Both are ASME B16.20 R‑type gaskets with the same R numbers. Their key differences lie in cross‑section geometry.
Oval type – Features a curved elliptical cross-section, forming line contact with the flange groove. It delivers higher unit load and is more forgiving of flange misalignment. This type is better suited for retrofitting old flanges with round-bottom grooves. However, it has a higher manufacturing cost.
Octagonal type – Boasts eight flat sealing faces, achieving surface contact with the groove. It offers more uniform stress distribution and superior leakage resistance. Additionally, it is easier to machine and has a lower production cost.
Selection Guide: For new projects → octagonal type is preferred. For retrofitting old flanges with round-bottom grooves → oval type is recommended. For API 6A wellhead applications → follow the project’s specific flange specification.
There are many types of RTJ gaskets, including R Gasket,RX Gasket,BX Gasket, SBX Gasket,IX Gasket,flange connections,and various customized products.We will do more sharing about ring joint gasket.
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