Ring type joint. Oval or octagonal rings of soft iron, low carbon steel or stainless steel are crushed into matching grooves in both flanges, giving a metal-to-metal seal for high pressure and temperature, wellheads, and hydrogen service. The ring must be softer than the groove, is used only once, and the bolted joint leaves a visible gap between flange faces.
Have the R-45 rings on site before we break the RTJ flanges, and don't let anyone reuse the old ones.
Check the groove for scratches across the sealing surface before you drop in a new ring; a radial scratch is a guaranteed leak.
Also heard as
- ring joint
- R-ring
- ring type joint
Related terms
Raised face
A flange facing where the gasket surface stands slightly proud of the bolt circle area, concentrating gasket load.
Pressure class
The standardized rating step, such as 150, 300 or 600, that sets a valve or flange's allowable pressure at each temperature.
Spiral wound gasket
A flange gasket made of a V-shaped metal strip wound with a soft filler, held between an outer ring and usually an inner ring.