Key facts
- Size range: 1/2″ – 4″
- Pressure class: CL150 – CL1500
- Face type: RF / RTJ
- Standard: ASME B16.5
- Connection: Socket weld, single fillet
- Material: ASTM A105, A350 LF2, A182 F316L
Socket Weld Flange — Overview
The socket weld flange has a recessed bore. The pipe drops into the socket and a single fillet weld seals it from the outside, which keeps the joint compact and strong on small-bore lines.
It is common on high-pressure small-bore piping such as instrument and drain lines, where a butt weld would be hard to align.
A small gap is left at the bottom of the socket during welding so the pipe can expand without cracking the weld.
Socket Weld Flange Specification
Standard range below. Anything outside it can be quoted on request — send the size, class and quantity you need.
| Standard | ASME B16.5 |
|---|---|
| Size range | 1/2″ to 4″ |
| Pressure class | CL150, 300, 600, 900, 1500 |
| Face type | Raised face (RF), ring joint (RTJ) |
| Connection | Socket weld, one outer fillet weld |
| Material grades | A105, A350 LF2, A182 F304/L, F316/L |
| Surface | Anti-rust oil or black paint |
| Marking | Size, class, standard and heat number on the rim |
| Packing | Fumigated wooden cases, seaworthy marking |
| Certificate | EN 10204 3.1 mill test certificate |
Material Grades We Stock
Carbon, low-temperature, alloy and stainless grades, all supplied with an EN 10204 3.1 mill test certificate.
Where It Is Used
The three project types that order this item most often.
Oil & Gas
Upstream and midstream lines, wellhead hook-ups and pipeline tie-ins where pressure classes run high.
Water & Desalination
Desalination plants, pumping stations and water transmission lines, in carbon or stainless steel.
Power & Process
Power plants, refineries and chemical process piping where heat resistance and traceability matter.
Send Us Your Specification
Size, standard, class and quantity is all we need. You will have prices, lead time and packing details within one working day.