What standards apply to Nipoflanges?

Nipoflanges are governed by MSS SP-97 (Integrally Reinforced Forged Branch Outlet Fittings). Flange face dimensions conform to ASME B16.5 (up to 24″) or ASME B16.47 (above 24″). Pressure-temperature ratings follow ASME B16.5 class designations: 150#, 300#, 600#, 900#, 1500#, and 2500#. Material standards: ASTM A105 (carbon steel), ASTM A182 (alloy and stainless forgings), ASTM A350 LF2 (LTCS).

What sizes are Nipoflanges available in?

Tesco Steel manufactures Nipoflanges with header run sizes from ¾″ to 36″ NB and branch sizes from ½″ to 6″ NB. Schedule options: STD, XS, 40, 80, 160, and XXS. Pressure classes: 150#, 300#, 600#, 900#, 1500#, and 2500# per ASME B16.5.

What pressure classes do Nipoflanges come in?

Nipoflanges are manufactured in six ASME B16.5 pressure classes: 150# (PN 20), 300# (PN 50), 600# (PN 110), 900# (PN 150), 1500# (PN 260), and 2500# (PN 420). Classes 900# and above are most common in oil and gas, high-pressure steam, and subsea applications.

How is a Nipoflange installed on a pipeline?

Installation: (1) Cut a circular hole in the header pipe matching the branch bore. (2) Saddle-weld the Nipoflange run side to the header outer surface using a full-penetration fillet or groove weld per MSS SP-97, providing integral reinforcement. (3) Connect the branch pipe to the flange face using standard bolting and gasket. This eliminates the need for a tee fitting and gives a fully flanged, demountable branch connection.

Nipoflanges (Nipo Flanges) Manufacturer in India

Q: What is a Nipoflange?

A Nipoflange is a one-piece forged branch connection combining a Nipolet on the run (header) side with a weld-neck flange on the branch side. The run side is saddle-welded directly into the header pipe, eliminating the need for a separate tee fitting. The branch side presents a standard ASME B16.5 raised-face weld-neck flange for a flanged, demountable branch connection.

Q: What is the difference between a Nipoflange and a Weldoflange?

Both are one-piece branch-outlet-plus-flange fittings per MSS SP-97. A Nipoflange uses a Nipolet-style run connection, typically for branch sizes ½″–6″ NB. A Weldoflange uses a larger Weldolet saddle connection for branch sizes 2″–16″ NB. Nipoflanges suit smaller high-pressure branches; Weldoflanges suit larger branch diameters.

Q: What materials are Nipoflanges available in?

Nipoflanges are available in: Carbon Steel (ASTM A105), Stainless Steel (ASTM A182 F304, F304L, F316, F316L, F321, F347, F904L), Alloy Steel (F5, F9, F11, F22, F91), Duplex and Super Duplex (F51, F53, F55), LTCS (A350 LF2), Inconel 625/825, Hastelloy C276, Monel 400/K500, Cupro Nickel (C70600, C71500), and Titanium (Gr.2, Gr.5).

Q: Where are Nipoflanges used?

Nipoflanges are used where a compact, high-integrity flanged branch is needed on a main pipeline. Applications include: bypass and sampling lines on oil and gas pipelines, pressure relief connections on petrochemical reactors, instrument take-off points on high-pressure steam lines, vent and drain connections on offshore piping, and chemical injection quills on process lines.

Nipoflange manufacturer India - ASTM A105 Nipo Flange

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A Nipoflange (also written Nipo Flange or Nipoflanges) is a one-piece integrally reinforced forged fitting that combines a Nipolet branch outlet on the run side with a weld-neck flange on the branch side. The run side is saddle-welded directly onto the header (run) pipe — just like a standard Nipolet — providing integral weld reinforcement per MSS SP-97. The branch side presents a standard ASME B16.5 weld-neck flange face, giving a fully flanged, demountable branch connection without requiring a separate tee fitting.

