Nipolet – One-Piece Branch Outlet with Integrated Nipple SS 304 316 Duplex Super Duplex

Product Overview

Nipolet — Integrated Branch Outlet & Nipple

The Nipolet is a one-piece forged fitting that combines the integrally reinforced branch outlet base of a Weldolet with an integral nipple body extending upward from the base. Where a conventional branch connection requires three separate components — a Weldolet, a short nipple and an end fitting such as a valve or instrument connection — the Nipolet provides the Weldolet base and the nipple in a single forged piece, eliminating two weld joints from the branch assembly.

The base of the Nipolet is contoured to match the outer diameter of the run pipe in the same manner as a Weldolet, and is fillet-welded to the run pipe at the drilled branch opening. The integral nipple body rises perpendicularly from the base. The top end of the nipple is available with a male NPT threaded end (for direct connection to a screwed valve, instrument or fitting), a plain butt-weld end (for welded branch continuation), or a socket weld end. Standard nipple extension lengths above the base weld are 3 inches and 6 inches; custom lengths are available to order.

Because the Nipolet is forged from a single billet, there is no weld between the reinforcement zone and the nipple body. This eliminates the heat-affected zone that would exist at the Weldolet-to-nipple joint in a conventional assembly, improving fatigue resistance at the branch nozzle in vibrating or thermally cycling pipelines.

MSS SP-97ASTM A182 Run 3/4" to 24" NPSBranch 1/4" to 4" NPS NPT • BW • SW End3" • 6" Nipple Lengths

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MSSStandardSP-97

1Piece ForgingBase + Nipple Integral

3/4–24"Run Pipe RangeNPS

3/6"Nipple LengthCustom on Request

3Material GradesSS / Duplex / S.Duplex

Technical Data

Nipolet — Standard Size Range & End Options

Specify run pipe NPS, branch NPS, schedule (for both run and branch), nipple end type, nipple length and material grade. The base contour is machined to match the specific run pipe OD ordered. All dimensions in accordance with MSS SP-97.

Branch NPS	Branch O.D. (mm)	Nipple End Options	Standard Nipple Length	Run Pipe NPS Range	Thread (NPT end)
1/4"	13.7	Male NPT / BW / SW	3" (76 mm) • 6" (152 mm)	3/4" to 24"	18 TPI
3/8"	17.1	Male NPT / BW / SW	3" (76 mm) • 6" (152 mm)	3/4" to 24"	18 TPI
1/2"	21.3	Male NPT / BW / SW	3" (76 mm) • 6" (152 mm)	3/4" to 24"	14 TPI
3/4"	26.7	Male NPT / BW / SW	3" (76 mm) • 6" (152 mm)	1" to 24"	14 TPI
1"	33.4	Male NPT / BW / SW	3" (76 mm) • 6" (152 mm)	1-1/2" to 24"	11.5 TPI
1-1/2"	48.3	Male NPT / BW	3" (76 mm) • 6" (152 mm)	2" to 24"	11.5 TPI
2"	60.3	Male NPT / BW	3" (76 mm) • 6" (152 mm)	3" to 24"	11.5 TPI
3"	88.9	Male NPT / BW	6" (152 mm)	4" to 24"	8 TPI
4"	114.3	BW only	6" (152 mm)	6" to 24"	—

Custom nipple extension lengths available on request. Run pipe schedule and branch schedule must both be specified when ordering. Bevel prep on BW ends to ASME B16.25. All NPT threaded ends 100% go/no-go gauge inspected.

Joint Reduction

Nipolet vs Conventional Branch Assembly

Nipolet Assembly

1 component: Nipolet (base + nipple integral)
1 weld: base-to-run pipe fillet weld only
No HAZ between reinforcement and nipple body
Superior fatigue resistance in vibrating or cycling lines

Conventional Assembly

3 components: Weldolet + nipple + end fitting
3 welds: base, nipple-to-Weldolet, nipple-to-fitting
HAZ at each weld — multiple potential fatigue initiation points
More inspection points; higher fabrication cost

Available Materials

Material Grades for Nipolets

Grade 01

Stainless Steel 304 / 316

Austenitic stainless steel Nipolets for drain, vent and instrument branch connections on chemical, pharmaceutical and process pipelines where eliminating weld joints in the branch nozzle assembly reduces inspection cost and potential leak paths in corrosive service.

ASTM A182 F304ASTM A182 F316MSS SP-97

Grade 02

Duplex Steel

Duplex alloy Nipolets for instrument and injection branch connections on offshore process and desalination piping. The single-piece forging eliminates weld joints in the branch nozzle assembly at locations where duplex weld quality is difficult to maintain in confined offshore fabrication environments.

ASTM A182 F51UNS S31803UNS S32205

Grade 03

Super Duplex Steel

Super duplex Nipolets with PREN greater than 40 for instrument and chemical injection branch connections on seawater service and offshore topsides piping, where the one-piece forging reduces the number of weld joints that require full non-destructive examination and PWHT in the super duplex branch assembly.

ASTM A182 F53UNS S32750UNS S32760

Applications

Where Nipolets Are Used

01

Instrument Tapping Points

Pressure gauge, transmitter and thermowell connections on process pipelines where the Nipolet eliminates the Weldolet-plus-nipple assembly, reducing the branch nozzle to a single forged piece with one base weld and a direct male NPT connection to the instrument valve.

02

Chemical Injection Nozzles

Chemical injection nozzle connections in offshore process piping where the absence of a weld joint between the reinforcement base and the nipple body removes a corrosion risk at a joint that would otherwise contact the injected chemical at the nozzle bore.

03

Drain & Vent Nozzles

Drain and vent connections on process piping in Stainless Steel or Duplex Steel where the standard nipple length positions the drain valve at the correct height above the pipe insulation and cladding without requiring a separately welded nipple above the branch outlet base.

04

Vibrating & Thermally Cycling Lines

Branch connections on compressor discharge piping, pump discharge headers and heat exchanger inlet/outlet pipework where thermal cycling or mechanical vibration makes every weld joint in the branch nozzle a potential fatigue initiation point that the one-piece Nipolet eliminates.

Branch Outlet Range

Forged Nipolet