Big Pete wrote:But where do they use Rohr threads?
I don't know about Rohr thread but I do know about where Whitworth threads are used
BP I understand what you are saying about issues with drainage systems on A/C Systems. After thinking about it for a while I'm inclined to believe that part of the issue being experienced with the naval vessels could have someting to do with not being able to effectively prevent condensate collected on the A/C coils from being blown back into the ship.
Over my years on the Great Lakes where there are always major issues with humidity too high in the summer & too low in the winter. I've run to many issues with condensate due to the differntial pressure across the coil to draw the condensate directly off A/C coils or out of the condensate catch pan under the coil and passed right back into the ship again, if the A/C system on full recirc, a clogged air filter or if for some reason condensate drainage system became ineffective due to the difference in air pressure or blockage. This is especially true, as it was on many of the "Canadian" built ships I was on, if the A/C coil is placed directly in the suction air duct very close to or coupled to the ventilation fan rather than a separate Air intake space designed to minimumize differntial pressure across the coil and more effective condensate drainage. Where space is a premium on a naval ship I would not be surprised if the system was setup with the A/C or chiller coils mounted in the fan suction air duct.
Troubleshooting 101 "Don't over think it - K.I.S.S. it"