304 Stainless Steel BSP Full Socket Pipe Coupler — DN8 to DN100

DN (Diameter Nominal) refers to the nominal bore of the pipe, not its outer diameter. Match the DN size to your existing pipe's nominal bore: DN8 = 1/4" BSP, DN10 = 3/8" BSP, DN15 = 1/2" BSP, DN20 = 3/4" BSP, DN25 = 1" BSP, and so on up to DN100 = 4" BSP. When in doubt, measure the outer diameter of your pipe and consult a BSP pipe sizing chart to confirm the correct nominal size before ordering.

304 stainless steel pipe fittings are generally rated for working pressures up to 150 PSI (approximately 10 bar) in standard plumbing applications, though actual pressure ratings vary by pipe size and installation conditions. Larger DN sizes typically have lower pressure ratings. Always verify the pressure rating against your specific system requirements and consult a qualified engineer for high-pressure applications.

Yes. 304 stainless steel offers good corrosion resistance in most outdoor and wet environments, including fresh water, mild chemicals, and general outdoor exposure. It is typically suitable for garden irrigation, outdoor plumbing, and light industrial use. For highly corrosive environments — such as coastal saltwater exposure or aggressive chemical service — 316 stainless steel is generally recommended instead.

These fittings use BSP (British Standard Pipe) threads — specifically G-thread (parallel BSP, ISO 228). BSP is widely used in plumbing, hydraulics, and pneumatics across the UK, Europe, Australia, and Asia. BSP threads are not directly compatible with NPT (National Pipe Thread) used in North America — the thread pitch and angle differ. A dedicated BSP-to-NPT adapter is required if you need to connect to an NPT system.

A full socket (full coupling) has internal BSP threads on both ends, allowing you to join two externally threaded (male BSP) pipe sections end-to-end. A half socket has one threaded end and one plain end (for welding or compression). A union is a three-piece fitting that allows disassembly without rotating the pipes. Use a full socket when both pipe ends are already male-threaded and you simply need to connect them in a straight line.

Yes — thread sealant is generally required for a leak-free connection. PTFE tape (plumber's tape) wrapped clockwise around the male threads is the most common and widely available option. Pipe thread compound (pipe dope) is an alternative for higher-pressure or gas applications. Apply sealant to the male threads only, not inside the socket. Thread sealant is not included with the fitting.

304 stainless steel BSP fittings are in many cases used in gas piping systems. However, gas line installations are subject to local building codes, regulations, and inspection requirements that vary by region. Always consult a licensed plumber or gas fitter and verify compliance with your local codes before using any fitting in a gas application. Do not use PTFE tape alone for gas — use gas-rated thread sealant compound.

For a single pipe joint repair, 1 pc is typically sufficient. If you are running multiple branch connections or extending a pipe run with several joints, the 3-pack or 5-pack offers better value per piece. Many plumbers and maintenance teams order the 5-pack to keep spares on hand, since having the right size coupler available immediately avoids project delays.