APPENDIX

Fig 50. Valve needle, yoke block, and lock nut ready for installation in fuel-valve body.

(3) Unscrew diaphragm cap and pull out washer, support, and valve-diaphragm assembly. To prevent loss of valve-needle adjustment(Fig 54), do not disturb position of yoke block by turning the needle.

Fig 51. Placing diaphragm assembly in position in fuel-valve body.

Fig 52. Installing parts in fuel-valve body.

(4) Slide the valve needle out of barrel; the yoke block and the lock nut may then be unscrewed from the valve needle, but adjustment (seedbelow) will be necessary when reinstalling.

c.Installation of barrel and valve-body assembly.

(1) To install valve needle, screw the yoke block and lock nut on the needle (Fig 50). Insert needle in valve body and barrel.

(2) Insert valve-diaphragm assembly into valve body (Fig 51), making sure that the yoke slips into the flat notches of yoke block.

Fig 53. Installing spring retainer in fuel-valve body.

(3) Slip the diaphragm support, washer, and cap over the yokeshaft. (Fig 52) Screw on the diaphragm cap by hand. Do not use a wrench. Install valve grip. (Par 74c)

(4) Place valve spring over end of needle and install spring retainer. (Fig 53) Apply wrench very lightly to tighten spring retainer.

(5) Adjust needle (seedbelow), and screw plug into the spring retainer.

(6) If hose has been removed, apply anti-seize compound lightly to the threads. Screw hose into fuel-valve body. Wrench should be applied very lightly to tighten.

d.Adjustment of valve needle. Needle is adjusted after installation of parts in barrel and valve assembly. Use care when resetting needle, as smooth operation of the weapon depends on accurate adjustment.

(1) Remove ignition shield (Par 18) and plug from gun.

(2) Use the valve-adjusting wrench (Fig 8) to hold the lock nut and apply a cabinet (narrow-bladed) screw driver (Fig 8) in the end of the needle. Turn needle until it makes a snug fit in the nozzle opening.

(3) Compress the valve lever and grip safety. The needle should draw back into the nozzle with the tip of the needle at the smallest diameter opening in the nozzle. (Fig 54)

(4) When the needle has been correctly adjusted, as in (3) above, tighten the lock nut with the valve-adjusting wrench, keeping the needle from turning with the screw driver. This will lock the adjustment. Screw plug into the spring retainer.

(5) Replace ignition shield. (Par 18)

e.Maintenance of barrel and valve body.

Fig 54. Valve-needle adjustment. Solid lines show needle in correct open position with point at smallest diameter of nozzle. Broken lines show needle in closed position.

(1)Damaged parts. Replace worn or damaged parts. If the diaphragm shows evidenceof tears or separation, or if leaks occur at the diaphragm, replace the valve-diaphragm assembly.

(2)Valve spring. If valve spring has lost resiliency, grasp it by the ends and stretch slightly, or replace.

(3)Nozzle leaks. If valve leaks at nozzle, and cleaning (Par 55d) does not remedy the leak, adjust needle (seedabove). If leak persists, either replace barrel and needle, or lap seat. To lap, place lapping compound on seat (in nozzle) and on needle point. Turn needle in seat until parts make a tight connection when seated. Remove lapping compound, reassemble, adjust needle, and test fire.

(4)Atomizer hole. If atomizer hole is clogged, clean with fine wire. (Par 52i)

a.Description and functioning. (Fig 55) The ignition head ignites the fuel when the flame thrower is fired. It is mounted on the fore part of the barrel. It consists of:

(1)Ignition-head body, which includes half of the front grip. Three set screws serve to tighten the ignition-head body to the barrel. The ignition-head body is made of aluminum.

(2)Trigger and trigger bearing, held between the ignition-head body and the coverplate by the trigger screw.

(3)Trigger rod, one end of which is held in the trigger bearing, the other extending through the ignition-head body. Pulling the trigger shoves the trigger rod forward, causing it to push a match in the ignition cylinder. The match ignites an incendiary charge in the ignition cylinder.

(4)Trigger spring, which hooks over a projection of the trigger and is held at its lower end by a screw, which is held in the ignition-head body. This spring pulls the trigger rod back from the firing position after the firer releases the trigger.

(5)Latch, located in the ignition-head body, in front of and above the trigger guard. The latch, set on a pin, engages the notch of the ignition shield, locking it in place. A latch spring holds latch in position.

(6)Coverplate, an aluminum casting which constitutes the left section of the front grip and covers the working parts seated in the ignition head body. The coverplate and body are held together by four screws and four lock washers.

(7)Spring case, which turns the ignition cylinder when the trigger is pulled.

(a) Four projections on the inner spring case are bent over the outer spring case to hold the two parts together.

(b) The inner-case pin (Fig 56) engages a stop on the inside of the ignition cylinder. The five projecting metal matches on the inside of the ignition cylinder are each in turn stopped by the lug on the forward-facing surface of the ignition-head body.

Fig 55. Ignition head disassembled, showing nomenclature and Chemical Warfare Service stock numbers for requisitioning spare parts.

