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RAO — Round-to-Oval Adapter

How to Specify

Using tables from the National Fuel Gas Code or our Sizing & Application Guide, determine the diameter of venting required. The Sizing & Application Guide also offers tips on good design including multi-appliance system sizing and design.

How to Purchase

Vent FAQs

RAO — Round-to-Oval Adapter


  • The round-to-oval adapter is used for conversion of vent from round to oval.
  • Requires use of RRA female adapter to come from round.

Round-to-Oval Adapter dimensions (inches)

ModelSizeDim. A
4RAO46 7/8
5RA5O59 3/8