Tesco Steel & Engineering manufactures Nipoflanges in India across a comprehensive range of materials, sizes, and pressure classes. Our Nipoflanges are 100% hydrostatically tested and supplied with material test certificates (MTCs) in accordance with EN 10204 3.1 / 3.2.

What is a Nipoflange?

A Nipoflange is defined under MSS SP-97 as an integrally reinforced forged branch outlet fitting. It is the industry solution when engineers need a branch connection that is:

Compact — no separate tee, no additional spool piece
Flanged — branch terminates in a weld-neck flange for easy disassembly
Reinforced — integral pad reinforcement per ASME B31.3 / B31.1 branch reinforcement rules
High pressure — rated up to 2500# (PN 420)

Nipoflange vs Weldoflange — Key Differences

Feature	Nipoflange	Weldoflange
Governing Standard	MSS SP-97	MSS SP-97
Run Side Geometry	Nipolet-style (smaller saddle)	Weldolet-style (larger saddle)
Typical Branch Size	½″ – 6″ NB	2″ – 16″ NB
Header Size Range	¾″ – 36″ NB	4″ – 36″ NB
Best Use Case	Small high-pressure branches (sampling, instruments, bypass)	Larger branch connections (sub-headers, tie-ins)
Reinforcement	Integral (nipolet pad)	Integral (weldolet contour)
Branch Side	ASME B16.5 weld-neck flange	ASME B16.5 weld-neck flange

Nipoflange Materials

Nipoflanges are available in all major piping material groups. Material selection is based on operating temperature, process fluid corrosivity, and design code requirements:

Material Group	Grade / Specification	Key Properties
Carbon Steel	ASTM A105	General purpose, −29°C to +427°C, most economical
LTCS (Low Temp Carbon Steel)	ASTM A350 LF2 Cl.1 / Cl.2	Charpy impact tested to −46°C, cryogenic service
Stainless Steel — Austenitic	ASTM A182 F304, F304L, F316, F316L, F321, F347, F904L	Corrosion resistant, food & chemical service
Alloy Steel (Cr-Mo)	ASTM A182 F5, F9, F11, F22, F91	High temperature creep resistance, power generation
Duplex Stainless Steel	ASTM A182 F51 (UNS S31803)	High strength + pitting resistance, offshore
Super Duplex	ASTM A182 F53 (S32750), F55 (S32760)	Seawater, sour gas, chloride environments
Nickel 200 / 201	UNS N02200 / N02201	Caustic soda, food processing
Monel 400 / K500	UNS N04400 / N05500	Seawater, HF acid, marine
Inconel 625 / 825	UNS N06625 / N08825	High temp oxidation, sour gas, nuclear
Hastelloy C276 / C22	UNS N10276 / N06022	Wet chlorine, FGD, mixed acids
Cupro Nickel	C70600 (90/10), C71500 (70/30)	Seawater piping, marine heat exchangers
Titanium	Gr. 2 (R50400), Gr. 5 (R56400)	Chemical processing, bleaching, desalination

Applicable Standards

Standard	Scope
MSS SP-97	Design and dimensions of integrally reinforced forged branch outlet fittings (Nipoflange, Weldoflange, Elboflange)
ASME B16.5	Flange face dimensions, bolt-hole patterns, pressure-temperature ratings (Class 150–2500, sizes up to 24″)
ASME B16.47	Large diameter flanges above 24″ NB (Series A: MSS SP-44; Series B: API 605)
ASME B31.3	Process piping branch reinforcement calculations
ASME B31.1	Power piping branch reinforcement calculations
ASTM A105	Carbon steel forging material specification
ASTM A182	Alloy and stainless steel forging material specification
EN 1092-1	European flanges (metric PN rating system)

