Graco Inc 307-434, 216-119 manual Replacing Electrode Stem of Fluid Needle

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should be taken when starting threads. Applied

vide you with years of durability and efficiency

These working parts require periodic replacement:

1.Air cap (7).

2.Fluid tip (6).

3.Needle, fluid (41).

Removing Fluid Tip

To remove fluid tip (6) for cleaning or replacement, remove the ring nut (8) and air cap (71, turn off the atomizing air, trigger the gun to release needle pressure on the tip. Remove the tip with a wrench. Replace with the needle triggered to the rear.

When replacing air cap (7) on the gun, be sure the wire electrode coming from the needle (41) is centered in the

air cap center hole. The best method is to slide the air cap onto fluid housing (51, making sure that the wire

goes through center hole of air cap, then tighten ring nut (8), onto barrel (42) allowing air cap to be drawn up evenly on the fluid tip. Check alignment of ionizing wire in the fluid stream.

Removing Fluid Tip Housing

If the housing (5) is removed, the o-rings (2) should be replaced and the housing firmly seated. The housing must be torqued no more than 15-20 ft-lb (20 N-m), or plastic threads may become stripped. Lubricate with petroleum jelly new o-rings on housing before replacing in gun barrel.

NOTE: Fluid tip (6) must be removed from housing before replacing to avoid damage to ionizing wire.

Replacing Fluid Needle

Turn off the atomizing air and fluid, trigger the gun to release needle pressure on the tip. Remove ring nut (8) and air cap (7). Remove fluid tip (6) with a 7/16 in. wrench. Remove nut (19) and screw (31) from the rear of the gun. With a long nose pliers pull out needle ex- tension (46), nut (291, nut (301, spring (331, and needle (41). Unscrew needle (41) from extension (46). (Pliers maybe necessary as Loctite is used on threads.) Install new needle (411, applying Locrite no. 290 or equivalent to threads to prevent needle from coming loose during operation. Reassemble needle into back of gun using extreme care. Ionizing wire must remain straight as it passes through rear actuator packings (18).

After needle is assembled in the gun, replace fluid tip (6) and rear spring (33) and spring (341, along with ad- justing screw (311, locknut (19) and air cap (7). For ad- justment see Replacing Fluid Needle Extension.

Replacing Needle Guide

Needle guide (47) is pressed into rear of fluid housing

(5). Remove fluid housing and press out needle guide. When replacing be sure internal chamfered end faces rear of fluid housing.

Replacing Fluid Needle Extension

Remove needle (see Replacing Fluid Needle). When replacing extension (46); locknut (29) and needle ad- justing nut (30) must be readjusted on needle extension. Push needle (41), needle extension (46) and piston (38) fully forward, and turn the adjusting nut (30) all the way into the piston. Remove needle assembly from piston, turn adjusting nut two turns counterclockwise, and tighten locknut (29). This adjustment provides atom izing air just before the fluid needle is engaged and after seating.

Replacing Fluid Packing

The fluid packing (23) is replaced when the needle (41) is removed. Remove the packing nut (22) then pick out the packing and replace. Replace the packing nut. In- sert the fluid needle, tighten the packing nut and apply pressure on the packing to a firm seating. Do not over- tighten. The fluid needle should move without binding. When the gun is completely assembled and fluid pressure applied, the packing nut may be tightened to correct a slight leak.

Removing Gun Barrel

It is seldom necessary to remove the gun barrel (42) from the gun body (37). When necessary, this is ac- complished by unscrewing the gun coupling (8) and carefully lifting away from the gun body. Inspect o-rings (I and 4) and replace if necessary. To line up guide pin in barrel with hole actuator assembly keep indicator de- tent intop of barrel lined up with top of actuator.

Replacing Cylinder Adapter

The cylinder adapter (43) should not be removed unless damaged.

Replacing Electrode Stem of Fluid Needle

If electrode stem (48) of fluid needle (41) needs replace- ment, first unscrew electrode stem from fluid needle ex- tension (46). Unscrew setscrew, and remove old elec- trode stem.

Insert new electrode stem and replace setscrew. Reassemble fluid needle (41) to fluid needle extension Ma

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Contents Page R N I N G Never Immerse the Spray GUN in Solvent orOther Liquid T E R I a LTroubleshooting Chart WHAT’S Wrong Ged air holes or fluid tip. To remedy, clean the cap or tip307434 Replacing Electrode Stem of Fluid Needle Ref No Air Adjusting Screw Assy includes items / 26-26 Electrostatic Automatic AIR Spray GUNModel L46AIR CAP Consumption and Fluid TIP Flow Rate Chart Equivalence Chart OLD GUN NEW GUN307434 Dimensional Drawing Graco WarrantyElectrode KIT KIT, REPAIR, GUN FAN Valve