Pipes & Fittings

Weldolets, olets and forged fittings

Branch outlets and small-bore forged fittings make up a large share of the line items on any piping bill of materials. CRS PLUS sources weldolets, sockolets and thredolets to MSS SP-97, socket-weld and threaded fittings to ASME B16.11, and the pipe nipples, swage nipples and plugs that go with them.

Items we quote

Sourced through the qualified supplier base. Sizes, ratings and grades are shown as ranges; send your bill of materials and every line is quoted against its exact specification.

Items we quote
Product	Standard	Sizes	Rating / class	Materials
Weldolet (butt-weld outlet)	MSS SP-97	Outlet NPS ⅛ to 24	STD, XS, Sch 160, XXS	A105N, A350 LF2, A182 F304L / F316L
Sockolet (socket-weld outlet)	MSS SP-97	Outlet NPS ⅛ to 4	Class 3000, 6000	A105N, A350 LF2, A182 stainless
Thredolet (threaded outlet)	MSS SP-97	Outlet NPS ⅛ to 4	Class 3000, 6000	A105N, A350 LF2, A182 stainless
Elbolet, latrolet, nipolet	MSS SP-97	Outlet NPS ¼ to 2	Class 3000, 6000	A105N, A182 stainless
Socket-weld elbow, tee, coupling, cap	ASME B16.11	NPS ⅛ to 4	Class 3000, 6000, 9000	A105N, A350 LF2, A182 stainless
Threaded elbow, tee, coupling, union, plug, bushing	ASME B16.11 / MSS SP-83	NPS ⅛ to 4	Class 2000, 3000, 6000	A105N, A350 LF2, A182 stainless
Pipe nipple (PBE, BBE, TBE, TOE)	ASME B36.10 pipe	NPS ⅛ to 4	Sch 80, 160, XXS	A106 B, A333 Gr 6, A312 stainless
Swage nipple and bull plug	MSS SP-95	NPS ¼ to 12	Sch 40 to XXS	A105N, A234 WPB, A182 stainless

Matching class to schedule

ASME B16.11 forged fittings are rated by class rather than schedule, and each class is paired with a pipe wall. For socket-weld fittings, class 3000 matches Sch 80, class 6000 matches Sch 160 and class 9000 matches XXS. For threaded fittings, class 2000 matches Sch 80, class 3000 matches Sch 160 and class 6000 matches XXS. A request such as "¾ in 6000# nipple" therefore describes a heavy-wall nipple intended to work with 6000-class fittings, and the quotation confirms the schedule supplied.

How an olet is specified

An olet is identified by its outlet size and rating and by the run pipe it sits on — for example "Weldolet 2 in × 6–8 in run, XS, A105N". The run size matters because the base of the olet is contoured to the outside diameter of the header pipe. Weldolets are butt-welded to the branch pipe; sockolets and thredolets take socket-weld or threaded small-bore connections, typically for instruments, vents and drains.

Documentation and supply terms

Mill test certificate: EN 10204 3.1 certificate for every line, traceable to the heat number marked on the item. EN 10204 3.2 with third-party witness on request.
Marking: Material grade, size, rating and heat number marked on each item to the governing standard (MSS SP-25 for valves, flanges and fittings).
Inspection: Positive material identification, dimensional checks and third-party inspection arranged where the project specifies them.
Sour and low-temperature service: NACE MR0175 / ISO 15156 hardness limits and impact testing applied where the piping class calls for them, and stated on the certificate.
Quotation: Each line states the standard, grade, origin, lead time and certification before you commit. Listing does not indicate stock held by CRS PLUS.

Frequently asked questions

What is a weldolet?

A weldolet is a forged branch fitting welded onto a run pipe to create a butt-weld outlet. It provides integral reinforcement, so a branch can be taken off a header without a reinforcing pad or a full tee. Weldolets are made to MSS SP-97.

What is the difference between a weldolet, sockolet and thredolet?

All three are welded to the run pipe; they differ at the outlet. A weldolet has a bevelled end for a butt weld, a sockolet has a socket for a socket-weld connection and a thredolet has an internal NPT thread.

What do PBE, BBE and TBE mean on a pipe nipple?

They describe the end preparation: PBE is plain both ends, BBE is bevelled both ends, TBE is threaded both ends and TOE is threaded one end. The length and schedule are stated with the end type.

What is a swage nipple?

A swage nipple is a forged reducing nipple, concentric or eccentric, made to MSS SP-95. It joins pipes of different sizes in small-bore lines and is often specified with one end bevelled and one end threaded or plain.

Are these fittings supplied with certificates?

Yes. Each fitting is marked with material, class and heat number and supplied with an EN 10204 3.1 mill test certificate. Sour-service, low-temperature or third-party inspection requirements are taken from your specification and stated on the quotation.

Request an olets and forged fittings quotation

A structured offer follows within 72 hours.