Tesco Steel & Engineering manufactures SWRTJ flanges — Socket Weld Ring-Type-Joint flanges that combine a socket-weld pipe connection with a ring-type-joint (RTJ) face. The face carries a deep machined groove in which a metal ring gasket seats, giving a metal-to-metal seal for high-pressure and high-temperature small-bore lines. The pipe is socket-welded into the bore for a strong, easy small-pipe connection. SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy. Class 150 to 2500, PN1 to PN400. ISO 9001:2015 certified. Made in India.
SWRTJ — Socket Weld Ring-Type-Joint Flange
SWRTJ flanges marry the strength of a socket-weld joint with the sealing of an RTJ face. Tesco Steel & Engineering manufactures them to ASME B16.5 in the full material range — see our socket-weld flanges, the RTJ gasket size chart, and the flange dimensions charts.
Socket-Weld Connection
| Criterion | SWRTJ (Ring-Type Joint) | Socket-Weld RF (Raised Face) |
|---|---|---|
| Seal | Metal-to-metal (metal ring in groove) | Soft / spiral gasket on a flat face |
| Pressure / temperature | Very high — superior sealing | Moderate |
| Gasket blow-out | Confined ring — resists blow-out | Gasket can extrude / blow out |
| Pipe connection | Socket weld (small bore) | Socket weld (small bore) |
| Best for | HP/HT & critical small-bore lines | General lower-pressure lines |
| SWRTJ Flanges are available in the following specifications: | |
|---|---|
| Size | 1/2"NB to 56"NB |
| Class | 150#, 300#, 3000#, 6000#, 9000# |
| Pressure Ratings | PN 1 - PN 400 |
| Stainless Steel SWRTJ Flanges | ASTM A 182 F - 304 / 304H / 304L / 316 / 316H / 316L / 316Ti, 309, 310, 317L, 321, 347, 904L |
| Duplex Steel SWRTJ Flanges | ASTM A 182 - F 51, F 53, F 55 |
| Alloy Steel SWRTJ Flanges | ASTM A 182 - F5, F9, F11, F21, F22 & F91 |
| Carbon Steel SWRTJ Flanges | ASTM A 105 |
| Low Temp. SWRTJ Flanges (LTCS SWRTJ Flanges) | A 350 LF2 |
| Copper Nickel (Cu-Ni) SWRTJ Flanges | C70600, 90/10, C71500, 70/30, C71640 |
| Nickel SWRTJ Flanges | UNS N02200, UNS N02201 |
| Monel SWRTJ Flanges | UNS N04400, UNS N05500, Alloy 20 |
| Inconel SWRTJ Flanges | UNS N06600, UNS N06601, UNS N06625, UNS N08800, UNS N08810, UNS N08825 |
| Hastelloy SWRTJ Flanges | UNS N10276, UNS N06022, UNS N10665, UNS N06455 |
| Titanium SWRTJ Flanges | Gr. 1, Gr. 2, Gr. 3, DTH 3.7035, DTH 3.7055 |
| Other Services | Hot Dip Galvanized (GI) SWRTJ Flanges Sand Blasting on SWRTJ Flanges Shot Peening on SWRTJ Flanges Epoxy Coating on SWRTJ Flanges FBE Coating on SWRTJ Flanges |
Select a pressure class below for its detailed SWRTJ flange dimensions:
| ANSI / ASME Class 150 Flange SWRTJ |
| ANSI / ASME Class 300 Flange SWRTJ |
| ANSI / ASME Class 600 Flange SWRTJ |
| ANSI / ASME Class 1500 Flange SWRTJ |
Deep ring groove and metal ring gasket give a leak-tight metal-to-metal seal for high pressure and temperature.
Socket-weld bore makes a strong, easy connection to small-bore pipe where a butt weld is impractical.
SS 304/316/321, Duplex, Monel, Inconel, and Hastelloy for corrosive and high-temperature service.
Flange to ASME B16.5 with R / RX / BX ring grooves to ASME B16.20, Class 150 to 2500.
The confined metal ring resists gasket blow-out — preferred for hazardous and critical service.
