23
PI-121
January 2020
5.13 Follow instructions for specific mode of operation:
CONSTANT PRESSURE and SHUT-IN MODE:
1. With all gun triggers squeezed to engage all guns in the system,
unit operator should build to about 1/4 of desired operating pres-
sure.
2. One operator at a time, and then both at the same time, should
disengage and engage their guns to ensure that the system pres-
sure remains near constant. There may be small differences due to
inexact flow characteristics between the fixed orifices and the gun
nozzles (Constant Pressure Mode).
3. Each operator should squeeze and release gun triggers two or
three times to ensure proper operation of gun and Multi-Mode
Valve. During this cycling, pressure should remain nearly constant.
4. Repeat steps 1, 2, and 3 at each of the following pressures without
exceeding the maximum operating pressure of the system:
• 1/2 of desired operating pressure
• 3/4 of desired operating pressure
• 2,500 psi below desired operating pressure
• Full operating pressure
Do not exceed maximum operating pressure of the lowest
rated component of the system. In Constant Pressure Mode, the possibil-
ity of variations in pressure at a specific flow between the gun nozzles
and the fixed orifice nozzle within the Multi-Mode Valve may require
either the gun(s) or the Multi-Mode Valve(s) fixed nozzle to operate below
the desired operating pressure. If this difference exceeds 2,000 psi or is
unacceptable for a particular application, resize or replace nozzles.
DUMP MODE:
1. Gun operator should squeeze triggers to engage control gun.
2. Pump operator should build system to 1/4 of desired operating
pressure.
3. Operator should squeeze and release gun triggers two or three
times to ensure proper operation of gun and Multi-Mode Valve.
Each time either gun trigger is released, system pressure should
drop to below 200 psi.