RTJ Gaskets are originally meant for use in the petroleum industry, where high pressure/temperature applications necessitated the need for a high integrity seal. They are mainly used in the oil field on drilling and completion equipment. Ring type joints are also commonly used on valves and pipework assemblies, along with some high integrity pressure vessel joints
Ring type joint gaskets are manufactured in accordance with API-6A and ANSI B16.2 specifications. API ring joints come in two basic types, oval and an octagonal shape. These basic shapes are used in pressures up to 10,000 psi. 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. RTJ's have "R" numbers assigned to them for pipe size and pressure class identification.
RTJ Gasket Materials :
304 / 304 L Stainless Steel
316 / 316 L Stainless Steel
321 Stainless Steel
347 Stainless Steel
410 Stainless Steel
F-5 ( 502 / 501 ) Stainless Steel
Soft Iron “ D “
The Style R ring type joint is manufactured in accordance with API 6A and ASME B16.20, to suit API 6B and ASME B16.5 flanges.
Style R ring type joints are manufactured in both oval and octagonal configurations. 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 Microinches and be free of objectionable ridges, tool or chatter marks. They seal by an initial line contact or a wedging action as the compressive forces are applied. The hardness of the ring should always be less than the hardness of the flanges
Style R ring type joints are designed to seal pressure up to 6,250 psi in accordance with ASME B16.5 pressure ratings and up to 5,000 psi in accordance with API 6A pressure ratings.
The Style RX ring type joint is manufactured in accordance with API 6A and ASME B16.20, to suit API 6B and ASME B16.5 flanges.
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 is effecting a seal. They are both made to API 6A.
The BX ring gasket differs from the standard oval or octagonal shape in that it is square in cross section and tapers in each corner. BX ring type joint is manufactured in accordance with API 6A. All BX ring type joints incorporate a pressure passage hole to allow for pressure equalization each side of the sealing faces. On assembly, metal to metal contact of the flange faces is achieved. The Style BX is not interchangeable with any other style, and is only suited for API 6BX flanges. Style BX ring type joints are designed to seal pressure up to 20,000 psi in accordance with API 6A pressure ratings.
Material Hardness Conversion Chart and Material Hardness
Size Chart for Oval or Octagonal Rings
Dimensions for Oval or Octagonal Rings
RX Gaskets for API 6B Flanges
BX Gaskets for API 6BX Flanges