_d. Testing for leaks in pressure system._ After charging and * * * to test pressure. (Fig. 32.) To install gage, unscrew check-valve cap, =moisten end of check valve with water or saliva=, and screw gage in check-valve body. =Use of water or saliva as lubricant prevents cutting of the rubber washer by the check valve.= If pressure has * * * and then retested. =66. PRESSURE TANK AND VALVE ASSEMBLY.= _a. Description and functioning._ The pressure tank * * * assembly (Fig. 33) includes: (1) _Pressure tank._ The pressure tank * * * the fuel tanks. =The pressure-tank clamp may be adjusted to different outside diameters of pressure tanks by means of a nut and screw tightening device (fig. 35.1) or by means of a stepped ring at end of clamp.= [Illustration: FIGURE 35.1. (Added.) Adjustable pressure tank clamp, showing use of nut and screw tightening device.] * * * * * _b. Removal._ (Fig. 33.) * * * * * (2) _Removal procedure._ * * * * * (_h_) (Added). To remove check valve, unscrew check valve cap and check valve body, using wrenches. _c. Installation._ (Figs. 33 and 39.) * * * * * (7) (Added). To install check valve, apply thread compound lightly to threads of cheek valve body and screw into opening in pressure-tank valve. Tighten check valve body in position, using wrench. Screw check valve cap on check valve body and tighten with wrench. * * * * * =66.1 DETACHABLE PRESSURE TANK AND VALVE ASSEMBLIES= (Added). Newly developed detachable pressure tank and valve assemblies provide an improved and speedier method of servicing M2-2 portable flame throwers in forward combat zones. _a. Description and functioning._ (1) Detachable pressure tank and valve assemblies (figs. 35.2 and 35.3) are used in modified flame throwers. They make it unnecessary to replace empty complete tank groups with filled and charged complete tank groups. (2) Replacement of complete tank group, however, may be preferred when an extra supply of tank groups is available, or if thickened fuel is too stringy and viscous to pour. (3) Detachable pressure tank and valve assemblies can be attached only to flame throwers which include sockets (figs. 35.2 and 35.3) and shortened regulator tubes. Flame throwers produced recently include this design modification. (4) A plug and cap (fig. 35.3) on detachable pressure tank and valve assembly replace tube elbow (fig. 33) used on nondetachable pressure tank and valve assembly. _b. Removal._ Care must be taken to prevent damage to connections during removal and installation. The procedure for removal of pressure tank and valve assembly is as follows: (1) Close pressure-tank valve. Press valve lever and safety grip on gun to release all pressure from fuel system and gun.