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Ring Joint Gasket

DELTAONE manufactures and supplies a large variety of ring joint gaskets. The RTJ standard size gaskets are manufactured in accordance to API-6A and ASME B16.20 specifications.


API ring Joint gaskets come in two basic types, an oval cross section and an octagonal cross section. These basic shapes are used in pressures up to 10,000 DELTAONE. The dimensions are standardized and require specially grooved flanges. The octagonal cross section has a higher sealing efficiency than the oval and would be the preferred gasket. However, only the oval cross section can be used in the old type round bottom groove. The newer flat bottom groove design will accept either the oval or the octagonal cross section. The sealing surfaces on the ring joint grooves must be smoothly finished to 63 micro inches and to be free of objectionable ridges, tool or chatter marks. They seal by an initial line contact or a edging action as the compressive forces are applied.

The hardness of the ring should always be less than the hardness of the flanges to prevent flange deformation. Dimensions for API ring joint gaskets and grooves are covered in ASME B16.20 and API6A

DELTAONE stocks a wide range of sizes and materials ready for immediate shipment from R11 to R105. Stock materials include large variety of metals.


The BX ring gasket differs from the standard oval or octagonal shape since it is square in cross section and tapers in each corner. They can only be used in API 6BX flanges. BX is used at pressures up to 15,000 DELTAONE. Standard sizes are stocked in low carbon steel, 304 and 316.


RX ring gaskets are similar in shape to the standard octagonal ring joint gasket but their cross section is designed to take advantage of the contained fluid pressure in effecting a seal. They are both made to API 6A and interchangeable with standard octagonal rings for oil field drilling and production applications in API 6B flanges. RX is used at pressures up to 15,000 DELTAONE. Standard sizes are stocked in low carbon steel, 304 and 316.