Made to ASME B16.5 or your drawing — class, ring number, and material — certified with EN 10204 3.1 MTC.
| Material | Properties | Typical Use |
|---|---|---|
| A105 Carbon Steel / A350 LF2 (LTCS) | Strong, economical; LF2 for low temp | Non-corrosive & low-temperature HP lines |
| SS 304 / 316 / 321 | Good corrosion resistance; 321 high-temp | Process, chemical & high-temperature service |
| Duplex 2205 / Super Duplex 2507 | High strength & chloride resistance | Seawater & offshore HP lines |
| Monel 400 / Inconel | Excellent in HF, marine & high-temp | HF, seawater & high-temperature service |
| Hastelloy | Superior acid resistance | Aggressive chemical service |
| Industry | Typical Use | Why SWRTJ |
|---|---|---|
| Oil & Gas | HP small-bore & instrument lines | Metal-to-metal seal; socket-weld small bore |
| Refinery & Petrochemical | High-pressure process connections | RTJ sealing; full material range |
| Power Generation | High-pressure steam lines | SS 321; metal ring at high temperature |
| Chemical Plants | Corrosive HP small-bore lines | Monel / Inconel / Hastelloy |
| Hydraulics & Test Rigs | High-pressure small-bore joints | Strong socket weld + RTJ seal |
| Gas Processing | HP gas connections | Blow-out-resistant metal ring |
| Offshore & Marine | Topside HP small-bore lines | Duplex; metal-to-metal seal |
| Instrumentation | HP gauge & impulse lines | Leak-tight small-bore RTJ |
Q1. What is an SWRTJ flange?
SWRTJ stands for Socket Weld Ring-Type-Joint flange. It combines a socket-weld pipe connection with a ring-type-joint (RTJ) face that has a deep groove holding a metal ring gasket. Bolting two RTJ flanges together compresses the metal ring for a metal-to-metal seal that holds at very high pressure and temperature on small-bore lines.
Q2. Why does an SWRTJ flange have a deep groove?
The deep groove on the face holds a solid metal ring gasket (R, RX, or BX type). When the flanges are bolted up, the ring is compressed in the grooves to make a metal-to-metal seal. This is far more leak-tight at high pressure and temperature than a soft gasket on a flat raised face, and the confined ring resists blow-out.
Q3. How is the pipe connected to an SWRTJ flange?
By a socket weld: the small-bore pipe is inserted into the socket bore of the flange, set back about 1.5 mm from the bottom to allow for expansion, and fillet-welded. The socket weld is strong and easy for small-bore pipe where a butt weld would be impractical.
Q4. When should I use an SWRTJ flange instead of a socket-weld raised-face flange?
Use SWRTJ where high pressure, high temperature, hazardous media, or critical service demand a metal-to-metal seal that will not blow out. A socket-weld raised-face (SWRF) flange with a soft/spiral gasket is fine for general lower-pressure lines; the RTJ face is for the more demanding duty.
Q5. What classes and ring types are available?
Class 150 to 2500 (PN1 to PN400), with R (oval/octagonal), RX, and BX ring grooves to ASME B16.20 and the flange to ASME B16.5. Select the class above for the detailed SWRTJ dimensions; the ring number is matched to the flange size and class.
Q6. What materials are SWRTJ flanges made from?
A105/LTCS, SS 304/316/321, Duplex 2205/2507, Monel, Inconel, and Hastelloy. The grade is chosen for the fluid, pressure, and temperature — for example SS 321 for high-temperature steam and Monel/Inconel/Hastelloy for corrosive high-pressure service.
Q7. Can the metal ring gasket be reused?
No. A new, undamaged metal ring of the correct number should be used at every make-up, seated in clean, undamaged grooves. A re-used or deformed ring will not seal reliably. Do not mix ring types (R/RX/BX) — the ring must match the flange groove.
Q8. Can SWRTJ flanges be supplied to our drawing and certified?
Yes. We supply SWRTJ flanges to ASME B16.5 / B16.20 or your drawing — size, class, ring number, and material — with EN 10204 3.1 material test certificates on request. Send your line details and service conditions for a quote.