A special fitting in a Stage I vapor recovery system that is installed at the top of the vapor recovery riser in two-point and manifolded Stage I vapor recovery systems. The vapor recovery adaptor mates to the vapor recovery elbow attached by the fuel delivery driver prior to a delivery.
Some adaptors incorporate a swivel feature that allows the vapor recovery elbow to rotate on a vertical axis, thus preventing the loosening of the adaptor from the riser because of the movement of the vapor recovery hose.
The adaptor includes a spring loaded poppet that remains closed until the driver attaches the vapor recovery elbow. An orange dust cap is placed on the adaptor between fuel deliveries to keep the poppet clean and identify the adaptor as a vapor recovery fitting.
See also PEI/RP300.