Jonny C
Member
I was given a very nice airspeed indicator made by Meggitt - it was a spare from a military helicopter which was never installed. As it's ex-military I can't get hold of its installation manual.
It doesn't have standard 1/8" NPT threads for its ports. The dimensions I measure (for the female threads) are 0.390" (about 9.90 mm). This is between 1/8 and 1/4" NPT (and BSP) threads, and doesn't seem to be a metric one either.
Has anybody seen an SAE 1/4" thread used on things like this? The port diameters seem to agree with this SAE thread which, apparently, is always used with an O ring for sealing. The chamfer looks like it could be for seating a rubbery O ring.
Has anybody seen anything like this before? Maybe I should see if I can get hold of a plastic SAE barb to test so at least I won't ruin the threads.
It doesn't have standard 1/8" NPT threads for its ports. The dimensions I measure (for the female threads) are 0.390" (about 9.90 mm). This is between 1/8 and 1/4" NPT (and BSP) threads, and doesn't seem to be a metric one either.
Has anybody seen an SAE 1/4" thread used on things like this? The port diameters seem to agree with this SAE thread which, apparently, is always used with an O ring for sealing. The chamfer looks like it could be for seating a rubbery O ring.
Has anybody seen anything like this before? Maybe I should see if I can get hold of a plastic SAE barb to test so at least I won't ruin the threads.
