Threaded & Socket-Weld Stainless Steel Fittings: Best Solutions for Small-Bore Piping

Introduction: Connection Method Determines Installation Efficiency
In small-bore piping systems (DN50 and below), threaded and socket-weld connections are the two most common joining methods. Threaded fittings require no welding, enabling quick installation and removal — ideal for instrument tubing and sampling systems requiring frequent maintenance. Socket-weld fittings provide compact, high-integrity joints suitable for high-pressure, high-temperature service. Wenqiang Stainless Steel supplies NPT/BSP threaded and socket-weld fittings in complete small-bore ranges.

Threaded Fittings: Features & Applications
Wenqiang's threaded fittings comply with ASME B16.11 and GB/T 14626, available in NPT (American taper pipe thread), BSP (British Standard pipe thread), and R/Rc (taper/parallel) thread forms. Materials: primarily 304/316L. Pressure classes: 2000#, 3000#, 6000#.
The primary advantage of threaded fittings is elimination of hot work — essential in explosive atmospheres and for online maintenance. However, pressure capacity and sealing reliability are lower than welded connections, suitable for medium-low pressure (≤6 MPa) ambient temperature service.

Socket-Weld Fittings: Features & Applications
Socket-weld fittings involve inserting the pipe end into the fitting's socket and applying a fillet weld. Joint strength exceeds threaded connections, and the compact profile is smaller than butt-weld fittings. Wenqiang's socket-weld fittings comply with ASME B16.11 in pressure classes 3000#, 6000#, and 9000#.
Socket-weld is ideal for DN40 and below with working pressures ≤10 MPa in high-temperature, high-pressure piping such as instrument impulse lines, sampling lines, and analyzer tubing.

Frequently Asked Questions
Q1: Can NPT and BSP threads be interconnected?
A: No. NPT uses 60° taper threads while BSP uses 55° threads (parallel BSPP and taper BSPT) with different thread pitch. Forced connection causes seal failure and thread damage. Wenqiang can supply NPT/BSP conversion adapters.
Q2: Do threaded fittings require thread sealant?
A: Yes. Stainless steel threaded connections typically require PTFE tape or thread sealant compound. Avoid copper- or graphite-based sealants to prevent galvanic corrosion with stainless steel.
Q3: What is the MOQ for Wenqiang threaded fittings?
A: Standard specifications (1/2"-2", 304/316L): single piece minimum, ample stock. Non-standard specifications: 5-10 day lead time.

Contact Us
Wenqiang Stainless Steel threaded and socket-weld fittings — small bore, big reliability. NPT/BSP full range in stock. Inquiries: +86 577 8922 2595.