Abstract: Disclosed herein is an apparatus for filling gauge and sensor protectors with pressure transmitting fluid, diaphragm housing used therefor and method using such an apparatus. The apparatus includes tubing. A connector is connected to the inner end of the first side of the tubing. A syringe is filled with filling fluid and connected to the outer end of a first branch of the second side of the tubing. A vacuum pump is connected to the outer end of the second branch of the second side of the tubing. A fluid trap container is situated at a position of the tubing between both ends of the second branch of the second side of the tubing.

Abstract: A union joint structure, used for jointing a fluid feeding pipe to a target device, such as a fluid feeding tank, a fluid control valve, or a flow meter, is disclosed. This joint structure has a simple construction, and prevents leakage of fluid from the junction, and reduces the consumption of material. This joint structure also reduces its production cost, in addition to preferably reducing the space occupied by the joint structure. The joint structure has an enlarged-diameter end formed at an end of the pipe, an internal sleeve movably inserted into the enlarged-diameter end of the pipe, and a hollow locking bolt movably fitted over the pipe at a position around the enlarged-diameter end. The locking bolt has a head and external threads, and is stepped on its internal surface at a position around the junction of the head and the internal threads, thus having an annular step.