SS316L Ring Joint Gasket – ASME B16.20 / API 6A – RTJ Gasket Manufacturer & Supplier
We are a professional manufacturer and global supplier of SS316L ring joint gaskets designed in accordance with ASME B16.20 and API 6A standards. Our ring-type joint (RTJ) gaskets offer excellent sealing performance for high-pressure, high-temperature applications in the oil & gas, petrochemical, refinery, and power generation industries.
Made from high-purity 316L stainless steel, these gaskets provide superior corrosion resistance and long-term durability in aggressive service conditions, including sour gas (H₂S), seawater, and chloride-containing environments.
Ring Joint gaskets are available in octagonal or oval .Ring gaskets are widely used in Refineries, Petrochemical Industries, drilling well head equipment, Pressure Vessels, valves, Christmas Tree valves and Pipe lines. Our ring joint gaskets are strictly manufactured as per API-6A and ASME B16.20 specification.
SS316L Ring Gasket Technical Specifications
| Product | Ring Type Joint Gasket (RTJ) |
|---|---|
| Standard | ASME B16.20 / API 6A |
| Material | Stainless Steel 316L (UNS S31603) |
| Hardness | ≤ 160 HB (per ASME/API requirement) |
| Types Available | R, RX, BX Types |
| Size Range | 1/2″ to 24″ (and custom sizes) |
| Pressure Classes | Class 150 to 2500 (ASME), 2000 to 20000 PSI (API) |
| Surface Finish | Ra 1.6–3.2 μm (machined serration) |
| Certifications | EN 10204 3.1, NACE MR0175, ISO 9001 |
SS316L Oval ring-joint gasket
Oval Ring gasket is manufactured in an oval-shaped section. The oval ring fits the round and flat bottom ring groove flange
The original ring joint design can be used on standard flat bottomed groove flanges and older round bottomed groove flanges Can be used for ASME B16.5 flange class 150 to 2500 and API 6B to Class 5000 Soft iron and carbon steel gaskets are zinc plated to prevent corrosion All rings are marked with the ring number,material and the date of manufacture and API designation.
SS316L Octagonal ring-joint gasket
An Octagonal RTJ Gasket is a metal ring with an 8-sided cross-section, engineered to fit into a machined groove on RTJ (Ring Type Joint) flanges. When bolted, the gasket deforms slightly to form a metal-to-metal seal, ensuring leak-tight performance under extreme conditions.
Chemical Composition of SS316L Ring gasket (UNS S31603)
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.030 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Silicon (Si) | ≤ 0.75 |
| Chromium (Cr) | 16.0 – 18.0 |
| Nickel (Ni) | 10.0 – 14.0 |
| Molybdenum (Mo) | 2.0 – 3.0 |
| Iron (Fe) | Balance |
SS316L has low carbon content, which improves weldability and resistance to intergranular corrosion.
Mechanical Properties of SS316L (at room temperature)
| Property | Value |
|---|---|
| Tensile Strength | ≥ 485 MPa (70 ksi) |
| Yield Strength (0.2% offset) | ≥ 170 MPa (25 ksi) |
| Elongation (in 50 mm) | ≥ 40% |
Typically Hardness of SS316L ring gasket: ≤ 160 HB
SS316 Ring gasket Hardness requirement
| Scale | Maximum Value |
|---|---|
| Brinell (HBW) | Typically ≤ 160 HB (per API 6A / ASME B16.20 recommendation for ring gaskets) |
| Rockwell B | Approx. 80–95 HRB |
RTJ gaskets dimension and weight list
Pls check and download the RTJ gaskets dimension and weight list
The gasket material is selected on a number of grounds primarily; chemical compatibility with the media and the hardness of the flange. The gasket material ideally needs to be less than the flange material to ensure sufficient deformation of the gasket without damaging the flange facing. Some common materials are listed in the table below.
Applications of Oval Ring-Joint Gaskets
Oil & Gas Pipelines – Wellhead assemblies, Christmas trees, subsea connections
Refineries & Petrochemicals – Heat exchangers, pressure vessels, reactors
Power Plants – High-pressure steam, turbines, and boilers
Aerospace & Defense – Jet engines and high-temperature exhaust systems
Nuclear Industry – Radiation shielding & reactor coolant piping

SS316L Ring gasket Compliance & Quality
- Manufactured in accordance with ASME B16.20 and API 6A
- Suitable for API 6A Type 6B & 6BX flanges
- Full traceability with heat number marking and material certification
- Optional electropolishing, silver plating, or PTFE coating
Typical Description of 316L Oval Ring Gasket
Product Name: SS 316L Oval Ring Joint Gasket
Size: 1-1/2 Inch, DN40
Pressure: Class 2500 LB, PN420
Standard: ASME B16.20
Material: Stainless Steel SS 316L
Max Hardness: HB 135


