Valve Service Parts and Tools
Installing Valves in SCUBA Cylinders
Before installing the valve, any existing lubricant should be completely removed from threads and always place a new neck o-ring (an oxygen compatible neck o-ring is always included with our valves). Dive Gear Express currently does not recommend using any form of lubricant, even oxygen compatible lubricant, when installing our Nitrox Ready SCUBA valves in oxygen clean cylinders. For more information, please read Lubrication and SCUBA Valves.
The dip tube can be installed hand tight and snugged up with a hex key, about 40 inch-pounds, but do not over tighten or it will break off. The valve should be installed in the SCUBA cylinder with the least amount of force that will form a seal and retain the valve in place. Modern SCUBA valves that capture an o-ring in the cylinder neck can be installed by hand and snugged up with an open-end wrench across a flat at the base of the valve, about 50 foot-pounds. The threads should not bind and force is NOT required to fully screw the valve home. Do not use the wrench across the face of the valve, do not over tighten and do not bang on the handwheel. Take care to not over tighten the valve because it's the o-ring that makes the seal. An inspection should follow tightening the valve; be sure there is metal to metal contact all the around the base of the valve and the neck of the cylinder.
Should the modular port plug or bonnet nut need to be replaced, it also can be hand tight and snugged up with an open-end wrench, about 30 foot-pounds. Note that port plugs used on the modular valve with the typical side handwheel are notched on the corners of the wrench flats. The notches indicate the screw threads are reversed, and must be rotated clockwise to remove and rotated counter-clockwise to install. This is the opposite of typical screw threads and attempting to remove the notched plug using counter-clockwise force will permanently damage the valve.
New scuba valves always include a properly installed over pressure relief device (PRD aka "burst disk") safety assembly. If the safety assembly is ever removed from the valve, the disk and gasket must be discarded because reusing a disk will also cause it to rupture prematurely. Should a safety assembly ever need to be replaced, install it using a socket wrench at 100 to 120 inch-pounds. Note that an inch-pound calibrated torque wrench must be used in order to assure proper function of the pressure relief device; too little torque will result in a leak or too much will result in premature rupture.