Flangeolet Manufacturer

Tesco Steel & Engineering manufactures flangeolets (flangeolet / nipoflange) — a one-piece, self-reinforced branch outlet that combines an olet (branch connection) and a flange in a single forging. It welds onto the run (header) pipe like a weldolet and presents a finished flanged face for the branch, so a flanged branch is made with one fitting and one weld instead of an olet, a stub, and a separate flange. Made to MSS SP-97 in A105, SS 304/316/321, Monel, Inconel, and Incoloy. Class 150 to 2500 and PN6 to PN400. ISO 9001:2015 certified. Made in India.

Self-Reinforced Branch Olet + Flange in One MSS SP-97 One Fitting, One Weld A105 / SS 316 / Monel / Inconel Class 150–2500 · PN6–PN400 RF / RTJ Facing ISO 9001:2015

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Flangeolet A105 SS 304 316 321 Inconel Monel

Flangeolet (Nipoflange)

What Is a Flangeolet?

Definition: A Flangeolet (also called a nipoflange or weldoflange) is a self-reinforced branch outlet fitting that integrates an “olet” branch connection with a flange in one forging. One end is contoured to sit on and weld to the run (header) pipe; the other end is a finished flange face ready to bolt to the branch line. This lets a flanged branch be taken off a header with a single fitting and a single weld, instead of welding a weldolet/nipolet to the pipe, adding a stub, and then welding on a separate flange. The fitting is integrally reinforced (it satisfies the branch area-replacement rule without a pad), making it strong, compact, and quick to install. A flangeolet is the branch equivalent of a long weld-neck flange and is made to MSS SP-97, the standard for forged integrally-reinforced branch outlet fittings.

Flangeolets save a weld, a stub, and fabrication time on branch and instrument connections off headers. Tesco Steel & Engineering supplies flangeolets to MSS SP-97 in the full material range — this is the same fitting as our weldo flange; see also nipoflanges and the flange dimensions charts.

How a Flangeolet Is Used

Hole cut in the run pipe: An opening is cut in the header (run) pipe where the branch is required.

Contoured base sits on the run: The flangeolet's saddle/contoured base is fitted over the opening to match the run-pipe curvature.

One weld attaches it: A single fillet/groove weld joins the fitting to the run pipe — no separate stub or reinforcing pad needed.

Flange face ready: The other end is a finished flange face (RF/RTJ) ready to bolt to the branch line's mating flange.

Integral reinforcement: The fitting's built-up body reinforces the opening and carries branch loads, satisfying the code's area-replacement requirement.

Flangeolet vs Weldolet + Separate Flange

Criterion	Flangeolet (one piece)	Weldolet + Welded Flange
Components	Single fitting	Olet + pipe stub + flange
Welds to make	One (to the run pipe)	Multiple (olet, stub, flange)
Reinforcement	Integral / self-reinforced (MSS SP-97)	Olet reinforced; extra welds
Fabrication	Faster, fewer joints	More time & inspection
Leak paths	Fewer welds = fewer leak points	More welds = more potential leaks

The flangeolet replaces an olet, a stub pipe, and a flange with one fitting and one weld — quicker, with fewer joints to inspect and fewer potential leak paths. It is identical to a weldo flange; a nipoflange is the variant built on a nipolet.

Flangeolet Specifications

Flangeolet are available in the following specifications:
Size	1/2"NB to 56"NB
Class	150#, 300#, 3000#, 6000#, 9000#
Sch (Schedule)	XS, XXS, STD & Schedule 20, 40, 80, 160
Pressure Ratings	PN 1 - PN 400
Stainless Steel Flangeolet	ASTM A 182 F - 304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L
Duplex Steel Flangeolet	ASTM A 182 - F 51, F 53, F 55
Alloy Steel Flangeolet	ASTM A 182 - F5, F9, F11, F21, F22 & F91
Carbon Steel Flangeolet	ASTM A 105
Low Temp. Carbon Steel Flangeolet (LTCS Flangeolet Flanges)	A 350 LF2
Copper Nickel (Cu-Ni) Flangeolet	C70600, 90/10, C71500, 70/30, C71640
Nickel Flangeolet	UNS N02200, UNS N02201
Monel Flangeolet	UNS N04400, UNS N05500, Alloy 20
Inconel Flangeolet	UNS N06600, UNS N06601, UNS N06625, UNS N08800, UNS N08810, UNS N08825
Hastelloy Flangeolet	UNS N10276, UNS N06022, UNS N10665, UNS N06455
Titanium Flangeolet	Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055
Other Services	Hot Dip Galvanized (GI) Flangeolet Sand Blasting on Flangeolet Shot Peening on Flangeolet Epoxy Coating on Flangeolet FBE Coating on Flangeolet

