Straight Thread O-Ring Boss SAE J1926 : Often called an "SAE" or "ORB" port, this thread style is recommended by the NFPA for leak prevention.
The male connection is a straight thread with an O-ring. The female port has a straight thread and a machined surface to provide a smooth,
flat surface (minimum spot-face), along with a chamfer where the O-ring seats. It seals when the O-ring is compressed into the
chamfer when mating the male connection. This is also considered a mechanical connection.