Tesco Steel & Engineering forges weldolets — the integrally reinforced 90° branch outlet that puts a full-strength branch on a header with two butt welds and no reinforcing pad: the compensation the piping code demands around a branch opening is forged into the fitting's own body per MSS SP-97, the base contoured to the run-pipe curvature, the top bevelled to meet the branch like any butt-weld joint. We make them in NPS ¼″ to 48″ (DN 8–1200), schedules STD, XS, XXS and Sch 160, full-size and reducing, and — the point of buying them from a flange forge — in every material grade on this site: carbon steel A105, LTCS LF2, the chrome-moly ladder, stainless, duplex and the nickel alloys. Each piece is laser-marked with grade, run × branch, schedule and heat number, PMI-checked on alloy grades, and certified to EN 10204 3.1/3.2. The full dimension tables — every schedule, heights, base ODs and weights — are in the datasheet below. ISO 9001:2015, made in Mumbai, India — exported to 50+ countries.
A350 LF2 Weldolet, 24″ × 3″ Sch 100 × Sch 160 — Laser-Marked at Our Mumbai Works
What is a Weldolet?
The self-reinforced branch connection. A weldolet (also written welding outlet, or just WOL) is a forged, integrally reinforced fitting that makes a 90° branch on a run pipe: its contoured base is butt-welded over a cut opening in the header, its bevelled top is butt-welded to the branch pipe, and the reinforcement the code requires around the opening is already in the forging — no pad, no saddle. Governing standard MSS SP-97; branch logic per ASME B31.3/B31.1. We forge them NPS ¼″–48″, STD to Sch 160, full-size and reducing, in every grade from A105 to Hastelloy, laser-marked and certified to EN 10204 3.1/3.2.
The trade is honest: a forged outlet costs more per piece than a plate pad — and buys back its price in fewer weld lines, no hidden crevice, cleaner NDT and a branch whose strength came out of a forge rather than out of a fit-up. That arithmetic is why hydrocarbon and steam specifications write olets by default.
The Olet Family — Same Body, Different Ends
Fitting
Branch Connection
Typical Duty
Weldolet (this page)
Butt-weld bevel
The default 90° branch — any size, any butt-welded line
The code's compensation for the cut opening is in the body profile — MSS SP-97 geometry sized so the finished branch meets B31.3's area-replacement logic without a pad, a saddle or a calculation redone at the fit-up stage.
Contoured to Your Header, Not a Generic Curve
Each outlet is machined for a stated run range — saddle-curved for the header sizes you name, flat-based for 36″ and up — so the base groove weld starts from a fit, not from grinding.
The Whole Grade Bench, One Enquiry
A105 to Hastelloy from the same forge that makes this site's flanges — the branch fitting inherits the line's metallurgy, its PMI, and its paperwork habits, on one purchase order.
Traceability You Can Read Off the Part
Laser marking with grade, run × branch, schedules and heat number — the photographs on this page are production pieces, and the marking on them is the certificate's visible end.
Specification Notes — Getting Weldolets Right
Three honest notes.The outlet supplies geometry; the designer owns the calc: MSS SP-97 gives the fitting its rating basis, but branch reinforcement on your line is the piping engineer's B31.3 check — state the code and class and the two meet cleanly. Severely cyclic and large-bore branches read the sweepolet: where stress intensification and fatigue drive the design, the swept contour earns its bigger forging — ask, and we quote both. And state the run range, not just the branch: one 6″ outlet curved for a 12″ header will not sit on a 30″ one — run × branch on the enquiry saves a re-machining round trip.
How Our Weldolets Are Manufactured
1
Material — certified forgings in the ordered grade, heat treated as the grade demands — normalised LF2, N&T chrome-moly, solution-annealed stainless and duplex — with furnace records retained; heat-number transfer at the first operation.
2
Body machining — the MSS SP-97 profile turned to size: height, base OD and the reinforcement contour that is the fitting's whole purpose.
3
Saddle contouring — the base machined to the stated run range — curved to the header OD, or flat-based for large runs — so the groove weld starts from metal-to-metal fit.
4
Bore & bevel — bore matched to the branch schedule, top end bevelled for the butt weld; bevel angle and root face checked against the datasheet dimensions.
5
Testing & marking — PMI on alloy grades, MPI/DPT/UT/RT to the ordered scope, dimensions verified, then laser marking: grade, run × branch, schedule, heat number.
6
Certification & packing — EN 10204 3.1 MTC (3.2 witnessed on request) tying every piece to its heat; bevels protected, packed sea-worthy.