Flangeolet (Nipoflange) Dimensions — by Branch Size

Flangeolet / Nipoflange Dimension Diagram

Flangeolet / Nipoflange Dimensions Detail

Dimension note: flangeolet (nipoflange) dimensions are given by branch size below, per MSS SP-97 / ASME B16.5 facing. The contoured base is matched to the run-pipe OD — specify the run-pipe size and schedule, branch size, class, and facing for exact data.

Flangeolet (Nipoflange) Dimensions — Branch ½"

RATING	NOMINAL PIPE SIZE FROM 3/4" TO 36"
	Bore schedule	B	C	D	E	Weight [kg]
150#	STD	15,8	18,5	88,9	11,2	0,9
	XS	13,8	17,6			0,9
	160	11,7	11,7			0,9
	XXS	6,4	6,4			0,9
300#	Bore schedule	B	C	D	E	Weight [kg]
	STD	15,8	18,5	95,3	14,3	1,2
	XS	13,8	17,6			1,2
	160	11,7	11,7			1,2
	XXS	6,4	6,4			1,2
600#	Bore schedule	B	C	D	E	Weight [kg]
	STD	15,8	18,5	95,3	14,3	1,3
	XS	13,8	17,6			1,3
	160	11,7	11,7			1,3
	XXS	6,4	6,4			1,3
900#	Bore schedule	B	C	D	E	Weight [kg]
	STD	15,8	18,5	120,6	22,4	2,4
	XS	13,8	17,6			2,4
	160	11,7	11,7			2,4
	XXS	6,4	6,4			2,4
1500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	15,8	18,5	120,6	22,4	2,4
	XS	13,8	17,6			2,4
	160	11,7	11,7			2,4
	XXS	6,4	6,4			2,4
2500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	15,8	18,5	133,4	30,2	3,6
	XS	13,8	17,6			3,6
	160	11,7	11,7			3,6
	XXS	6,4	6,4			3,6

Flangeolet (Nipoflange) Dimensions — Branch ¾"

RATING	NOMINAL PIPE SIZE FROM 3/4" TO 36"
	Bore schedule	B	C	D	E	Weight [kg]
150#	STD	21	23,8	98,6	12,7	1,2
	XS	18,9	22,8			1,2
	160	15,6	15,6			1,4
	XXS	11,1	11,1			1,5
900#	Bore schedule	B	C	D	E	Weight [kg]
	STD	21	23,8	117,4	15,8	1,7
	XS	18,9	22,8			1,9
	160	15,6	15,6			2
	XXS	11,1	11,1			2,1
900#	Bore schedule	B	C	D	E	Weight [kg]
	STD	21	23,8	117,4	15,8	2
	XS	18,9	22,8			2,1
	160	15,6	15,6			2,2
	XXS	11,1	11,1			2,2
900#	Bore schedule	B	C	D	E	Weight [kg]
	STD	21	23,8	130	25,4	3,1
	XS	18,9	22,8			3,2
	160	15,6	15,6			3,2
	XXS	11,1	11,1			3,3
1500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	21	23,8	130	25,4	3,1
	XS	18,9	22,8			3,2
	160	15,6	15,6			3,2
	XXS	11,1	11,1			3,3
2500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	21	23,8	139,7	31,8	4,4
	XS	18,9	22,8			4,5
	160	15,6	15,6			4,5
	XXS	11,1	11,1			4,6

Flangeolet (Nipoflange) Dimensions — Branch 1½"