Nipoflange Applications by Industry

Industry	Typical Nipoflange Applications	Common Material
Oil & Gas — Upstream	Wellhead bypass lines, sampling connections, chemical injection quills	A105, A350 LF2, F316L
Refinery / Downstream	Pressure relief line take-offs, hydrocarbon process branches, instrument connections	A105, F11, F22, F316
Offshore / Subsea	Topside vent and drain branches, umbilical take-off points, seawater service lines	F51, F53, C70600, Titanium
Petrochemical	Reactor vessel branches, high-pressure loop connections, secondary line tie-ins	F316L, F321, F347, Hastelloy
Power Generation	Steam main branch connections, condenser feed lines, attemperator connections	F22, F91, A105
Chemical Processing	Acid service branch lines, corrosive fluid sampling, vent connections	F316L, Hastelloy C276, Titanium Gr.2
Water Treatment / Desalination	Dosing and injection lines, pressure monitoring branches	F316L, Duplex F51, C70600
LNG / Cryogenic	Low temperature branch connections on LNG pipelines	A350 LF2, F304L

Why Choose Nipoflanges?

Fewer Leak Paths

Replaces tee + two flanges + two welds with a single forged unit. Every eliminated joint is a potential leak point removed from the system.

Compact Footprint

Eliminates a separate tee fitting and spool pieces. Ideal for congested pipe racks, platforms, and modules where space is critical.

Integral Reinforcement

The forged nipolet pad provides branch reinforcement per ASME B31.3 / B31.1 — no separate reinforcing pad welding required.

Flanged Demountability

The weld-neck flange branch side allows the branch piping to be fully removed for maintenance, inspection, or replacement without cutting the header.

High Pressure Rated

Available through ASME B16.5 Class 2500# (PN 420). Suitable for the highest-pressure applications in subsea, wellhead, and high-pressure steam systems.

Lower Installed Cost

Fewer components means fewer procurement items, fewer inspection certificates, and fewer man-hours in the field — reducing total installed cost significantly.

Price Enquiry: Nipoflange prices vary by material, size, pressure class, and quantity. Click here to request an updated price list with ready-stock information. Tesco Steel maintains stock of standard A105 Nipoflanges and can export at competitive prices.

SPECIFICATIONS

Nipoflanges 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 Nipoflanges	ASTM A 182 F - 304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L
Duplex Steel Nipoflanges	ASTM A 182 - F 51, F 53, F 55
Alloy Steel Nipoflanges	ASTM A 182 - F5, F9, F11, F21, F22 & F91
Carbon Steel Nipoflanges	ASTM A 105
Low Temp. Carbon Steel Nipoflanges (LTCS Nipoflanges Flanges)	A 350 LF2
Cupro Nickel (Cu-Ni) Nipoflanges	C70600, 90/10, C71500, 70/30, C71640
Nickel Nipoflanges	UNS N02200, UNS N02201
Monel Nipoflanges	UNS N04400, UNS N05500, Alloy 20
Inconel Nipoflanges	UNS N06600, UNS N06601, UNS N06625, UNS N08800, UNS N08810, UNS N08825
Hastelloy Nipoflanges	UNS N10276, UNS N06022, UNS N10665, UNS N06455
Titanium Nipoflanges	Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055
Other Services	Hot Dip Galvanized (GI) Nipoflanges Sand Blasting on Nipoflanges Shot Peening on Nipoflanges Epoxy Coating on Nipoflanges FBE Coating on Nipoflanges

Nipo Flanges Dimensions

Nipo Flange 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

Nipo Flange 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

Nipo Flange 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

Nipo Flange 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

Nipo Flange 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

Nipo Flange 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

Frequently Asked Questions — Nipoflanges

What is a Nipoflange and how does it work?

A Nipoflange is a one-piece forged fitting combining a Nipolet branch outlet (run side) with a weld-neck flange (branch side), governed by MSS SP-97. The run side is saddle-welded onto the outer surface of the header pipe — just like a standard Nipolet — providing integral reinforcement without a separate pad. The weld-neck flange branch side then connects to the branch pipe via standard bolting and gasket, giving a fully flanged, demountable branch connection. This eliminates the separate tee fitting + two flanges + two spool welds that a conventional branch would require.

What is the difference between a Nipoflange and a Weldoflange?

