Giant Industries, Inc.
900 N. Westwood Ave.
Toledo, Ohio 43607
PHONE (419) 531-4600
FAX (419) 531-6836
www.giantpumps.com
© Copyright 2017 Giant Industries, Inc.
08/19 22947-50.indd
Operation
The whole discharge must be guided through the valve. Should the actual operating pressure exceed the adjusted operating pressure, the valve then
acts as a pressure regulator. The valve switches to pressure-free bypass operation when the spray gun shuts off and the spray pressure between
gun and valve remains idle.
The valve can be operated together with several spray guns. It is also possible to connect several pumps to one common discharge line.
IMPORTANT!
Valves are NOT SET when delivered. They become a SAFETY COMPONENT only after adjustment on the machine by trained
personnel.
Service and Adjustment
Re-servicing and adjusting work is only to be carried out by skilled tradesmen.
Safety Instructions
Observe direction of flow. The bypass must under no circumstances be closed or fitted with any shut-off device.
Continuous bypass operatoin without releasing the water can cause the liquid to heat up which in turn could damage the unit and
endanger persons.
Possible preventive measures:
1.) Limit the bypass duration (max. temperature 140 °F/60 °C); the duration is to be calculated by the operator and in conjunction with the operating
conditions.
2.) Use fittings (e.g. thermal valve on water inlet) to avoid heat increase.
To Adjust Pressure
1.) Open valve so that it is completely tension-free, i. e. loosen nut (24) and adjusting nut (23) so that the piston rod can be moved by hand.
2.) Spring pack is tensioned by adjusting nut (23) while the pump is running and with open gun (if more than one gun is used, all have to be open)
until required operating pressure is attained and no more water runs out on the bypass side. Then lock nut (24) to adjusting nut (23). If the nozzle
hole corresponds exactly to the flow-rate and pressure of the pump, no more water will run out over the bypass after the required pressure has
been attained.
If the nozzle hole is too small and the whole output won’t go through the nozzle after the max. pump pressure has been reached, on no account is
the valve to be adjusted higher than the max. operating pressure of the pump. In this case, the bypass should be partially left open. It is however,
advisable to install suitable nozzles.
To Renew Piston Rod Seals and Sleeves
Unscrew nuts (24+23). Remove spring pack (22). With a 6mm allen wrench, unscrew the 4 inner hexagon screws (20A) and remove spring support
(20). Remove woodruff key (19C) and remove inlet tensioning plug (2). Remove spring (4A), ball (5) and spacer disc (5A). Push out piston rod (18)
downwards together with inner parts (8, and 9). Remove piston body (15) with a size 19 wrench and pull piston rod out of guide case (10). Cut out
worn seals and replace. Then carefully clip O-ring (19A) and support rings (19B) onto the piston rod. Note order of installation. For 22948, 22949 and
22950, put packing (17) on piston rod (18). For 22947, put o-ring (17) and support ring (17A) on piston rod (18). Re-install guide sleeve (10) and
spacer (16). Check casing (1) surfaces and inner parts for dirt or damage as this will cause the seals to wear out quickly. Check O-rings (11&14) and
support rings (12) and replace as necessary. Remount piston body to piston rod with Loctite 648. Re-assemble in reverse order. Grease all parts
lightly with Silicone before reinstalling.
To Check and Replace Valves
Remove the plugs (2) and check whether the balls (5) or valve plate (6) are worn out. Remove valve seats (8, 7) with clipring pliers and check surfaces
for damage. Check O-rings (11) and replace as necessary.
22947(H), 22948(H), 22949(H), 22950(H) Operation and Maintenance
Troubleshooting Guide
Problem
Cause
Remedy
Valve switched
repeatedly when gun
is closed
Leaky Gun
Repair gun
Leaky pressure pipe
Seal pressure pipe
Leaky sleeve
Replace o-rings
Worn out kick-back valve body
Replace kick-back valve body or
o-ring or examine valve seat
Leaky seal (12,14)
Renew seal
Leaky piston rod
Defective o-ring/support ring
Replace piston rod seals and ex-
amine surfaces in guide plug
Leaky bypass at
nominal pressure
nozzle too small, too much water
Install larger nozzle
Worn out bypass valve
Examine and renew as necessary,
ball (5) and bypass valve body (8)
Pressure Guage
shows high pressure
peaks when shutting
off gun
Valve set too high above operating
pressure
Turn back adjusting nut (23) and
hexagon nut (24) or handwheel
Dirty valve
Clean valve (remmoving lime
deposits, etc.) Grease parts before
reinstalling