Where Weldolets Are Used
Wherever a header needs a branch and a tee would be overkill: refinery and petrochemical process headers — instrument takeoffs, vents, drains and secondary lines — power-station steam and feedwater systems in the chrome-moly grades, oil and gas gathering and transmission at every metering and blowdown point, and utility air, nitrogen and water services by the crate in carbon steel. Production pieces below — the marking on each is real:
How to read the table: height A is measured installed, from the run-pipe outside surface to the branch weld end; B is the outside diameter of the outlet base at the run; C is the bore. Common STD sizes below — the full datasheet (PDF) carries all 28 STD sizes plus the complete XS, XXS and Sch 160 tables with unit weights.
Branch NPS
DN
Height A (mm)
Base OD B (mm)
Bore C (mm)
Weight (kg)
½″
15
19.05
34.93
23.81
0.08
¾″
20
22.23
44.45
30.16
0.11
1″
25
26.99
53.98
36.51
0.23
1½″
40
33.34
73.03
50.80
0.45
2″
50
38.10
88.90
65.09
0.79
3″
80
44.45
122.24
93.66
1.81
4″
100
50.80
152.40
120.65
2.86
6″
150
60.33
215.90
169.86
6.44
8″
200
69.85
263.53
220.66
10.66
Schedules STD, XS, XXS and Sch 160 are stocked; other schedules, special heights and non-standard contours are machined to drawing with dimensions confirmed on the order.
How to Specify & Order a Weldolet
Six elements — run × branch is the one people forget:
1
Run × branch — e.g. 12″ × 3″, or the run range one outlet should cover across several headers.
2
Branch schedule — STD, XS, XXS or Sch 160, matched to the branch pipe wall.
3
Material grade, exactly — A105, A350 LF2, A182 F316L dual-certified, F51... as your specification writes it.
4
Design code where it helps — B31.3 or B31.1 confirms bevel and documentation expectations.
5
Certification & NDT — EN 10204 3.1 (our standard) / 3.2 witnessed; MPI, DPT, UT or RT scope if extended.
Example: “Weldolet, 14″ × 6″, Sch 10S × Sch 40S, ASTM A182 F316L dual-certified, B31.3, EN 10204 3.1, MPI on bevels — 8 pieces.” Quotations normally within 24 hours with price, unit weights and delivery.
Weldolets — Frequently Asked Questions
What is a weldolet (welding outlet)?
A weldolet is a forged, integrally reinforced branch outlet fitting that makes a 90° branch connection on a pipe: its contoured base is butt-welded onto the run (header) pipe over a cut opening, and its bevelled top end is butt-welded to the branch pipe. The reinforcement that piping codes demand around a branch opening is forged into the fitting's own body, so no reinforcing pad or saddle is needed — one fitting, two butt welds, full strength. The industry also calls it a welding outlet, branch outlet or simply WOL, and the governing standard is MSS SP-97. We forge weldolets in NPS ¼" to 48", schedules STD to Sch 160, full-size and reducing, in every material grade on this site — carbon steel to nickel alloys — each laser-marked and certified to EN 10204 3.1/3.2.
Why use a weldolet instead of a stub-in branch with a reinforcing pad?
Because the reinforcement is forged in, not welded on. A stub-in branch cuts a hole in the header and welds the branch pipe straight into it; the metal removed must then be compensated, usually by a reinforcing pad — a second component with two more weld lines, a hidden surface that traps moisture, and a vent hole to test. A weldolet replaces all of that with one forged body whose thickness profile already carries the compensation: fewer welds, no hidden crevice, cleaner inspection, and a fitting whose pressure rating comes from the forging rather than from field fabrication quality. The trade is cost per piece against fabrication labour and inspection risk — which is why specifications for hydrocarbon, steam and cyclic services overwhelmingly write olets for small and mid-size branches, and why designers reach for stub-ins mainly on low-pressure utility duty.
What standard covers weldolets?
MSS SP-97 — Integrally Reinforced Forged Branch Outlet Fittings — is the manufacturing standard: it defines the fitting classes, the pressure-temperature basis, marking and materials cross-references for butt-weld, socket-weld and threaded outlets. The branch-end weld bevel follows the buttweld conventions the branch pipe expects, and the reinforcement logic that lets the fitting replace a calculated pad comes from the piping code the line is built to — ASME B31.3 for process work, B31.1 for power. Materials are supplied to their own product standards: ASTM A105 for carbon steel, A350 LF2 for low-temperature duty, A182 for the alloy, stainless and duplex grades, and B564 for the nickel alloys — so a weldolet's certificate reads like a forging certificate, because that is what it is. State the code your line is designed to and the paperwork follows it.
What sizes and schedules do weldolets come in — and what is a run range?
