tappings
  • Pump and equipment casing connections

FAQ

Threaded Plug: common questions

Which plug type should I choose?

Hex head plugs are the common choice because they are easy to tighten. Square head plugs suit square drives; round head plugs are used where the plug will be seal welded.

Do plugs have a pressure class?

ASME B16.11 does not assign class designations to plugs and bushings. Select the plug material to match the fitting, valve or equipment it closes, as per the piping specification.

Can plugs be supplied in the same material as the valve?

Yes. Plugs are supplied in ASTM A105, A350 LF2, A182 F11, F22, F304L, F316L and duplex grades to match the parent fitting or valve body.

How should the plug be sealed?

Use a thread sealant or PTFE tape suited to the service on NPT threads and tighten to normal make-up. For hazardous, cyclic or high-temperature service, many piping specifications require threaded joints to be seal welded.

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 specification

Traceability

From mill heat to your site

  1. 01

    Approved mill material

    Received against the mill certificate; heat number registered.

  2. 02

    Forging & machining

    Heat number carried through every stage in our Indian works.

  3. 03

    PMI, dimensional & NDT

    Every lot inspected to the governing standard; TPI witness on request.

  4. 04

    Stamped & certified dispatch

    Hard-stamped pieces with EN 10204 3.1 / 3.2 certificates.

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