Concentric and eccentric types
Product formButt Weld Fittings
/ 01 — TECHNICAL OVERVIEW
Reducers
Butt weld fittings create permanent welded transitions for changes in direction, branch connections, pipe-size reduction and line closure. Correct selection requires the fitting type, material grade, manufacturing class, dimensional standard, nominal size, wall or schedule, end preparation and inspection scope to be defined together.
NESCO Pipe & Tubes supplies elbows, tees, reducers, stub ends and end caps for process piping, pressure systems, fabrication packages and maintenance requirements. Each fitting requirement is reviewed against the connecting pipe, service conditions, approved piping class and welding procedure.
The NESCO range includes stainless steel, duplex, super duplex, nickel-alloy, titanium and copper-nickel fittings, subject to the applicable grade, product standard, size, wall and manufacturing route.
Seamless, welded or qualified fabricated construction can be coordinated where permitted by the governing specification. Heat-wise traceability, Mill Test Certificates, dimensional inspection, NDT coordination and export-ready packing are available as specified.
How it is made
01
Suitable feedstock is selected according to the fitting specification, size, wall and manufacturing route.
02
Progressive pressing, rolling or forming creates the required diameter transition without abrupt flow changes.
03
Heat treatment is completed to the material specification and manufacturing class.
04
Large and small ends are calibrated, trimmed and bevelled to the connecting walls.
05
End diameters, length, wall, eccentric orientation and required NDT are verified.
Request reviewed quotation Material documents on request
/ 02 — PRODUCT DETAIL
Built around the specification.
Butt weld fittings create permanent welded transitions for changes in direction, branch connections, pipe-size reduction and line closure. Correct selection requires the fitting type, material grade, manufacturing class, dimensional standard, nominal size, wall or schedule, end preparation and inspection scope to be defined together.
Key features01 02 03 04
Smooth diameter transition
Schedule and end thickness matched to piping system
Flat-side orientation defined for eccentric reducers
Common specification references
STD
ASME B16.9
STD
Material specification compatible with piping class
STD
Dimensional and wall-thickness checks
/ 03 — AVAILABLE GRADES
Available Material Grades
NESCO supplies the material families shown below in butt weld fitting form, subject to fitting type, grade, class, size, wall, manufacturing route and availability.
Material familyCommon gradesTypical selection context
Austenitic stainless steelASTM A403 WP304/WP304L, WP316/WP316L, WP321 and WP347
General corrosion-resistant process and pressure piping
Duplex / super duplex stainless steelASTM A815 WP grades, including applicable duplex/super duplex grades based on UNS S31803/S32205 and S32750/S32760, with class/subclass as specified
Higher-strength chloride-bearing, seawater, offshore and severe-service piping
Nickel alloysASTM B366 grades including UNS N04400, N06600, N06625, N08825 and N10276
Severe corrosion and elevated-temperature piping
TitaniumASTM B363 Grades 2, 5 and 7 where applicable
Marine, heat-exchanger and selected chemical systems
Copper-nickelUNS C70600 (90/10 Cu-Ni) and UNS C71500 (70/30 Cu-Ni) under the applicable fitting or project specification
Marine, condenser and seawater piping
/ 04 — SUPPLY & CUSTOMISATION
Define the supply condition.
Final availability depends on the complete combination of material, dimensions, standard, condition, testing and quantity.
ParameterTypical information to specify
01Construction
Seamless, welded or fabricated construction, as permitted by the applicable product specification and project requirements
02Dimensions
NPS, schedule and standard
03End preparation
Bevelled to specified weld preparation
04Heat treatment
Solution annealed or as required by material standard
05Surface
Pickled/passivated, blasted, polished or mill finish
06Testing
PMI, dye penetrant, radiography/UT, dimensions and other specified tests
07Documentation
MTC, NDT reports, heat-treatment charts and inspection release
/ 05 — DIMENSIONS & SIZE RANGE
Dimensions aligned to the manufacturing route.
Butt-weld fitting dimensions must be coordinated with both connected pipe ends. State every run, branch or reducer end size and wall.
ParameterTypical definitionRFQ inputInspection focus
ConfigurationElbow angle, tee type, reducer type or closureExact type / drawingGeometry and orientation
End sizeNPS / OD at each connectionRun, branch, large and small endsFit with connecting pipe
WallSchedule or nominal/minimum wallEach end wall requirementForming thinning and weld preparation
End preparationStandard bevel or special weld detailAngle, land and root detailField fit-up
/ 06 — FITTING & PIPE REFERENCES
Fitting and pipe references, clearly separated.
Fitting material and dimensional requirements are stated separately from the pipe-dimensional references used to coordinate compatible weld ends.
