ASME B16.20 Ring Type Joint Gasket (RTJ) Specification
Metal Ring Type Joint (RTJ) Gaskets for High-Pressure Flange Connections | Technical Specification PDF Download
The ASME B16.20 Ring Type Joint (RTJ) Gasket Specification provides a comprehensive technical reference for metallic RTJ gaskets used in high-pressure and high-temperature flange connections. This specification covers gasket types, materials, dimensions, tolerances, manufacturing requirements, inspection criteria, and typical applications in oil & gas, petrochemical, refinery, and offshore piping systems.
ASME B16.20 Standard Overview
ASME B16.20 is the standard specification for metallic gaskets used with pipe flanges and flanged fittings. It covers ring type joint (RTJ) gaskets, spiral wound gaskets, and jacketed gaskets.
Ring Type Joint gaskets manufactured in accordance with ASME B16.20 are specifically designed for high-pressure, high-temperature service and are commonly used with ASME B16.5 and ASME B16.47 flanges.
Product Type: Ring Type Joint (RTJ) Gasket
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Standard: ASME B16.20
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Gasket Type: Ring Type Joint (RTJ)
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Gasket Construction: Solid Metal
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Application: High-Pressure Flange Sealing
RTJ gaskets provide metal-to-metal sealing by deforming into the flange groove under bolt load, creating a highly reliable seal.
RTJ Gasket Types
ASME B16.20 defines several RTJ gasket styles, including:
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R Type – Oval and Octagonal cross sections
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RX Type – Modified pressure-energized design
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BX Type – High-pressure pressure-energized gasket
Each gasket type is designed to match specific flange groove profiles and pressure ratings.
Materials for RTJ Gaskets
Common materials specified under ASME B16.20 include:
| Common Materials | |||
|---|---|---|---|
| Material | Brinell Hardness | Temperature Limitations | Identification |
| Soft Iron | 90 | -60 to +400 °C | D |
| Low carbon steel | 120 | -40 to +500°C | S |
| 4%-6% Cr ½% Mo:F5 | 130 | -125 to +500°C | F5 |
| Stainless steel 304/304L | 160 | -250 to +650°C | S304 or 304L |
| Stainless steel 316/316L | 160 | -196 to +800°C | S316 or 316L |
| Stainless steel 321 | 160 | -250 to +870°C | S321 |
| Stainless steel 347 | 160 | -250 to +870°C | S347 |
| Stainless steel 410 | 170 | -20 to +500°C | S410 |
| Inconel 625 | – | 1000°C | 625 |
| Incoloy 825 | – | 1000°C | 825 |
| Hastelloy C-276 | – | 1000°C | C-276 |
| Duplex | – | 800°C | S31803 |
| Titanium | – | 540°C | TI |
The sealing surfaces on the ring joint grooves must be smoothly finished to 63 Microinches and be free of objectionable ridges, tool or chatter marks.
Dimensions & Tolerances
RTJ gasket dimensions and tolerances are strictly defined by ASME B16.20 to ensure proper fit and sealing performance.
Dimensional requirements include:
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Outside diameter (OD)
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Inside diameter (ID)
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Gasket height
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Groove compatibility
RTJ gaskets are designed to match ASME B16.5 and ASME B16.47 flange groove dimensions.
Manufacturing Requirements
ASME B16.20 RTJ gaskets are manufactured by:
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Precision machining
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Controlled heat treatment (if required by material)
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Surface finishing to specified roughness
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Dimensional and visual inspection
Strict manufacturing control ensures consistent sealing performance in critical service conditions.
Testing & Inspection
Each RTJ gasket may be subjected to:
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Material verification
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Dimensional inspection
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Visual inspection
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Hardness testing (when specified)
Certificates of compliance are typically supplied upon request.
Applications
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Oil & Gas Pipelines
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Refineries
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Petrochemical Plants
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Offshore Platforms
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High-Pressure Process Piping
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Subsea and Critical Service Systems
ASME B16.20 RTJ gaskets are widely used where maximum sealing reliability is required.
Download ASME B16.20 RTJ Gasket Specification PDF
Download the complete ASME B16.20 Ring Type Joint Gasket Specification PDF, including gasket types, material requirements, dimensions, and inspection criteria.
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👉 Download ASME B16.20 standard specification pdf
Related Products:
ASME B16.20 Inconel 625 Ring gasket
ASME B16.20 Incoloy 825 Ring gasket