36
PI-121
January 2020
Problem
Remedy
Constant Pressure
Mode: System
pressure drops
excessively when
gun triggers are
released, but no
water is exiting
through the gun
nozzle.
Fixed nozzle located in Multi-Mode Valve dump port
has become worn, blown out, or was sized too large
and does not match the flow rate of the gun nozzles, or
one or more gun nozzles have become fully or partially
plugged. Resize and/or replace nozzle(s) as needed.
Constant Pressure
Mode: System
pressure drops
excessively when
gun triggers are
squeezed, but no
water is escaping
through the dump
port and no water
leaks are present
anywhere in the
system.
One or more of the gun nozzles has become worn or
has blown out, or the nozzles were sized too large and
do not match the flow rate of the fixed orifice nozzle, or
the fixed nozzle has become fully or partially plugged.
Resize and/or replace nozzle(s) as needed.
Water is leaking
from one or more
of the weep holes
on the Multi-Mode
Valve body
1. One or more of the cartridge seals are leaking.
Remove cartridge and check condition of seals.
Replace seals or entire cartridge if necessary.
2. If replacing the cartridge does not solve the prob-
lem, it is possible that the valve body is cracked.
Contact a Jetstream technical support representa-
tive to arrange for verification and repair.
A waterjet cut
through the elbow
of the Multi-Mode
Valve dump port
while operating in
Constant Pressure
Mode
Diffuser has failed due to improper maintenance. Shut
down system immediately and replace diffuser and low
pressure elbow.
When operating in Constant Pressure
Mode, the diffuser must be replaced after every 200
hours of operation to prevent component failure, which
would result in waterblast operators being exposed to
a dangerous waterjet from the dump port.