Ring Joint Gaskets

From www.gasketwiki.com

A solid metal gasket that is highly polised and softer than the flange material.  The gasket is actually ‘crushed’ into flange (coining & intimate contact), creating a seal by filling imperfections and leak paths with gasket material.  Under high sealing stress the gasket will deforms but the flange will not.  They are used predominantly in the petrochemical industry (offshore oil platforms, refineries) due to the high service pressures required in their processes.  Ring joing gaskets are precision engineered and machined to exact specifications with tight tolerances(ASME B16.20, API 6A).

Contents 1 Styles 2 Design Pressure 3 Materials 4 Handling and Storage

Styles

R      Oval or octagonal style of gasket

RX    Self-energizing style of gasket

BX    Used in API spec 6A flanges that have ring grooves machined into them to accept this style of gasket

SRX  Similar to the RX style gasket with special vent holes to allow water to escape in subsea applications

SBX  Similar to the BX style gasket with special vent holes to allow water to escape in subsea applications 

Design Pressure

Gasket Style	Pressure
R	10,000 psi
RX	15,000 psi
BX	20,000 psi

Materials

Ring joing gaskets are commonly made out of the following materials:

• Soft Iron
• Low Carbon Steel
• Stainless Steel
• Monel®
• Inconel®
• Incoloy®
• Hastelloy®
  
  

Soft iron and low carbon steel Ring Joint gaskets are protected with electroplated cadmium to a maximum thickness of 0.0005” according to API specifications to provide a protective coating.

Handling and Storage

It is important to use proper packaging, handling and storage methods as any bruise, gouge (dent, ding, etc.) or groove across the seal contact area may prevent uniform coining and continuous intimate contact, resulting in leakage in the area of damage.  Any rough handling or impact contact against hard surfaces or objects may cause damage to a ring gasket that renders it unusable.  Soft iron and carbon steel ring gaskets must be kept dry to prevent rust and pitting.

The plating on these ring gaskets will provide some rust protection for a short time but any extended storage in a damp atmosphere or wetness may destroy the usefulness of these gaskets.  Stainless steel ring joint gaskets are more tolerant to wet and damp conditions.