Brennan Industries Inc. has introduced a new line of gap gages. The gages are designed to assure that instrumentation tube fittings have been sufficiently pulled up. The gages can be useful for tightening fittings in hard-to-reach locations. They are also suited for systems where insufficient make-up could result in dangerous or expensive consequences.
After installation of an instrumentation tube fitting and prior to pressurization of the system, the gap gage is inserted between the fitting nut and the body hex. If the gage will not fit in at any point of the gap, the nut has been properly made up, and no additional tightening is necessary. If the gage can be placed in between the fitting nut and body hex, the assembly procedure must be repeated.
Brennan gap gages have both "Go" and "No Go" ends and should only be used in initial make-up situations. They are not intended for use in remake assemblies. The new NGG Series carbon steel gages are available from stock in 5/8-inch through 2-inch sizes.