Branch sizes run NPS ¼" through 48" (DN 8 to DN 1200), in schedules STD, XS, XXS and Sch 160 matched to the branch pipe wall. The useful subtlety is the run range: a weldolet's base is contoured as a saddle, and one contour fits a whole span of header diameters — a 6" branch outlet might be machined flat-based for 36" and larger runs, or curved for a stated range like 12"–16". That is why an enquiry states both numbers, run × branch — the 24" × 3" LF2 outlet photographed on this page reads exactly that way on its laser marking — and why our quotation confirms the run range each piece is contoured for. Reducing combinations are the everyday order; full-size (equal) outlets are the special case. The complete dimension tables — height A, base OD B and bore C for every schedule — are in the datasheet downloadable on this page.
What materials are weldolets available in?
Every grade this site forges flanges in. Carbon steel A105 for general process and utility duty; A350 LF2 for impact-tested low-temperature service; the chrome-moly ladder A182 F11, F22, F5, F9 and F91 for steam and hot hydrogen circuits; stainless A182 F304/F304L, F316/F316L, F321 and F347 with dual certification where heats qualify; duplex F51 and the super duplex pair F53/F55 for chloride duty; and the nickel bench — Monel 400, Inconel 600/625, Incoloy 800/825, Hastelloy C-276 — plus 90/10 and 70/30 copper-nickel and titanium against specific enquiry. The branch outlet takes the same metallurgical decisions as the flanges on the line: the material pages across this site tell each grade's story, and a weldolet order simply names the grade alongside run × branch × schedule. Chemistry per heat, PMI on alloy grades, EN 10204 3.1/3.2 on every lot.
How is a weldolet welded to the pipe?
In two distinct welds. The base weld attaches the outlet to the run pipe: the header is cut open using the outlet's bore as the template, the saddle is set over the opening, and a full-penetration groove weld — usually finished with a fillet cover pass — joins the forged body to the header all round. The branch weld is an ordinary butt weld: the outlet's bevelled top meets the branch pipe like any B16.25-style joint. Welding discipline follows the material, exactly as on the rest of this site: carbon steel welds simply, chrome-moly outlets carry preheat and PWHT per the line's qualified procedure, stainless takes purge and low-carbon filler, duplex holds its heat-input window. The base weld is the one inspectors watch — MPI or DPT between passes on alloy work, UT or RT where the specification calls for it — because it is the weld that turns a header and a forging into a branch connection.
Weldolet, sockolet or threadolet — which outlet fits the job?
They share the same forged, integrally reinforced body; the branch-end connection is the difference. A weldolet ends in a butt-weld bevel and suits any size — it is the only choice above NPS 2 and the default wherever the line is butt-welded. A sockolet ends in a socket: the branch pipe slips in and is fillet-welded, the small-bore convenience for instrument and drain connections. A threadolet ends in a tapered thread — NPT or BSPT — for lines that must break by hand. The rest of the family answers geometry rather than connection: elbolets sit on elbows, latrolets make 45° branches, nipolets carry an integral nipple, sweepolets contour into the run for large-bore, low-stress-concentration work, and flangeolets end in a flange — that one already has its own page here, and the others are joining it. State connection type, run × branch and schedule, and the outlet picks itself.
When does a sweepolet make more sense than a weldolet?
When stress concentration matters more than simplicity. A weldolet is compact and its base weld is straightforward, but the geometry transitions quickly from header to branch — perfectly acceptable for the vast majority of process branches. A sweepolet spreads the same integral reinforcement into a long, swept contour that flows into the run pipe, cutting the stress intensification factor at the crotch — which is why transmission pipelines, large-bore headers and severely cyclic systems specify it, accepting a bigger forging and a longer weld in exchange. The honest rule: if your stress engineer is quoting SIFs and fatigue cycles, the conversation includes sweepolets; if the branch is a routine process connection, the weldolet is the economical, code-satisfying answer. We quote both — a sweepolet page is on its way to this menu, and enquiries for either are answered from the same forge.
Is 'Weldolet' a brand name?
Historically yes — Weldolet, along with Sockolet, Thredolet and several other -olet names, originated as trademarks of Bonney Forge, the American firm that developed the fittings. Decades of use have made the words the everyday generic vocabulary of the piping trade worldwide, the way engineers say them on site and write them in requisitions, and this page uses them in that ordinary generic sense. What we manufacture and certify are integrally reinforced forged branch outlet fittings to MSS SP-97 — that is the wording on our certificates — dimensionally and functionally interchangeable with any outlet made to the same standard. If your procurement documents say 'welding outlet', 'branch outlet fitting', 'WOL' or 'olet', they mean this product; state the standard and the certificate will carry it.
