The tank group stores fuel and pressure. The fuel is placed under pressure when the pressure-tank valve is opened. The tank group is supported upon the firer’s back and shoulders by the carrier.
66. PRESSURE TANK AND VALVE ASSEMBLY.
a. Description and functioning. The pressure tank and valve assembly ([Fig 33]) includes:
(1) Pressure tank. The pressure tank is a lightweight, airplane-type cylinder, able to withstand the great pressure which it contains. The tank is charged with air or nitrogen at 1,700 to 2,100 pounds per square inch pressure by use of auxiliary equipment as described in Paragraphs [31] and [32]. This pressure stays in the pressure tank until the weapon is ready to be fired. Opening of the pressure-tank valve releases air or nitrogen through the pressure regulator to the fuel tanks. Oxygen or combustible gases are never used in the tank because a violent explosion may result. The tank is large in capacity to assure ample pressure, and hence full range, for the entire load of fuel. The pressure-tank clamp ([Fig 39]), a steel-strap device with hinge and toggle-type latch, holds the pressure tank in place on the fuel tanks.
(2) Pressure-tank valve. (Figs [33] and [34]) This valve is screwed into the bottom of the pressure tank. The valve stem slides into the valve end of the valve flexible shaft. When opened by means of the valve handle and valve flexible shaft, the valve permits passage of compressed air or nitrogen through tubes and the pressure regulator to the fuel tanks. The valve is of the quick-opening, packless, diaphragm type.
(3) Pressure-valve handle and valve flexible shaft. (Figs [33] and [34]) The pressure-valve handle is held by a small nut on the end of the valve flexible shaft, which in turn is connected to the pressure-tank valve by means of the valve stem and a large hex nut. The handle and shaft extend to the right of the tank group, enabling the firer to open and close the valve without assistance when carrying the weapon. The handle slips over the end of the shaft and is held to it by a nut. The shaft is held to one of the fuel tanks by a clamp, nut, and bolt welded to the tank.
(4) Check valve. (Figs [33] through [35]) The check valve has the same function as the valve on a vehicular tire tube, but it is much heavier in construction and different in design because the pressure in the flame thrower is 50 times greater than that in an automobile tire tube. Connected by threads to the pressure valve, the check valve permits compressed air or nitrogen to enter the pressure tank during charging (Pars [31] and [32]) but prevents its escape when the outside source of pressure is removed. The cap is removed from the check valve only for charging or testing.
b. Removal. ([Fig 33]) To prevent damage to threads, leaks, and loss of pressure and range, remove pressure tank and valve assembly only when necessary.