Forged Union Manufacturer, Supplier & Exporter
A forged union is a three-piece fitting — a male end, a female end and a union nut — that joins two small-bore pipes and can be taken apart without turning either pipe. Raaj Fittings manufactures and exports forged unions with socket weld and threaded ends to MSS SP-83, in stainless steel, carbon steel, low-temperature carbon steel, alloy steel and other grades.
Unions are installed wherever a small-bore line must be opened regularly: next to valves, pumps, traps, meters and instruments that need maintenance or replacement. Unscrewing the nut separates the two ends, so the component can be removed without cutting pipe or dismantling a long run.
All unions are supplied with EN 10204 3.1 mill test certificates, with 3.2 certification and third-party inspection on request.
We export forged unions to EPC contractors, plant operators and stockists across the Middle East and GCC, Europe and the Americas — with NPT threads for US and Gulf projects or BSP threads where European and Middle Eastern specifications call for them.
Union Specifications
⅛" NPS to 3" NPS
Class 3000 and Class 6000
MSS SP-83; materials and threads as ASME B16.11 fittings
Socket weld (SW) or female threaded (NPT / BSPT / BSPP), or mixed ends
Metal-to-metal ground seat (spherical to conical) as standard
Male end, female end and nut, each forged and CNC machined
EN 10204 3.1 mill test certificate as standard; EN 10204 3.2 on request
Materials & Grades
We supply forged unions in the following materials and grades. All grades are supplied with EN 10204 3.1 / 3.2 Mill Test Certificates.
Stainless Steel Forged Unions
Stainless steel forged fittings deliver excellent corrosion resistance in chemical, pharmaceutical, food processing, and marine environments. All grades supplied to ASTM A182 specification.
(ASTM A182 F304 / F304L) General corrosion resistance; food processing, dairy, and chemical service
(ASTM A182 F316 / F316L) Superior chloride and acid resistance; pharmaceutical, offshore, and chemical processing
(ASTM A182 F316H) Elevated-temperature creep strength for high-temperature process service
(ASTM A182 F317 / F317L) Higher molybdenum content; superior corrosion resistance in concentrated acid service
(ASTM A182 F321) Titanium-stabilised; resists sensitisation at sustained elevated temperatures
(ASTM A182 F347) Columbium-stabilised; used in heat exchangers and high-temperature piping
Duplex & Super Duplex Stainless Steel Forged Unions
Delivering approximately twice the yield strength of austenitic stainless steel with excellent resistance to stress corrosion cracking, pitting, and erosion — ideal for offshore, subsea, and chemical processing environments.
(UNS S31803 / S32205, ASTM A182 F51) Offshore topsides, chemical plant, and seawater cooling systems
(UNS S32750, ASTM A182 F53) Subsea equipment, desalination, and high-chloride offshore service
(UNS S32760, ASTM A182 F55) High-temperature, high-chloride offshore and subsea service applications
Nickel Alloy Forged Unions
For the most severe corrosive, high-temperature, and sour service environments where standard stainless steel grades are insufficient.
(UNS N06600) High-temperature oxidation and carburisation resistance
(UNS N06625) Outstanding corrosion resistance; offshore, chemical, and subsea service
(UNS N08825) Resistance to phosphoric and sulfuric acids; FGD and chemical plant
(UNS N10276) Universal corrosion resistance across the widest range of aggressive media
(UNS N06022) Superior resistance to oxidising and reducing acids and pitting attack
(UNS N04400) Seawater, hydrofluoric acid, and marine and alkali service
(UNS N08020) Engineered for sulfuric acid and aggressive chemical process service
Exceptional corrosion resistance in seawater and oxidising media at low density
Carbon Steel Forged Unions
Carbon steel is the standard material for forged fittings in general-purpose, hydrocarbon, steam, and elevated-temperature service. The primary grade for forged carbon steel fittings is ASTM A105.
Primary grade for forged carbon steel fittings and flanges — covers ambient and elevated-temperature service in pressurised piping systems.
Low-temperature carbon steel, impact-tested for service down to -46°C (-50°F) — LNG, cold climate, and cryogenic piping applications.
Low-temperature carbon steel, impact-tested to -101°C (-150°F) — for the most demanding cold-temperature service applications.
Alloy Steel Forged Unions
Chromium-molybdenum alloy steel grades for high-temperature, high-pressure service in power generation, petrochemical, and refinery applications. All grades supplied to ASTM A182 specification.