RATING	NOMINAL PIPE SIZE FROM 3/4" TO 36"
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	88,9	11,2	0,9
XS	13,8	17,6			0,9
160	11,7	11,7			0,9
XXS	6,4	6,4			0,9
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	95,3	14,3	1,2
XS	13,8	17,6			1,2
160	11,7	11,7			1,2
XXS	6,4	6,4			1,2
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	95,3	14,3	1,3
XS	13,8	17,6			1,3
160	11,7	11,7			1,3
XXS	6,4	6,4			1,3
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	120,6	22,4	2,4
XS	13,8	17,6			2,4
160	11,7	11,7			2,4
XXS	6,4	6,4			2,4
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	120,6	22,4	2,4
XS	13,8	17,6			2,4
160	11,7	11,7			2,4
XXS	6,4	6,4			2,4
	Bore schedule	B	C	D	E	Weight [kg]
STD	15,8	18,5	133,4	30,2	3,6
XS	13,8	17,6			3,6
160	11,7	11,7			3,6
XXS	6,4	6,4			3,6

Flangeolet (Nipoflange) Dimensions — Branch 2"

RATING	NOMINAL PIPE SIZE FROM 3" TO 36"
150#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	152,4	19,1	4,1
	XS	49,2	54,8			4,8
	160	42,8	42,8			5,1
	XXS	38,2	38,2			5,5
300#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	165,1		5,5
	XS	49,2	54,8		22,4	5,8
	160	42,8	42,8			6,1
	XXS	38,2	38,2			6,5
600#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	165,1	25,4	6,2
	XS	49,2	54,8			6,5
	160	42,8	42,8			7
	XXS	38,2	38,2			7,2
900#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	215,9	38,1	13
	XS	49,2	54,8			13,3
	160	42,8	42,8			13,6
	XXS	38,2	38,2			13,9
1500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	215,9	38,1	13
	XS	49,2	54,8			13,3
	160	42,8	42,8			13,6
	XXS	38,2	38,2			13,9
2500#	Bore schedule	B	C	D	E	Weight [kg]
	STD	52,5	56,4	235	50,8	18,4
	XS	49,2	54,8			18,6
	160	42,8	42,8			19
	XXS	38,2	38,2			19,3

Flangeolet (Nipoflange) Dimensions — Branch 4"

RATING	NOMINAL PIPE SIZE FROM 5" TO 36"
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	130	229	23,9	11,5
	XS-80	130			11,5
	160-XXS	160			13
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	140	254	31,8	16
	XS-80	140			16
	160-XXS	170			17
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	160	273	44,5	24
	XS-80	160			24
	160-XXS	195			26
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	170	292	50,8	28
	XS-80	170			28
	160-XXS	205			29,5
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	180	311	60,2	38
	XS-80	180			38
	160-XXS	215			40
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	250	356	82,4	70,5
	XS-80	250			70,5
	160-XXS	281			72

Flangeolet (Nipoflange) Dimensions — Branch 6"

RATING	NOMINAL PIPE SIZE FROM 8" TO 36"
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	150	279	25,4	23,5
	XS-80	170			25
	160-XXS	195			27
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	160	318	36,6	36,6
	XS-80	175			37,5
	160-XXS	205			39
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	185	356	54,1	49,5
	XS-80	200			51
	160-XXS	230			53,2
900#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	210	381	62	62,5
	XS-80	225			64,3
	160-XXS	250			66
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	240	394	88,9	87,5
	XS-80	255			89
	160-XXS	285			91,2
150#	Bore schedule	Length	D	E	Weight [kg]
	10-STD	340	483	114,3	186
	XS-80	360			189
	160-XXS	385			192,5

Why Choose Tesco Flangeolets?

⚡ One Fitting, One Weld

Replaces an olet, stub, and flange with a single fitting and a single weld — faster fabrication and fewer joints to inspect.

🔨 Integrally Reinforced

The built-up body reinforces the branch opening and carries branch & bending loads without a separate reinforcing pad, per MSS SP-97.

🔒 Fewer Leak Paths

Fewer welds mean fewer potential leak points and less NDT, improving the integrity of branch and instrument connections.

📐 Standard Flange Face

A finished RF/RTJ flange face to ASME B16.5 bolts up directly to standard mating flanges and gaskets.

🧬 Full Material Range

A105, SS 304/316/321, Monel, Inconel, and Incoloy for gas, steam, and corrosive or high-temperature headers.

📝 Made to the Run Pipe

Contoured to your header OD and branch size, in the class and facing required, certified with EN 10204 3.1 MTC.

