The ring type joint was initially developed 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.

The Style R ring type joint is manufactured in accordance with API 6A and ASME B 16.20, to suit API 6B and ASME B 16.5 flanges.
Style R ring type joints are manufactured in both oval and octagonal configurations.

Both styles are interchangeable on the modern flat bottom groove, however only the oval style can be used in the old type round bottom groove.
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.
Style RX ring type joint is a pressure energized adaptation of the Style R ring type joint. The Style RX is designed to fit the modern flat bottom groove, and is interchangeable with the standard Style R ring type joint. However, since the Style RX is significantly taller than a Style R, larger flange make up distances will result.

Style RX ring type joints are designed to seal pressures 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 design uses a pressure energized effect which improves the efficiency of the seal as the internal pressure of the system increases. Selected sizes incorporate a pressure passage hole to allow for pressure equalization each side of the sealing faces.

The Style BX ring type joint is manufactured in accordance with API 6A.
The Style BX ring type joint design exhibits a pressure energized effect which improves the efficiency of the seal as the internal pressure of the system increases. 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 face 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.

NOTE: Style SBX and SRX rings are manufactured in accordance with API 17D for use on subsea wellhead and Christmas tree equipment.