Section IX. MAINTENANCE OF PRESSURE TANKS

put gun head screw (29) thru gun handle (36) and screw gun head (31) down tight. d. Place gasket (28) into gun head (31). Screw fluid nozzle (27) into gun head (31) and tighten. Screw air nozzle assembly (28) onto gun head (31). e. Assemble fluid control assembly (20) by in- serting packing (23) into fan control body (22), turning fan control screw (24) two or three turns into fan control body (22), sliding three parts to- gether (22,23 & 24) over fan rod assembly (25) and screwing fan control needle (21) onto end of fan rod assembly (25). f. Insert fan control assembly (20) into gun han- dle (36) and tighten in place with fan control body (22). g. Assemble air valve assembly (12) by placing packing (14) into air valve body (15), screw packing nut (13) into air valve body (15), slide air valve stem (16) thru air valve body (15), packing (14) and pack- ing nut (13), slide air valve (17) over end of air valve stem (16), slide gasket (19) over air valve body (15), and place end of air valve spring (18) over air valve (17). TM 5-4940-228-14 h. Insert air valve assembly (12) into gun handle (36) and screw in place with air valve body (15). i. Position trigger assembly (11) over handle (36), insert trigger stud (10) thru trigger assembly (11) and gun handle (36) and screw in place with trigger screw (9). j. Place fluid control gasket (8) over end of fluid control housing (7) and screw fluid control housing (7) into gun handle (36). k. Insert needle assembly (3) into fluid control housing (7), place fluid control spring (2) over end of needle assembly (3) and screw in place with fluid control screw (1). l. Tighten packing nuts one quarter of a turn at a time. Actuate trigger after each adjustment. As soon as a binding or stiffness is felt, loosen packing nuts 1/8 turn. Adjustment is complete. m. Connect spray gun to the Paint Spray Outfit as described in Chapter 2. You can use water or paint thinner instead of paint for testing. Point spray gun into waste container while you spray. Check for an even spray pattern and look carefully for any leaks. Section IX. MAINTENANCE OF PRESSURE TANKS 4-18. General The pressure tanks are five gallon, dual regu- lated type, with air motor agitators. They are equipped with separate air and fluid regulators, gages and valves. The pressure tanks assure con- stant and uniform flow of fluid to the spray gun by automatically maintaining regulated air pressure. An air motor agitator provides means by which the fluid can be mixed inside each pressure tank, speed of mixing is controlled by a needle valve. 4-19. Operational Checkout. Use Figure 4-2 as a guide and proceed as follows: WARNING Before attempting any repairs, re- move all air pressure from the tank. An attempt to remove parts while tank is pressurized could cause those parts to be blown free and inflict in- jury. a. Visually inspect all parts of the pressure tank for damage, cracks or breaks. Replace damaged parts before proceeding. Check operation of all six clamps and screws (Refer to para 4-6). b. Loosen six clamp screws (55) and remove con- trol head assembly (1) from tank (52). Inspect gas- ket (49) carefully, replace if any signs of damage are observed. c. Remove insert pail (51) from tank (52) since it will not be needed while servicing. d. Place control head assembly (1) on tank (52) and clamp with six clamp screws (55) (hand tighten, do not use wrenches). e. Prepare the pressure tank for operational check out as follows: (1) Finger tighten needle valve (14) on air motor (15). (2) Unscrew (counterclockwise) both air regu- lator handles all the way out, then screw in five turns. (3) Close both shut off cocks (23 and 24). (4) Push slide valve (35) towards fluid pres- sure air regulator (33). (5) Apply air pressure of 60 to 80 psi to the air inlet connection (7). 4-5