Ring Joint Gasket

Short delivery time, good quality and best after sale service, these are the reasons you can cooperate with us for the ring joint gaskets. The ring joint gaskets play important roles in now oil & gas industry. Below text we can know more about the gaskets, and if you need more information not listed please contact us.

Welcome to Know Ring Joint Gasket

Ring joint gasket is manufactured from metal materials in compliance with ASME B 16.20 and the API specification. This type gasket has two basic types oval and octagonal, including R, RX, BX, SBX, SRX, IX Norsok type.

Ring joint gasket is used in connection with RTJ flange, as it can generate a strong seal between two mating flanges. When the flanges are fixed by bolts, ring joint gasket is squeezed into the groove of the flange, forming a tight seal between the mating flanges. In order to avoid destruction of the flanges, the material of the ring joint gasket must be softer than the material of the flanges.

Types of Ring Joint Gasket

It has many types like R type oval and octagonal, RX, BX, SBX, SRX, IX Norsok. Below text we will know the details.

R Type Octagonal Ring Gasket

R type octagonal ring gasket has the octagonal-shaped section. The average diameter of the R octagonal gasket is slightly larger than the average diameter of the gasket groove. The angle between ring gasket and bevel face of gasket groove is around 23°, and the octagonal shape fits only the modern flat bottom groove flange.

Octagonal RTJ Drawing

R Type Oval Ring Gasket

Oval ring type gasket is manufactured in oval shaped section. The oval ring type joint gasket fits the round and flat bottom ring groove flange. R octagonal gasket and R oval ring gasket have a similar function, as they all seal by an initial line contact or a edging action as the compressive forces are applied. However, the R oval ring gasket has a lower sealing efficiency than the octagonal.

This image is about what the Oval RTJ gasket looks like

BX Ring Gaskets

The style 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 (1,360 bar) in accordance with API 6A pressure ratings.

drawing for BX Ring Joint Gasket

RX Ring Gasket

RX ring gasket is designed for pressures up to approx. 10,000 psi (700 bar). This is self-sealing that uses a pressure-energised effect.

The Style RX 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. The Style RX is designed to fit the modem flat bottom groove, and is inter-changeable 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 (425 bar) in accordance with ASME B16.5 pressure ratings, and up to 5,000 PSI (340 bar) in accordance with API 6A pressure ratings.

drawing for RX Ring Joint Gasket


  • Suitable for extreme pressure and temperature requirements
  • Metal-to-metal contact creates a reliable seal
  • Certified quality (including surface hardness

Recommended application

  • Petrochemical industry
  • Flange connections
  • Oil & gas industry
  • Pipe connections
  • Industries

Protective Coating

As the carbon steel and soft iron are easy to be rusted, as a result the soft iron and low carbon steel ring type joint gaskets are often protected with electroplated zinc to a maximum thickness of 8μm. Alternative material coatings like PTFE also is a choice.

This image we can see the ring joint gasket with zinc plated

Ring Joint Gasket Materials Chart

The ring joint gasket materials should be selected to suit the service conditions. It is always recommended that the gasket material should be softer than the mating flanges. The maximum hardness and identification of ring type joints as specified in API 6A and ASME B16.20.

And for highly critical applications, ring type joints can be machined from Duplex steels and other exotic materials such as Inconel®, Incoloy®, and Hastelloy®. The Technical Department is available to advise on other materials.
MaterialsUNS NumberMax Hardness BrinellMax Hardness RockwellAbbreviation
Soft Iron-9056D
Low Carbon Steel-12068S
AISI 304S3040016083S304
AISI 316S3160016083S316
AISI 347S3470016083S347
AISI 410S4100017086S410
Alloy 600N0660020092UNS Number
Alloy 625 N0662520092UNS Number
Alloy 800N0880020092UNS Number
Alloy 825N0882520092UNS Number
Hastelloy C276N1027620092UNS Number
DuplexS31803250-UNS Number
Super DuplexS3276020092UNS Number
Monel 400N0440020092UNS Number
Titanium Gr.2R5040021594UNS Number