When the trigger is pulled, the trigger rod pushes a match forward, causing an incendiary charge in the ignition cylinder to ignite. The spring in the case rotates the ignition cylinder until another match is stopped by the lug.

Fig 56. Parts of ignition head and ignition cylinder.

(c) The outer-case pin (on the outside surface of the outer spring case) fits into the notch in the ignition shield and holds the spring case as the shield is screwed into position. This action winds the spring in the case.

(d) A snap ring holds the spring case on the ignition-head body.

(8)Ignition shield, a cylindrical, thin-metal tube with a conical front end. The shield guides the flame and protects the firer. Eight holes around the base of the cone provide an air intake for burning the fuel. The base of the shield is threaded, and it screws onto the ignition-head body. A notch (Fig 56) in the base of the shield receives the latch and the outer-case pin of the spring case.

b.Removal of ignition head. To remove the ignition head, proceed as follows:

(1) Remove shield by lifting latch and unscrewing shield counterclockwise. (Fig 14) Keep hands and face away from front of barrel.

(2) If ignition cylinder has not been removed, remove it or allow it to fall off barrel.

(3) Pry off snap ring which holds spring case in position, using screw driver. (Fig 57) Be careful not to damage or break the ignition-head body by applying too much leverage.

(4) Remove the four screws and lock washers which hold ignition-head body and coverplate together. Lift off coverplate.

(5) Trigger, trigger spring, trigger rod, latch, and latch spring may be removed.

(6) Using a hex wrench, loosen set screws (Fig 58) and withdraw barrel from ignition head.

c.Installation of ignition head. To install ignition head, proceed as follows:

(1) Insert barrel in ignition-head body, pushing it as far forward as the shoulder on the barrel permits.

(2) Aline front grip and valve grip.

(3) Using hex wrench, tighten set screws on barrel enough to hold but not so tight that barrel is dented.

(4) Place latch, latch spring, trigger and bearing, trigger rod, and trigger spring in position.

(5) Put coverplate on ignition-head body and replace the four lock washers and screws.

(6) Slip spring case over barrel, and lock by forcing snap ring into the groove.

(7) When weapon is to be used on a mission, fit ignition cylinder and ignition shield in place on nozzle end of barrel as described in Paragraph18.

d.Maintenance of ignition head.

(1)Servicing. The ignition head should be cleaned and lubricated each time it is disassembled. (Par 49)

(2)Spring-case assembly. If outer case rotates and inner case does not, and no spring action occurs, spring is broken and spring case should be replaced as a unit. Do not disassemble or repair this part.

(3)Trigger rod and lug. When trigger is pulled all the way, end of trigger rod should extend 1/16 inch beyond lug on forward-facing surface of ignition-head body. If end of trigger rod is worn, replace rod. Lug on the ignition-head body should be approximately 7/32 inch high. If lug is worn or broken, replace ignition head body.

Fig 57. Prying snap ring from ignition head to remove spring case.

Fig 58. Loosening set screws with wrench so ignition head may be lifted off barrel.

The flame thrower is shipped and stored in a wooden packing case (Fig 59), which measures approximately 34 inches by 23 inches by 19 inches. Cubage of the case is approximately 8-1/2 cubic feet.

Fig 59. Opened packing chest showing flame thrower and other contents as received.

a.Storage procedure. After use and servicing (Pars55and56), if the weapon is not to be promptly reused on another mission, it should be returned to the packing case. Before disconnecting the gun group from the tank group and storing the weapon, the ignition cylinder should be removed, the fuel discharged, and the pressure released. Operate fuel valve to release any residual pressure in the fuel tanks. The deflector tube must be removed from the safety head (Fig 11) to permit the tank group to fit into the chest. The deflector tube should be kept in the spare partskit or tool kit until the next use of the weapon. The spare parts kit, the tool kit, the extra cans of cylinders, TM 3-376A, and the coupling plug (Fig 7) should remain in the chest except when they are being used. Wooden fittings hold the tank group in place, with the pressure tank up. The gun group is disconnected from the tank group and is kept with fuel hose connected to the gun on the gun mounting board in the chest. (Fig 10)

b.Rust prevention. If the flame thrower, parts, and tools are to be stored for a considerable length of time, especially in a damp climate, all exposed metal surfaces should be covered with a rust-preventive compound. Store in a dry place.

References pertaining to the care and use of flame throwers include:

AR 850-20Precautions in Handling GasolineAR 850-60Compressed Gas Cylinders; Safe Handling, Storing, Shipping, UsingFM 31-50Attack on a Fortified Position and Combat in TownsFM 100-5OperationsTM 3-220DecontaminationTM 9-850Cleaning, Preserving, Lubricating, and Welding Materials and Similar Items Issued by the Ordnance Department

Precautions in Handling Gasoline

Compressed Gas Cylinders; Safe Handling, Storing, Shipping, Using

Attack on a Fortified Position and Combat in Towns

Operations

Decontamination

Cleaning, Preserving, Lubricating, and Welding Materials and Similar Items Issued by the Ordnance Department

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