Graco 220-569 manual Reassembling the Displacement Pump, 
, Service

Service

Reassembling the Displacement Pump

NOTE: When thread sealant is specified, use low strength (blue) Loctite￿.

1.Place the two halves of the piston (16) around the packing (15*) and snap them together. See Fig. 10.

2.Apply thread sealant to the piston rod (17) threads. Screw the rod through the piston and packings and into the special piston nut (12). Torque the nut to 68–81 NSm (50–60 ft-lb).

3.With the lower pump housing (11) turned upside down, install the balls (5). Install the seats; place the vented seat (32) in the left side as viewed in Fig. 9 (housing has a label to identify the correct side), and the non-vented seat (6) in the right side. Install the gaskets (7*).

NOTE: The seats (6 and 32) are not reversible; the chamfered side must face the ball.

4.Place the intake housing (10) on the lower pump housing (11). Install the lockwashers (8) and capscrews (9). Torque to 34–40 NSm (25–30 ft-lb). See Fig. 10.

5.Place the intake housing (10) in a vise. Place one o-ring (2*) in each side of the lower pump housing (11) where the tubes (3) sit. Place anoth- er o-ring (2*) in the grooves at each end of the tubes. Place a gasket (18*) in both the upper and lower housings (1 and 11). Position the tubes and cylinder (4) in the lower housing (11).

6.Lubricate the inside of the cylinder (4). Slide the piston assembly into the cylinder.

7.Lubricate the throat packings and glands. Install them one at a time in the throat of the upper pump housing (1). Make sure the lips of the v- packings face down into the housing, and use a finger to seat the parts: the male gland (19{), one UHMWPE packing (20{), one leather packing (25{), UHMWPE, leather, UHMWPE, and the female gland (26{). Install the packing nut (21) finger-tight.

NOTE: Model 237–220 and 237–221 displacement pumps use 5 PTFE v-packings in the throat, instead of 3 UHMWPE (20) and 2 leather (25).

8.Install the upper pump housing (1). It may not seat well on the tubes and cylinder. Apply thread sea- lant to the threads of the three tie bolts (13). Install the bolts and lockwashers (14) from the lower pump housing (11). As you tighten the bolts into the upper housing (1), they will draw the housings firmly onto the tubes and cylinders. Tighten the bolts uniformly and torque to 34–40 NSm (25–30 ft-lb).

9.Torque the packing nut (21) to 68–74 NSm (50–55 ft-lb).

10.Place a ball (23), seat (24) and gasket (7*) in each side of the outlet housing (22). Install the outlet housing on the upper pump housing (1). Note that the flatter side of the housing faces the outside edge of the pump. Install the lockwashers (8) and screws (9), and torque to 34–40 NSm (25–30 ft-lb).

CAUTION

When installing the outlet adapters in the pump, be sure to hold the flats of both parts with wrenches. Overtightening the pump adapter into the outlet housing adapter may crack the housing.

11.Reconnect the displacement pump to the motor as explained on page 18.