(5% Cr · ½% Mo) Refinery hydroprocessing and high-temperature service
(9% Cr · 1% Mo) High-temperature steam and hydrogen-rich process service
(1¼% Cr · ½% Mo) Thermal power plant steam, feedwater, and reheat piping
(2¼% Cr · 1% Mo) Reactors and high-temperature pressure piping in petrochemical plants
(9% Cr · 1% Mo · V · Nb) Ultra-supercritical power plant main steam and hot reheat piping
How a Union Works
Each pipe is welded or screwed into its own end piece. The nut is captive on the female end and screws onto a thread on the male end. As the nut is tightened, it draws the two ends together until their ground seats meet; the metal-to-metal contact forms the seal without a gasket. Loosening the nut lets the ends separate cleanly.
- Removable joint — disconnect without rotating the pipe.
- Ground metal seat — no gasket to replace; the seat re-seals after dismantling.
- Socket weld or threaded — welded ends for process service, threaded for utilities.
- Compact — much smaller than a pair of flanges on small-bore lines.
Union or Coupling?
A full coupling joins two pipes permanently. A union joins them in a way that can be undone, which is why it is placed next to equipment that must come out for service. In threaded systems, unions are often combined with pipe nipples and street elbows to make up compact, serviceable assemblies.
Choosing Class and Seat
Class 3000 unions suit most process and utility service; Class 6000 unions are used for higher pressures. The standard ground seat is metal-to-metal; unions with alternative seating can be quoted to order. As unions involve threads and seating surfaces, check that they are permitted by your piping specification for the fluid concerned, as some specifications limit them in hazardous service.
Applications & Industries
- Connections at valves, steam traps, strainers and meters
- Pump and small equipment connections in process plants
- Instrument and analyser hook-ups
- Hydraulic and lube oil systems
- Compressed air, water and steam utility lines
When ordering, give the size, class, end type and thread form for each end, and the material grade — for example 1" Class 3000 socket weld union, ASTM A105N. Unions with one socket weld end and one threaded end can be supplied for transitions at equipment.
See the complete range of forged fittings.
Testing, Inspection, Marking & Packing
Forged unions are produced under our quality assurance process:
- Incoming material verification with PMI testing
- Chemical and mechanical testing to the applicable ASTM specification
- Heat treatment as required, with pickling and passivation for stainless steels
- Dimensional inspection of sockets, threads, nut and seat, with thread gauging
- Seat contact check on assembled unions
- Marking with manufacturer’s mark, grade, size, class and heat number
Supplied with EN 10204 3.1 mill test certificates; EN 10204 3.2 certificates and third-party inspection are available on request.
Fittings are packed for export with plastic caps protecting threads and sockets, rust-preventive or VCI wrapping on carbon and alloy steel, and seaworthy wooden cases; marking, tagging and packing to your specification are available on request.
Why Choose Raaj Fittings for Forged Unions?
Raaj Sagar Steels has supplied piping components since 2003 and today manufactures forged fittings at two plants in India for buyers in the Middle East, Europe and the Americas.
- Manufactured in-house — Forged unions are made in our own plants, so material, dimensions and delivery stay under our control.
- Ready stock, short lead times — common sizes and grades are held in stock for prompt dispatch; other sizes, grades and specials are manufactured to order.
- Certified quality — ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified; PED 2014/68/EU and IBR supply available, and NACE MR0175 / ISO 15156 material on request.
- 100% material verification — PMI testing on incoming material and EN 10204 3.1 mill test certificates with every order; 3.2 certificates on request.
- Third-party inspection ready — we regularly work with SGS, Bureau Veritas, TÜV and DNV.
- Export documentation — MTCs, certificates of origin, packing lists and inspection reports to suit projects in the GCC, Europe and the Americas.
- Export packing — seaworthy packing with end and face protection, and packing to your specification on request.
- Fast response — our team replies to enquiries within one business day.
Forged Unions — FAQs
A pipe union is a three-piece fitting — male end, female end and nut — that joins two pipes and can be disconnected without rotating either pipe.
Forged steel socket weld and threaded unions are covered by MSS SP-83, in Class 3000 and Class 6000.
The two ends have ground seats that meet metal to metal when the nut is tightened, forming a seal without a gasket.
Next to valves, traps, meters, pumps and instruments that need to be removed for maintenance, so they can be taken out without cutting pipe.
A coupling joins two pipes permanently. A union can be undone with a spanner to separate the pipes.
Yes. We supply forged unions for projects under the European Pressure Equipment Directive (PED 2014/68/EU), and with IBR certification for Indian boiler applications. NACE MR0175 / ISO 15156 compliant material is also available on request for sour service in the Middle East and the Americas.
