Application description

Widely used to connect pipes or to attach branch lines in oil and gas, petrochemical, hydraulic, pneumatic, water supply, fire protection, and instrumentation systems. Also suitable for high-pressure gas distribution, steam lines, chemical plants, and general industrial piping. Couplings and unions enable easy assembly, disassembly, and maintenance without cutting or re-threading pipe.

Production description

Steel bar or seamless pipe is cut, forged (or machined from solid), then heat treated. Threads are cut or rolled (forged couplings are bored and threaded). Ends are chamfered, rust preventive oil applied, and inspected for thread go/no-go. For socket weld, bore is counterbored.

Shipping Packaging

For export, couplings are packed in wooden crates or on ISPM-15 pallets, each layer separated with foam or cardboard. Threads and socket weld bores are protected with plastic caps or rust preventive oil. Labels include type, size, class, material, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength: Direct manufacturer with forging presses, multi-axis CNC machining centers, and automated threading lines, producing threaded, socket weld, and butt weld couplings from 1/8" to 24" to ASME B16.11, B16.25, EN 10241, GB/T 14383 standards.

2.Quality Assurance: Strict control of material grade, thread form (NPT/BSPT/BSPP/metric), thread gauge acceptance (go/no-go), dimensional accuracy, and pressure rating (Class 2000-6000); 100% thread and bore inspection; hydrostatic testing available.

3.Certifications & Reports: Mill test certificates (MTC) for raw materials and finished couplings with each shipment; third-party inspections (SGS, BV) and NDT reports (MT, PT) available upon request.

4.Customization & Service: Wide material range (carbon steel A105, A234 WPB; stainless steel A182 F304/316; alloy steel F11/F22/F91), all types (full/half/reducing/union/swage nipple), custom thread forms, left-hand threads, NACE MR0175 sour service, and hot-dip galvanizing or zinc plating with fast lead times.

5.Export Packaging: Plastic thread protectors + anti-rust oil + foam layer separation + wooden crates/ISPM-15 pallets + steel strapping + clear labeling for safe sea freight and thread protection.

FAQ

1. How to store pipe couplings to prevent thread damage and corrosion?

Store in dry, clean indoor area on wooden pallets. Keep plastic thread protectors on all threaded ends. For socket weld couplings, cap the bores. Apply rust preventive oil if storing more than 3 months. Avoid stacking heavy items directly on couplings to prevent thread distortion.

2. What is the difference between Class 3000 and Class 6000 threaded couplings?

Class 3000 couplings are rated for higher pressure than Class 2000 but lower than 6000. They have thicker walls and larger hex flats (if applicable) than Class 2000. Class 6000 couplings have heavier wall thickness, used for extremely high pressure (e.g., hydraulic lines, steam). Choose based on design pressure and pipe schedule. For most general industrial applications up to 3000 psi, Class 3000 is sufficient.

3. When should I use a full coupling vs a half coupling?

Full coupling joins two pipe ends together (like a connector). Half coupling has only one threaded or socket end and is welded onto the outside of a larger pipe to create a branch outlet (often used with a nipple or threaded valve). Use half coupling for tapping or branch connections where you do not need to join two separate pipe runs.