What is marked on each weldolet?
Manufacturer, material grade, size as run × branch (or branch alone on flat-based large-run outlets), schedule and heat number — laser-marked on the machined body, exactly as the photographs on this page show: a 24" × 3" A350 LF2 outlet reads its grade, both sizes, both schedules and its heat number in one line, and a 2" × 6" duplex 2205 pair carries the TESCO mark beside the heat. The marking is the traceability chain's visible end: the heat number ties the piece to its EN 10204 certificate, the certificate to the mill heat, and PMI on alloy grades confirms the metal matches the mark before anything ships. Where a project requires additional marking — tag numbers, PO references, colour coding — it is applied to order and recorded on the documentation.
What testing and certification come with weldolets?
The forging's full paper trail. Chemistry and mechanicals are certified per heat on the EN 10204 3.1 MTC — 3.2 witnessed by your inspector or a third party on request — with heat treatment condition and furnace records where the grade demands them: normalised for LF2, N&T for the chrome-moly rungs, solution annealed for stainless and duplex. PMI verifies alloy grades piece by piece. Non-destructive examination is quoted to the specification: MPI or DPT of the machined surfaces and weld bevels, UT of the forging, RT where a project extends it, and hardness testing where sour-service or code limits apply. Dimensional inspection covers height, base OD, bore and bevel angle against MSS SP-97 and the datasheet tables. Third-party inspection — witness or review — is routine on project orders; state the agency and scope on the enquiry.
Where are weldolets used?
Anywhere a pipe needs a full-strength 90° branch without a tee. Refineries and petrochemical plants branch instrument takeoffs, vents, drains and secondary process lines off headers with them; power stations use them across steam and feedwater systems, in chrome-moly grades on the hot circuits; oil and gas gathering and transmission systems fit them at every metering and blowdown point; and utility piping — air, nitrogen, cooling water — uses carbon steel outlets by the crate. The pattern of use is consistent: wherever cutting in a tee would mean two butt welds in the main line and a fitting the size of the header, an olet gives the same code-compliant branch with the header cut once and the fitting sized to the branch. Our order book runs from single alloy pieces for shutdown repairs to project lots of several hundred carbon steel outlets.
Where can I find weldolet dimensions?
In the datasheet on this page — a three-page PDF with the complete dimension tables for every schedule we stock: STD in 28 sizes, XS, XXS in 13 sizes and Sch 160 in 13 sizes, each listing NPS and DN designations, height A from the run-pipe surface to the branch weld end, base outside diameter B, bore C and unit weight. The page above reproduces the common STD sizes for quick reference. Two reading notes: height A is measured installed — from the header's outside surface — so stack-up calculations use it directly; and the base OD B governs the clearance you need between adjacent branches on a crowded header. For non-standard schedules, special contours or heights, we machine to drawing and confirm dimensions on the order — the datasheet covers the standard range.
What details are needed to get an accurate weldolet quotation?
Six elements plus commercial terms: (1) run × branch size — e.g. 12" × 3", or the run range where you want one outlet covering several headers; (2) branch schedule — STD, XS, XXS or Sch 160, matched to your branch pipe; (3) material grade, stated exactly as your specification writes it — A105, A350 LF2, A182 F316L dual-certified, F51, and so on; (4) the design code where it helps — B31.3 or B31.1 confirms bevel and documentation expectations; (5) certification and NDT — EN 10204 3.1 (our standard) or 3.2 witnessed, plus MPI/DPT/UT/RT scope if your specification extends it; (6) quantity and destination. Attach the line list or isometric extract if one exists — reading run and branch straight off the drawing removes a whole class of errors. Quotations normally return within 24 hours with price, unit weights and delivery.
Who manufactures weldolets in India?
Tesco Steel & Engineering is an ISO 9001:2015 certified manufacturer based in Mumbai, India, forging integrally reinforced branch outlet fittings to MSS SP-97 — weldolets (welding outlets) in NPS ¼" to 48", schedules STD to Sch 160, full-size and reducing, contoured to the customer's run range. Materials span our whole forge: carbon steel A105, LTCS A350 LF2, chrome-moly A182 F11 through F91, stainless 304/316/321/347 families, duplex F51/F53/F55 and the nickel alloys, with PMI verification and EN 10204 3.1/3.2 certification on every lot and laser marking tying each piece to its heat. The same works supplies the complete olet family — sockolets, threadolets, elbolets, nipolets, latrolets, sweepolets and flangeolets — alongside the flange ranges this site is built around. Exported to more than 50 countries; datasheet with full dimension tables downloadable on this page.
