Kaxite RX ring joint gasket is a metal-to-metal sealing ring machined from a solid forging on CNC equipment to ASME B16.20 and API 6A. The RX geometry is pressure-activated and drops into the same API 6B flange groove as an R-oval or R-octagonal ring, rated up to 5,000 PSI. It is the standard choice for wellhead, manifold, Christmas tree and high-pressure process flanges where a soft gasket cannot survive the pressure or temperature. RX rings are one element of our full ring joint gaskets range, which also covers R-oval, R-octagonal, BX and lens profiles.
Standard ring joint profiles for conventional ANSI B16.5 and ASME B16.47 Series A flanges. R-octagonal is interchangeable with R-oval on modern grooves and provides slightly better sealing.
Pressure-activated ring geometry for API 6B wellhead and manifold flanges. Interchangeable with R-oval and R-octagonal on the same flange, but rated to a higher pressure ceiling.
Highest-pressure ring family, restricted to API 6BX flanges and 16BX hubs. The BX ring geometry uses a pressure-energised vent hole. See the BX ring joint gasket page for that family.
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| Feature | R-Oval | R-Octagonal | RX |
|---|---|---|---|
| Flange standard | ANSI B16.5, ASME B16.47 Series A | ANSI B16.5, ASME B16.47 Series A | API 6B |
| Cross-section | Oval | Octagonal | Pressure-activated RX profile |
| Typical pressure ceiling | Class 150 – 2,500 | Class 150 – 2,500 | Up to 5,000 PSI |
| Interchangeability | Fits oval grooves | Fits oval or octagonal grooves | Fits R-oval / R-octagonal API 6B grooves; higher pressure rating |
| Typical service | Refinery, chemical, general process | Refinery, chemical, general process | Wellhead, manifold, Christmas tree, high-pressure process |
The RX ring is not a replacement for a BX ring on an API 6BX flange. Compare groove geometry carefully; our API ring joint gasket page covers the full API family, and the oval and octagonal pages detail the R profiles.
RX ring joint gasket after CNC turning and groove finishing, before final marking.
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| Material | Hardness (HB) | Temperature °C | Temperature °F |
|---|---|---|---|
| Soft iron | 90 | -60 to 500 | -76 to 932 |
| Low carbon steel | 120 | -40 to 540 | -40 to 1,004 |
| SS304 | 160 | -250 to 540 | -418 to 1,004 |
| SS304L | 160 | -250 to 540 | -418 to 1,004 |
| SS316 | 160 | -200 to 815 | -328 to 1,499 |
| SS316L | 160 | -200 to 815 | -328 to 1,499 |
| SS321 | 160 | -200 to 870 | -328 to 1,598 |
| SS347 | 160 | -200 to 870 | -328 to 1,598 |
| SS410 | 170 | -200 to 850 | -328 to 1,562 |
| 5Cr-0.5Mo | 130 | -29 to 650 | -20 to 1,202 |
| Inconel 600 | 150 | -100 to 1,095 | -148 to 2,003 |
| Incoloy 825 | 150 | -100 to 1,095 | -148 to 2,003 |
Material selection is usually driven by the working fluid, not only by the pressure class. Sour service, CO2, H2S and chloride content all influence the hardness ceiling and alloy choice. Tell us the media and temperature and Kaxite will return the recommended grade.
Kaxite Sealing machines RX ring joint gaskets in Ningbo, Zhejiang, on the same CNC line that produces R-oval, R-octagonal and BX rings, so a mixed order for a wellhead project can be shipped from one facility. Sizes follow the standard RX table; non-standard groove dimensions and special alloy rings are quoted from drawings. Free samples are available for qualified projects, with the mill certificate attached to the sample shipment. Factory visits and video audits are welcome by appointment; ISO 9001 certificate details are available on request.
Request an RX ring joint gasket quote
Tell us flange size, API 6B pressure class, ring number, material grade and working media. Free samples and mill certificates available for qualified projects.
Send Inquiry →Address
No. 432 Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang China