ReferenceWhat it coversRole
ASME B16.9Overall dimensions, tolerances, ratings, testing and marking for factory-made wrought butt-welding fittings
Dimensions / ratings
ASME B16.25Preparation of butt-welding ends for joining into piping systems
Weld ends
MSS SP-43Wrought and fabricated butt-welding fittings for low-pressure, corrosion-resistant applications, including applicable light-wall fittings
Low-pressure / light-wall fitting reference
ASTM A403/A403MWrought austenitic stainless steel piping fittings
Stainless material / class
ASTM A815/A815MWrought ferritic, ferritic/austenitic and martensitic stainless steel piping fittings
Duplex material / class
ASTM B366/B366MFactory-made wrought nickel and nickel-alloy fittings
Nickel-alloy material
ASTM B363Seamless and welded unalloyed titanium and titanium-alloy welding fittings
Titanium material
ASME B36.19MStainless steel pipe dimensions and schedules, where applicable
Pipe dimensional compatibility
ASME B36.10MWelded and seamless wrought steel pipe dimensions and schedules, where applicable
Pipe dimensional compatibility
Project specification / drawingSpecial geometry, wall transitions, tangents, barred branches and supplementary examination
Order-specific
/ FITTING SELECTION GUIDE
Match the fitting to the change in flow path.
Start with the required direction, branch, transition or closure, then coordinate every end with the connected pipe. The approved piping class and design specification govern final selection.
Fitting typeTypical use
ElbowsChange line direction using the specified angle and long- or short-radius pattern
TeesCreate equal or reducing 90-degree branch connections
ReducersConnect different pipe sizes using concentric or eccentric transitions
Stub EndsPair with lap-joint backing flanges for rotatable, demountable connections
End CapsProvide permanent welded closure at a pipe end
/ 07 — INSPECTION & TESTING
Evidence before dispatch.
01MTC, heat number and fitting class verification
02NPS, schedule, centre-to-end and end-diameter checks
03Wall-thickness distribution after forming
04Bevel angle, land and squareness inspection
05PMI and liquid-penetrant examination when specified
06Radiographic or ultrasonic examination of welds by class or purchase order
07Heat-treatment and NDT report review
08Marking, bevel protection and packing verification before dispatch
PACKAGING & MARKING
Protected and traceable.
01Ends capped to protect bevels and internal cleanliness
02Fittings nested or individually wrapped without metal-to-metal damage
03Small items boxed; heavy fittings palletised or crated
04Heat-wise tags and durable product marking
05Export packing and lifting points planned for large fittings
/ 08 — APPLICATIONS & INDUSTRIES
Engineered for demanding service environments.
From process plants to marine systems, NESCO coordinates material, dimensions and documentation around the operating conditions of each application.
01
Process piping02
Oil and gas facilities03
Chemical and fertiliser plants04
Power generation05
Desalination and water treatment06
Marine piping07
Food and pharmaceutical utilities08
Fabrication and maintenanceIndustries servedOne supply partner across critical sectors.
Process pipingOil & gasRefineriesChemical & fertiliserPower generationMarine & offshoreWater treatmentFood & pharmaceutical
/ 09 — WHY NESCO PIPE & TUBES
Built for buyers who cannot leave details to chance.
From specification review to export documentation, NESCO coordinates the technical and commercial details as one complete supply requirement.
01
Specification control
NESCO reviews the grade, product standard, dimensions, condition and acceptance criteria as one coordinated requirement.
02
Multi-material sourcing
Stainless steel, duplex, nickel alloy, copper-nickel and titanium fitting requirements can be combined within one project enquiry.
03
Traceable documentation
Heat numbers, MTCs and agreed inspection records are aligned with the purchase order before dispatch.
04
Inspection coordination
PMI, dimensional checks, NDT and third-party witnessing can be arranged against an approved inspection plan.
05
Value-added processing
Machining, end preparation, special dimensions, surface finishing or protective treatment can be reviewed against the applicable fitting specification and project requirements.
06
Export-ready packing
Identification, surface protection and packing are planned around product geometry and the final transport route.
07
Responsive RFQ review
Technical and commercial inputs are consolidated early so queries are resolved before quotation and production.
08
One accountable supply desk
NESCO provides a single contact for material, processing, documentation, packing and delivery coordination.
/ 10 — FREQUENTLY ASKED QUESTIONS
Clear answers before you specify.
Quick guidance on product selection, standards, dimensions, inspection and documentation. For project-specific requirements, NESCO will review the complete enquiry with your team.
01When should an eccentric reducer be used?
Eccentric reducers are used when maintaining a flat side helps manage drainage, vapour pockets or equipment-nozzle alignment; orientation must be stated.
02How should reducer wall be specified?
State both end sizes, schedule or wall at each end, construction class, length and concentric/eccentric configuration.
03What information is required to quote a butt-weld fitting?
Provide fitting type, angle or configuration, material grade, material class, dimensional standard, NPS, schedule or wall, quantity and NDT.
04Must the fitting schedule match the pipe?
The weld-end outside diameter and wall should be compatible with the connecting pipe and approved welding procedure.
05What do WP-S, WP-W, WP-WX or WP-WU indicate?
These class markings identify manufacture and examination routes under the applicable fitting specification; specify the class required by the piping design.
06Can special dimensions be supplied?
Drawing-specific radii, tangents, end walls or fabricated configurations can be reviewed with design and inspection requirements.
/ 11 — REQUEST FOR QUOTATION Nesco direct sales desk
Ready to source?Start with the details you already have.
Our team will review the grade, dimensions, testing and delivery requirements together.