Material Selection Guide

Material	Properties	Typical Use
A105 Carbon Steel	Strong, economical	Non-corrosive gas, steam & liquid headers
SS 304 / 316 / 316L	Good corrosion resistance	Process, chemical & hygienic branches
SS 321	Stabilised for high temperature	High-temperature steam & gas lines
Monel 400	Excellent in HF & marine media	HF, seawater & reducing media
Inconel / Incoloy	High-temperature & corrosion resistance	High-temperature & corrosive branches

Installation Guide

Confirm run OD, branch & class: Verify the header (run) pipe OD/schedule, branch size, pressure class, facing, and material — the base is contoured to the run OD.

Mark & cut the opening: Mark the branch location and cut the opening in the run pipe to suit the fitting bore.

Fit the contoured base: Seat the flangeolet's saddle on the run pipe so it matches the curvature and aligns square to the branch direction.

Weld per WPS: Make the attachment weld to a qualified procedure; inspect (NDT/PWHT) as the code requires.

Bolt the branch & test: Bolt the branch line's flange to the flangeolet face with the correct gasket and bolting, then pressure-test.

⚠ Match the contour to the run pipe & weld to procedure: A flangeolet's base is contoured for a specific run-pipe OD — using it on the wrong header size gives a poor fit and weld. Confirm the run OD, branch size, class, and facing when ordering, weld to a qualified WPS with the required NDT/PWHT, and use the correct gasket and bolting for the facing and class so the integral reinforcement and joint perform as designed.

Industry Applications

Industry	Typical Use	Why Flangeolet
Oil & Gas	Flanged branches off headers & manifolds	One-weld branch; self-reinforced
Refinery & Petrochemical	Branch & instrument connections	Fewer welds; full material range
Power Generation	Steam-header branches	SS 321 high-temperature service
Chemical Plants	Corrosive-header branches	Monel / Inconel / Incoloy
Pipelines	Take-off & vent/drain branches	High-class reinforced outlets
Fertilizer & Process	Header branch connections	Fast, code-compliant branches
Shipbuilding & Offshore	Topside & utility headers	SS / alloy corrosion resistance
Water & Utilities	Branch & instrument tappings	Economical one-piece branch

Frequently Asked Questions

Q1. What is a flangeolet?

A flangeolet is a self-reinforced branch outlet fitting that combines an olet (branch connection) and a flange in one forging. It welds onto a run pipe like a weldolet and presents a finished flange face for the branch, so a flanged branch connection is made with one fitting and one weld. It is made to MSS SP-97.

Q2. Is a flangeolet the same as a weldoflange or nipoflange?

“Flangeolet,” “weldoflange,” and “nipoflange” all describe a one-piece branch outlet that integrates an olet-type reinforced connection with a flange face. Flangeolet/weldoflange is built on a weldolet-style base; a nipoflange is the variant built on a nipolet. The function — a flanged branch in one self-reinforced fitting — is the same.

Q3. How is a flangeolet better than a weldolet plus a separate flange?

It replaces an olet, a stub pipe, and a separate welded flange with a single fitting and a single weld. That means faster fabrication, fewer welds and inspections, fewer potential leak paths, and integral reinforcement of the branch opening — all in one component.

Q4. What standard covers flangeolets?

Flangeolets are made to MSS SP-97, the standard for forged integrally-reinforced branch outlet fittings (which also covers weldolets, sockolets, threadolets, etc.), with the flange face to ASME B16.5. This gives the self-reinforced design that meets the branch area-replacement rule without a separate pad.

Q5. Does a flangeolet need a reinforcing pad?

No. A flangeolet is self-reinforced — its built-up body provides the area replacement needed at the branch opening, so a separate reinforcing pad is not required (subject to the branch design check per the applicable code).

Q6. What classes, facings, and materials are available?

Class 150 to 2500 and PN6 to PN400, with RF, RTJ, or FF facings to ASME B16.5, in A105 carbon steel, SS 304/316/321, Monel, Inconel, and Incoloy. The class, facing, and material are chosen for the header service and the mating branch flange.

Q7. Why must the contour match the run pipe size?

The base of a flangeolet is contoured (saddle-shaped) to fit a specific run-pipe outside diameter. If used on a different header size it will not seat properly and the weld will be poor. So the run-pipe OD and schedule must be specified along with the branch size when ordering.

Q8. Can flangeolets be supplied to our drawing and certified?

Yes. We supply flangeolets to MSS SP-97 / ASME B16.5, or to your drawing — run OD, branch size, class, facing, and material — with EN 10204 3.1 material test certificates on request. Send your header and branch details for a recommendation and quote.

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