If you want to slowly ramp the pressure to a system so it’s components don’t slam
into position when you apply that initial pressure, then a Soft Start valve is exactly
what you need.
You just insert one in line with your other FRL components and when you apply voltage
the soft start valve slowly pressurizes the downstream system until it gets to about 50%
of system pressure then it releases the full system pressure to the downstream portion
of the system.
The beauty of that is it slowly pressurizes your system so the equipment doesn’t slam
into position and break something, or even possibly injure someone.
Which means you’re saving wear and tear on your equipment, AND improving safety.
Another nice feature of these soft start valves is they isolate and dump the downstream pressure
to the atmosphere when they are turned off.
That’s really cool, because if you’re already using the soft start to ramp the downstream
pressure you can now isolate and depressurize the downstream system electronically without
adding any additional components.
You could even make this part of your ESTOP system to automatically depressurize when
the ESTOP button is pressed!
Awesome.
Be sure to add a muffler to quietly and safely disperse the pressure release.
If you don’t want to release system pressure when the valve is turned off, then just plug
the hole.
Could you use an adjustable flow control valve to do this?
Sure – it would definitely ramp the pressure on start up, BUT, it would also continue to
ramp pressure at all times making your system appear sluggish.
The Soft Start valve only limits that initial inrush – after the initial pressurization
the soft start valve becomes transparent and your system operates as if it wasn’t even
there.
And that’s the beauty of Soft Start Valves – they ramp the initial system pressure,
then they get out of the way so your system can operate normally.
Let’s do a couple examples.
Here I have the system pressure set to 100psi and the soft start valve is off so there is
no downstream pressure.
When I apply voltage to the Soft Start valve, the pressure at the output slowly ramps up
until it gets to about 50% of system pressure, and then it releases all 100 psi to the down
stream components – after they’ve had a chance to slowly - and safely - move into
position.
When I remove voltage to the valve, the downstream pressure is dumped to the atmosphere through
this muffler I have installed here.
Let’s do that again, but this time let’s set the system pressure to 40 psi.
We expect that when I apply voltage to the valve, the pressure should rise to about 50%,
which in this example will be 20 psi, then it should release the full 40 psi system pressure
to the down stream components, here we go.
Sure enough the pressure climbs to about 20 psi and then releases.
Perfect.
This valve is designed to slip right in line with the other modular FRL components, or
you can screw in a fitting and insert it anywhere you want in your system.
There are a couple key things you need to know to get these to work correctly.
First, you have to have down stream components – remember – this valve ramps the downstream
pressure until it reaches 50% of the system pressure.
If you have this open to atmosphere with no back pressure, then there will never be any
pressure build up and the valve will never open.
Second, you need to apply voltage to enable the valve electronically – these are available
with both 24 volt dc and 120 volt ac solenoids.
You can also enable the valve manually by pressing this red button.
Or if you push and twist, you can lock it in the on position.
Keep in mind you need the usual minimum air pressure for it to actuate AND the same downstream
rules apply - this valve needs to see that downstream back pressure to operate – even
if you operate it manually.
You can’t set the trip point – it will always trip at about 50% of system pressure.
It’s not exact, but very close to 50%.
You CAN set the ramp time.
Again, it is a crude adjustment and it is not linear, but there is a needle valve you
can adjust with an Allen wrench.
All the way IN will turn the valve off.
The more you screw the adjustment out, the faster the ramp time gets.
If you screw it all the way out until it hits the stop, the valve will ramp to system pressure
pretty much immediately.
Make sure you install it in the right direction.
It’s not real obvious, but there is a little arrow right here that shows the airflow direction.
There are a lot of pneumatic components on the AutomationDirect website.
You’ll find these under Pneumatics Components, Pneumatic Air Preparation, Soft Start Valve.
Select the size fitting you need and you’ll immediately have just the valves you need
to see for the different operating voltages and system component size – looks like this
one has options for the 22 series and the 32 series FRL components.
Soft Start Valves are easy to use and a great way to safely and inexpensively you’re your
initial system pressure.
Click here to learn more about soft start valves.
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