Ring Joint Gasket Catalogue - ASME B16.20
Metallic ring joint gasket solutions for high pressure and temperature applications
Ring Gasket Types
ASME B16.20 Standard
R Type Oval Ring Gasket
Standard oval section ring joint gasket designed for high-pressure applications.
Compatible Flanges:
ASME B16.20 Standard Dimensions
| Nominal Size | Outside Dia (mm) | Inside Dia (mm) | Width (mm) | Groove Type |
|---|---|---|---|---|
| 1" | 60.5 | 35.1 | 11.2 | R-11 |
| 2" | 79.2 | 53.8 | 11.2 | R-11 |
| 4" | 127.0 | 101.6 | 11.2 | R-11 |
| 8" | 200.2 | 174.8 | 11.2 | R-11 |
| 12" | 269.9 | 244.5 | 11.2 | R-11 |
| 16" | 330.2 | 304.8 | 11.2 | R-11 |
Key Features
- Oval section design
- High pressure resistance
- Excellent sealing performance
- Easy installation
- Standard dimensions
- Long service life
Applications
- Petrochemical plants
- High pressure pipelines
- Power generation
- Offshore platforms
- Compressor stations
- Critical process systems
Sealing Performance
Design Features
- Oval section geometry
- Controlled compression
- Metal-to-metal sealing
- High contact pressure
- Corrosion resistant
- Test certified
Technical Notes
- Flange surface finish should be Ra 3.2–6.3 μm.
- Cleaning before assembly is critical.
- Compression rate should be between 15–20%.
- Re-use requires inspection and approval.
Related Sectors
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Detailed Technical Information and Quotation
Contact our expert team for detailed technical documents, application recommendations, and custom size quotations regarding this product type.
Get Technical SupportWhat is a ring joint gasket (RTJ)?
A ring joint gasket (RTJ) is a metallic sealing ring that seals flange connections at high pressure and temperature. The R series (oval and octagonal cross-sections) is made to ASME B16.20; the pressure-energized BX and RX series to API 6A. It is used with RTJ-faced flanges in pressure classes 150#–2500#.
How RTJ gaskets work and which type goes where
The RTJ gasket sits in a trapezoidal groove machined into the flange face; as the bolts are tightened the ring deforms plastically, creating line contact against the groove walls — a metal-to-metal joint that stays tight even at very high pressure. The gasket material is therefore always chosen softer than the flange (soft iron, low-carbon steel, 304/316 stainless, alloys): the gasket must deform, not the groove. The oval section also suits older round-bottom grooves; the octagonal section seals better in modern flat-bottom grooves. RX is a pressure-energized type that fits the standard R groove; BX serves API 6A wellhead and christmas-tree applications up to 20,000 psi. RTJ gaskets are standard in oil & gas, refining and petrochemicals.
Frequently Asked Questions
Oval vs octagonal ring gasket — what is the difference?+
They differ in cross-section: oval also fits older round-bottom grooves; octagonal gives wider contact and a better seal in modern flat-bottom grooves. Both are R-series and share the same groove dimensions (B16.20).
Where are BX ring gaskets used?+
BX is for high-pressure API 6A wellhead and christmas-tree flanges; it provides pressure-energized sealing up to 20,000 psi and fits only BX-grooved flanges.
Can an RTJ gasket be reused?+
No. Sealing relies on plastic deformation of the ring, so a removed gasket has lost its dimensions and surface finish; a new gasket is fitted at every assembly.
How is RTJ gasket material selected?+
The gasket must be softer than the flange so deformation happens in the gasket, not the groove. Typical picks: soft iron/low-carbon steel for carbon steel flanges, 304/316 for stainless systems, suitable alloys for corrosive service.
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