Both are MSS SP-97 integrally reinforced branch outlet fittings with a weld-neck flange. The difference is the run-side geometry: a Nipoflange uses the smaller Nipolet-style saddle (typically branch sizes ½″–6″ NB), while a Weldoflange uses the larger Weldolet-style contour saddle (branch sizes 2″–16″ NB). Nipoflanges are chosen for small, high-pressure branches (sampling, instrument take-offs, pressure relief); Weldoflanges suit larger branch-to-header connections.

What standards govern Nipoflanges?

The primary design standard is MSS SP-97 (Integrally Reinforced Forged Branch Outlet Fittings). The flange face dimensions follow ASME B16.5 (up to 24″ NB) or ASME B16.47 (above 24″ NB). Pressure-temperature ratings are per ASME B16.5 classes: 150#, 300#, 600#, 900#, 1500#, 2500#. Materials conform to ASTM A105 (carbon steel), ASTM A182 (alloy/stainless forgings), or ASTM A350 LF2 (LTCS).

What materials are Nipoflanges available in?

Nipoflanges are available in: Carbon Steel (ASTM A105) · LTCS (A350 LF2) · Stainless Steel (A182 F304, F304L, F316, F316L, F321, F347, F904L) · Alloy Steel (F5, F9, F11, F22, F91) · Duplex (F51 / S31803) · Super Duplex (F53 / S32750, F55 / S32760) · Nickel 200/201 · Monel 400/K500 · Inconel 625/825 · Hastelloy C276/C22 · Cupro Nickel (C70600, C71500) · Titanium (Gr. 2, Gr. 5).

What sizes and pressure classes are Nipoflanges available in?

Branch sizes: ½″ to 6″ NB. Header (run) sizes: ¾″ to 36″ NB. Bore schedules: STD, XS, Sch 40, Sch 80, Sch 160, XXS. Pressure classes: 150# · 300# · 600# · 900# · 1500# · 2500# (equivalent PN 20 through PN 420). The exact weight and dimensions for each branch size, schedule, and pressure class are tabulated in the dimension tables on this page.

Where are Nipoflanges used?

Typical applications: oil & gas — bypass lines, sampling taps, pressure relief line take-offs on pipelines and wellheads; refineries — instrument connections, secondary process branch lines; power plants — steam main branch connections, attemperator lines; offshore — topside vent/drain branches, chemical injection quills; petrochemical — reactor vessel branches, high-pressure loop connections; LNG/cryogenic — sub-zero branch connections (LTCS or F304L Nipoflanges).

Does a Nipoflange require a separate reinforcing pad?

No. A key advantage of the Nipoflange is its integral reinforcement. The forged nipolet pad on the run side provides all required branch reinforcement per ASME B31.3 / B31.1 branch reinforcement calculations — no separate saddle pad welding is needed. This simplifies fabrication, reduces weld joints in the line, and speeds up piping installation.

How do I install a Nipoflange on a pipeline?

Installation steps: (1) Mark and cut a circular hole in the header pipe to the branch bore diameter. (2) Position the Nipoflange run side against the header outer surface; the run-side contour matches the header OD. (3) Weld the run side to the header using a full-penetration groove weld or fillet weld per MSS SP-97 and the applicable piping code (B31.3 / B31.1). (4) After weld examination and PWHT (if required), bolt the branch pipe's mating flange to the Nipoflange weld-neck flange using the appropriate gasket and stud-bolt set per ASME B16.5.

Global Export: Tesco Steel exports Nipoflanges to the UAE, Saudi Arabia, Qatar, Kuwait, Oman, Bahrain, USA, UK, Germany, Canada, Australia, Singapore, Malaysia, Nigeria, South Africa and 80+ countries worldwide.

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Quick Reference

Branch Size	½″ – 6″ NB
Header Size	¾″ – 36″ NB
Pressure Class	150# – 2500#
Standard	MSS SP-97
Flange Face	ASME B16.5
Common Material	ASTM A105
Face Types	RF, FF, RTJ
Test	Hydro 100%
Certs	EN 10204 3.1/3.2

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