Proper Way To Set Unloader Valve
- Thread starter DirtBiker
- Start date
Grant
Administrator
PRESSURE ADJUSTMENT: Setting and adjusting the unloader
pressure must be done with the system “on”. Start the system with
the unloader backed off to the lowest pressure setting. Squeeze
the trigger and read the pressure on the gauge at the pump. If more
pressure is desired, release the trigger, turn adjusting nut one quarter
turn, squeeze the trigger and read the pressure. Repeat this process
until desired pressure is attained. Pressure fluctuation from
this established system pressure is minimal with the opening of
each additional gun.
Monitor the by-pass flow at each adjustment. If the by-pass flow,
with all guns or valves open, drops below 5% of rated unloader flow,
STOP ADJUSTMENT. The nozzle(s) selection is improperly sized
to achieve the desired system pressure.
Proceed by accepting the attained pressure OR selecting a smaller
or fewer nozzles OR increasing the pump RPM providing you
stay within specifications OR selecting a larger pump or dual pumps.
Once the desired system pressure is reached, stop adjusting and
set the top locking nut to hold the system pressure. Do not read the
pressure at the gun or nozzle for setting system pressure.
Check the nozzle(s) as part of regular maintenance and replace if
worn. Do not adjust unloader pressure setting to compensate
for worn nozzle.
pressure must be done with the system “on”. Start the system with
the unloader backed off to the lowest pressure setting. Squeeze
the trigger and read the pressure on the gauge at the pump. If more
pressure is desired, release the trigger, turn adjusting nut one quarter
turn, squeeze the trigger and read the pressure. Repeat this process
until desired pressure is attained. Pressure fluctuation from
this established system pressure is minimal with the opening of
each additional gun.
Monitor the by-pass flow at each adjustment. If the by-pass flow,
with all guns or valves open, drops below 5% of rated unloader flow,
STOP ADJUSTMENT. The nozzle(s) selection is improperly sized
to achieve the desired system pressure.
Proceed by accepting the attained pressure OR selecting a smaller
or fewer nozzles OR increasing the pump RPM providing you
stay within specifications OR selecting a larger pump or dual pumps.
Once the desired system pressure is reached, stop adjusting and
set the top locking nut to hold the system pressure. Do not read the
pressure at the gun or nozzle for setting system pressure.
Check the nozzle(s) as part of regular maintenance and replace if
worn. Do not adjust unloader pressure setting to compensate
for worn nozzle.
Russ Johnson
Equipment Expert
That is the proper way to adjust a flow controlled unloader. For a pressure actuated unloader, squeeze the gun and adjust the valve in until operating pressure is reached. Release trigger and watch spike pressure. It should be about 10% more than operating pressure.
Great Info Grant
Sirocco Jerry
Active member
Adjusting an unloader valve
...absolutely !!
..and for more detail..
click here.. Adjusting an unloader valve<o
>
Pressure gauge should be at the unloader outlet,
but if you have 2.. get one on your Hose reel..
you might be shocked at what it tells you.<o</o</o
...absolutely !!
..and for more detail..
click here.. Adjusting an unloader valve<o
>Pressure gauge should be at the unloader outlet,
but if you have 2.. get one on your Hose reel..
you might be shocked at what it tells you.<o
</o</o
Last edited:
gear junkie
New member
How do you tell the difference between a flow and pressure unloader? Either of them better? I never see a pressure spike when pulling the trigger...goes up slow....takes about 4 seconds to reach pressure. What kind of unloader is this?
"Red"
Graphic Designer
This is how I have mine set up (ignore the gauge on the right, it was defective). The gauge on the left is attached to a hose.
Sirocco Jerry
Active member
pressure coming up slowly..
is a "flow actuated" unloader.
Pressure actuated unloaders "trap" a spike pressure of more than working pressure after the unloader,
and that pressure "gushes" out when you pull the trigger gun.
gear junkie
New member
Thanks Jerry, What's the advantage to a pressure unloader?
Sirocco Jerry
Active member
Pressure actuated unloaders are this.. very specifically,
.. by request of every dealer they have in the world..
..cheaper.. SImple as that.
I have HOUNDED AR, Comet, Giant, Suttner, and MTM.. to build one..
We NEED a 4000 psi Flow-Actuated unloader that does NOT cost $500.
A K-7 unloader is flow actuated, but doesn't like doing over 3500psi.. they were designed for 3000.
the K-5 unloader is 3000 psi max, and not rebuildable (affordably).
The Giant version for 4000 psi.. is only good for 4gpm.. that doesn't count fore much.
Pressure Actuated unloaders are especially helpfull in multi-wand systems.
..you can divide flow easily, due to the regulating function of the valve.
otherwise..
Pressure Actuated unloaders are less expensive to build.
.. by request of every dealer they have in the world..
..cheaper.. SImple as that.
I have HOUNDED AR, Comet, Giant, Suttner, and MTM.. to build one..
We NEED a 4000 psi Flow-Actuated unloader that does NOT cost $500.
A K-7 unloader is flow actuated, but doesn't like doing over 3500psi.. they were designed for 3000.
the K-5 unloader is 3000 psi max, and not rebuildable (affordably).
The Giant version for 4000 psi.. is only good for 4gpm.. that doesn't count fore much.
Pressure Actuated unloaders are especially helpfull in multi-wand systems.
..you can divide flow easily, due to the regulating function of the valve.
otherwise..
Pressure Actuated unloaders are less expensive to build.
nibbsy
New member
Hi Jerry,
Have you looked that these VB 80/280 Zero – Flow sensitive unloader valve
They also have a smaller brother
http://www.sadit.co.il/Up/technical_specifications/5614015.pdf
I will have been running one beyond spec successfully for the last 18 months 4300psi at 8glm
Have you looked that these VB 80/280 Zero – Flow sensitive unloader valve
They also have a smaller brother
http://www.sadit.co.il/Up/technical_specifications/5614015.pdf
I will have been running one beyond spec successfully for the last 18 months 4300psi at 8glm
tomtucson
New member
Greg Queensland mentioned the Pulsar http://www.sadit.co.il/Up/technical_specifications/5614015.pdf which I had only seen in 8 gpm. Cat has this http://www.catpumps.com/products/pdfs/992413A_SST_7450_FlowSenseUnloader.pdf which looks the same actually. E-spec has the quantum z which is one of those if I am not mistaken. These flow unloaders with spring adjust - are they better?
Jerry Please Fix that Link