Shurflow surge supressor

[quick-ls1]

Shurflow surge suppressor

I started to setup my Shurflow system this weekend and decided I really did not like the surging. The diaphragm pump seems to surge slightly no matter how high the rpms are.

I decided to experiment with a small intermediate tank to see if it would smooth things out. It turned out better than I imagined and the setup is really cheap and easy to assemble. I used a Cullagan Marine water filter enclosure that I got at Lowes for about $19.

See Pics here

The enclosure is completely plastic and is rated at 125psi (it feels like it will support way more than that for short periods of time and It held fine for me at over 220psi).

Anyway, the spray and pump are both very smooth now, the surging is completely gone, even at low RPMs and pressure. The new problem is finding a solenoid and pressure switch that can hold the incredible pressure this thing can produce. I ran it wide open and it hit 220 psi. My pressure switch started to leak all around the seams (I use this to trigger a LED on my pillar pod). After removing that, the solenoid body blew apart and an incredible stream of water hit my ceiling.

Anayway, I thought some of you guys might be interested in this.

 

[salvageV6]

I am, interesting information.

 

[Gokou]

Originally posted by quick-ls1 [/i]
The new problem is finding a solenoid and pressure switch that can hold the incredible pressure this thing can produce. I ran it wide open and it hit 220 psi. My pressure switch started to leak all around the seams (I use this to trigger a LED on my pillar pod). After removing that, the solenoid body blew apart and an incredible stream of water hit my ceiling.
[/QUOTE]

LOL! Sounds like me. I exploded my 2nd stage solenoid during my first test run of my system last weekend. Hit the test button... everything's OK for a second... BANG! And then a big puddle of water. Oops.

Anyways, here's a good solenoid for you:

http://www.valvestore.com/64sksova12vd6.html

Rated for 275 psi.

Parker makes some of their "gold ring" solenoids good for up to 750 psi. MSC Direct stocks them, about $50 for valve base and appropriate solenoid coil.

 

[Razor]

The more nozzles, selenoids, relays, wiring, accumulators, and stuff you have in your systems the more likely there is to be a problem...

The pulsing can be tamed down nicely by decreasing voltage to the pump... leave the regulator set at 100-125 psi and drop the pump voltage. It really puts a nice mist at lower voltages. You put 13 volts it will hit the limiter with force..its suppossed to..and then running that pump WOT drawing high current..will lead to premature diaphram failure/motor damage.

Good link on the selenoid for applications like HOT AIRS that need selenoids..

 

[quick-ls1]

I bypassed the regulator and lowered the voltage. It still surged slightly. I'm not talking about the major on off thing it does with the regulator. I'm talking about the natural surging/fluttering the diaphragm pump does as it makes each revolution.

The intermediate tank eliminates any visible fluttering/surging. The pump is pushing through a 3/8 union directly into the intermediate tank and then that tank has a 3/8 to 3/16 npt going out. The intermediate tank holds about 1pt, so you end up with a buffered regulator of sorts. It also acts as a gravity filter, since the liquid has to flow up to get out. It actually filtered out some pretty small stuff while I was testing it.

It’s not for everyone, but I think it is worth a try.

I ordered those solenoids and they should be here tomorrow

 

[salvageV6]

I had the same issues as you quick-ls1, you are not alone.

I like the intermediate tank/accumulator idea also.

Staging has worked well for me so I will try it again with this setup.

Hope the NOS solenoid(s) holds up.

I think they will since they seem to be all steel.

 

[Gokou]

Julio/others:

What are you using to reduce the voltage being fed to the pump?

A resistor bank would be a bad way to go because it would make the pump lazy. Are you using some sort of PWM controller?

Right now I'm running my pump with the switch bypassed at full voltage... I can hear that it's loaded quite hard. I intend on keeping the pressure switch bypassed, but I'd like to reduce the voltage being fed to the pump to reduce the pressure and load on the motor and pump.

Troy

 

[salvageV6]

What do you mean by resistors would make the pump lazy?

Slower running for sure, try .5 ohms in series 35 watt or better resistor.

I think in a 2 or 3 (or more) stage kit you would only need the resistor in the first stage.

Surging goes away with more nozzles in the loop.

 

[Razor]

Originally posted by Gokou
Julio/others:

What are you using to reduce the voltage being fed to the pump?

A resistor bank would be a bad way to go because it would make the pump lazy. Are you using some sort of PWM controller?

Right now I'm running my pump with the switch bypassed at full voltage... I can hear that it's loaded quite hard. I intend on keeping the pressure switch bypassed, but I'd like to reduce the voltage being fed to the pump to reduce the pressure and load on the motor and pump.

Troy

Troy..you with a TTA..should know..sig below

Look at the PAC description..to think your car comes with a factory 3 bar

The resistors on pump deal..yep..even tho there are others that will argue the point..see as the load on the pump increases(current) so does the voltage drop across the resistor..simple Ohms law I=E/R whereas I=current..E= voltage R=resistance. So as the pump pressure increases it sees less voltage..makes backwards sense but to reduce voltage to the pump in an okeee way..works.

