Viking pump MAG DRIVE 855 SERIES, Technical & Service Manual

Page: 14 / 16

SECTION TSM 685.2 ISSUE C PAGE 14 OF 16
fIGURE 22
VALVE – AS, AK, AL, KE AND KKE SIzES
VALVE - LIST OF PARTS
1. Valve Cap 6. Valve Body
2. Adjusting Screw 7. Valve Spring
3. Lock Nut 8. Poppet
4. Spring Guide 9. Cap Gasket
5. Bonnet
DISASSEMBLY – RELIEf VALVE
Mark the valve and head before disassembly to insure proper
reassembly.
1. Remove the valve cap.
2. Measure and record the length of extension of the
adjusting screw. Refer to “A” on figure 22.
3. Loosen the locknut and back out the adjusting screw
until spring pressure is released.
4. Remove the bonnet, spring guide, spring and poppet
from the valve body. Clean and inspect all parts for wear
or damage and replace as necessary.
ASSEMBLY – RELIEf VALVE
Reverse the procedures outlined under DISASSEMBLY
– RELIEf VALVE. If the valve is removed for repairs, be sure
to replace in the original position. The relief valve adjusting
screw cap must always point towards the suction side of
the pump. If the pump rotation is reversed, remove the relief
valve and turn end for end. Refer to figure 3, page 3.
DANGER!
Before starting pump, be sure all drive equip-
ment guards are in place.
failure to properly mount guards may result in
serious injury or death.
PRESSURE ADJUSTMENT
If a new spring is installed or if the pressure setting of the
pressure relief valve is to be changed from that which the
factory has set, the following instructions must be carefully
followed.
1. Carefully remove the valve cap, which covers the
adjusting screw.
2. Loosen the locknut, which locks the adjusting screw so
pressure setting will not change during operation of
pump.
3. Install a pressure gauge in the discharge line for the
actual adjustment operation.
4. Turn the adjusting screw in to increase pressure and out
to decrease pressure.
5. With discharge line closed at a point beyond the pressure
gauge, gauge will show the maximum pressure valve will
allow while the pump is in operation.
IMPORTANT
When ordering parts for the pressure relief valve, always
give the model number and serial number of the pump as it
appears on nameplate and name of the part wanted. When
ordering springs, be sure to give pressure setting desired.
TABLE 8