Graco Series D, 223177 Service, Pressure Relief Procedure, Piston and Intake Valve Adjustment

Service

Pressure Relief Procedure

WARNING

PRESSURIZED EQUIPMENT HAZARD

The system pressure must be manually relieved to prevent the system from starting or spraying acci- dentally. To reduce the risk of an injury from acci- dental spray from the gun, splashing fluid, or moving parts, follow the Pressure Relief Proce- dure whenever you:

Dare instructed to relieve the pressure,

Dstop spraying,

Dcheck or service any of the system equipment,

Dor install or clean the spray nozzle.

1.Shut off the air or hydraulic power supply to the pump.

2.Close the bleed-type master air valve (required in air-powered systems).

3.Hold a metal part of the gun firmly to the side of a grounded metal pail, and trigger the gun to relieve pressure.

4.Open the drain valve (required in your system), having a container ready to catch the drainage.

5.Leave the drain valve open until you are ready to spray again.

If you suspect that the spray nozzle or hose is com- pletely clogged, or that pressure has not been fully relieved after following the steps above, very slowly loosen the nozzle retaining ring or hose end coupling and relieve pressure gradually, then loosen completely. Now clear the nozzle or hose.

Piston and Intake Valve Adjustment

See Fig. 1. The fluid piston and intake check valves are factory-set for pumping medium viscosity fluids. The ball stop pin (18) in the intake valve is in the lowest set of holes. The piston ball travel is set at 0.204 in. (5.2 mm), measured from the end of the adjustable plunger rod (23) to the top of the ball (22). This distance represents four complete turns of the rod

(23)from the top of the ball.

4 307983

1.If you are pumping heavy viscosity fluid and erratic pump operation develops, disassemble the pump as explained on page 5. To increase the ball travel in the intake valve, move the pin (18) to the center or upper set of holes. To increase the ball travel in the piston valve, place the piston in a vise, loosen the upper cap (27) to relieve tension on the plunger rod (23), and turn the plunger rod counterclockwise two complete turns beyond its factory-set position, or enough to set the total ball travel to 0.306 in. (7.8 mm).

2.If you are pumping lighter viscosity fluid and surging develops, disassemble the pump as explained on page 5. To decrease the ball travel in the intake valve, place the pin (18) in the lowest set of holes. To decrease the ball travel in the piston valve, place the piston in a vise, loosen the upper cap (27) to relieve tension on the plunger rod (23), and turn the plunger rod clockwise two complete turns beyond its factory-set position, or enough to set the total ball travel to 0.102 in. (2.6 mm).

27

23

Ball Travel

22

Piston Valve

18

16

Ball Travel

15
	Intake Valve	06081
Fig. 1