Resistors dont regulate..they limit.. PWM is the way.. thats how they do it in industry..

 

[Gokou]

Originally posted by Razor
Troy..you with a TTA..should know..sig below

Look at the PAC description..to think your car comes with a factory 3 bar

The resistors on pump deal..yep..even tho there are others that will argue the point..see as the load on the pump increases(current) so does the voltage drop across the resistor..simple Ohms law I=E/R whereas I=current..E= voltage R=resistance. So as the pump pressure increases it sees less voltage..makes backwards sense but to reduce voltage to the pump in an okeee way..works.

Resistors dont regulate..they limit.. PWM is the way.. thats how they do it in industry..

Duh, I forgot about your website. And my water injection systems isn't on my TTA, it's on my Chevelle, but now I'm thinking about building another setup for my TTA. For my Chevelle I have a 2-stage setup with solenoid valves-- I don't really want progressive pump speed control, I'm only looking for a way to drop the voltage slightly to maintain a reasonable pressure and pump amperage draw. Julio, your setup is really cool and if this was on my TTA I would have one; but since this is on my Chevelle my needs are a little different.

Julio is exactly right on the reason resistors in line with a motor make them "lazy." The proper way to control speed on a DC motor is PWM, not using resistors. (Although low-frequency PWM is hard on the brushes and commutator in a brushed DC motor) The other way would be to use a DC-DC voltage converter to drop the voltage but also provide a steady voltage, whereas the resistors would provide a decreasing voltage with increasing load-- exactly what you don't want to do.

Troy

 

[Razor]

The SAC on my webby is just for that purpose For non progressive apps..

 

[salvageV6]

How do you get an increasing load on your first stage?

Once the pump is running, with no bypass, it's pretty much a static system, after all we are trying to eliminate pump surges not enable them.

Try a .5 ohm resistor.

Is the PWM system a speed controller or current limiter?

 

[Razor]

Originally posted by salvageV6
How do you get an increasing load on your first stage?

Once the pump is running, with no bypass, it's pretty much a static system, after all we are trying to eliminate pump surges not enable them.

Try a .5 ohm resistor.

Is the PWM system a speed controller or current limiter?

Speed controller by way of varying the signal to the pump...Where as you take a square wave and the amount of "on" time that the wave is "on"..will drive the pump harder. So when all the portions of the wave are "on" thats full output. When 1 percent of the wave is "on"..that would be least output. The progressive controller varies the "on" time the wave has in laymans terms. Frequency doesnt change.."on" time of wave changes. Thats the majic. WIth a voltmeter it appears like the voltage is increasing as the pump spins faster. Yet if you looked at with a scope, you would see the signal as 12 volts peak-to-peak, yet reads 1 volt dc on low. Actually lower since it will go down to .1 but pump wont spin on .1 Takes about a volt to get the shureflow spinning.

If you measure voltage to the pump with the resistor in line, if the load on the nozzle changes, so will voltage applied to the pump, cuase as load increases so does the voltage drop across the resistor and thus less applied to the pump. Not that it doesnt work, but its really a bandaid to drop the pumps output. One of those loads is the pressure within the intake tract..aka Boost.

I dont recommend running the Shureflow at WOT drawing in excess of 10 amps. Its not good for the motor and/or pump in the long run. Short blasts who knows..Better to have it bounce off its limiter at a higher pressure than damage the pump.

HTH

Kinda weird how it works..but it works

 

[salvageV6]

I think the overall dynamics are much simpler actually.

Thanks for the answer.

PWM is usually used to reduce heat in lieu of a resistive type controller and can over come the internal motor resistance, which should be quite low in the Shurflo anyway, and provide a bit more torque when running since the PWM is a 12 volt (supply) P-P device and not resistive limited voltage to the pump motor.

Second and third stages obviously, to me anyway, can run the pump WOT no controller of any type needed.

First stage with an M10 perhaps a PWM, or a resistor, or the accumulator/muffler tank would be the answer.

 

[quick-ls1]

quick update..

I did some more testing today with the new solenoid. It works great.

I put a 300psi gauge on the system and the pump could push it right to the 300psi max when running full out with an m10.

I also discovered that the solenoid needs its own isolated power source; don't try to run it off the pump supply (use a relay).

 

[Razor]

Yup it can push it to 300..problem is for how long ??? And I doubt you need 300..thats insane pressure

Good info tho..need someone with a 400 PSI guage to see if they can bury the needle..

 

[Gokou]

Originally posted by quick-ls1
quick update..

I put a 300psi gauge on the system and the pump could push it right to the 300psi max when running full out with an m10.

I also discovered that the solenoid needs its own isolated power source; don't try to run it off the pump supply (use a relay).

HOLY CRAP!

I guess I need to either step the voltage down to my pump or hook up the pressure switch again. I had no idea these pumps could push that much pressure! That's well beyond the ratings of my hoses and push-lock fittings.

Thanks for the info!