We are talking fluid dynamics. Air is a fluid where flow is concerned. I don't like it at all. I just can't come up with a better solution right now. Worst case scenario is that you will drive around for short periods with elevated fuel pressure. Other than that, no doubt it will work.

 

Agreed, and I don't have the education to be able to debate on this subject.

 

Or, a standard bleeding boost regulator system like they have on gassers, it uses a check valve desighn and has the air bleed you would need, that way, you don't get any forein air into your intake.

 

So the check valve has an air bleed in it? Or the check valve design is built into the regulator?

 

JT, I messed this thread completely. It happened when I was away on vacation.

Guys,

Unless I'm completely off base and wrong here you can simply install a check valve in the boost reference line. The boost will go through the check valve and as long as there is at least 1-2.5psi of boost on the line the check valve will stay open.

I'm looking at a Deltrol check valve (p/n CMM10B1) in the catalog here at work that looks like it would work. It's got 1/8" NPT threads and is a metal to metal seat for a leak tight seal for use with liquids. It requires 1-2.5psi to remain open.

Once the diaphragm blows the fuel pressure (at least 65psi, or whatever it is set for) wil shut the check valve...... It will always close on a diaphragm break due to the fuel pressure being higher than the boost pressure.....


Tell me what you guys think about that.


Now, here's one for Kwikkordead...... I'm also looking at an air bleed valve for use on hydraulic systems that bleeds off air until the system reaches 50psi. You simply mount it at the highest point of the system and plumb the outlet back to the tank.

Can you say poor man's air bleed?!?! It's also made by Deltrol, p/n AB20S, it's only available in 1/4"NPT. Only thing is it's made for use with hydraulic fluid. So the diesel might prematurely wear it out. I'll have to check with my supplier.


John

 

I didn't realize that the check valve would stay open with so little air pressure. That would most likely work in this application to let boost bleed back down. Do you have a website or a place I can see one of these things and check on the pricing?

 

I'll dig up the site tomorrow when I get back at work. Also, you could add a quick exhaust valve between the regulator and the check valve.

Not only would the quick exhaust valve insure that the pressure releases from the regulator once the boost drops down but it would also allow an outlet for the diesel should the diaphragm blow.....

If this confuses anyone I can draw it up....

 

yes, but how would you activate the dump valve once you wanted pressure to leave the line? would it just hang open with a certain amount of boost and create a leak?

i'll just stay with my hose i have now. the risk of a failing regulator is not great enough for me.

 

Yuppa the check valve WILL stay open as low as 1 to 2 psi in a forward flow condition. HOWEVER it WILL close on any sort of back flow, that is kinda what it is designed to do. Loose boost signal and the "apparent" pressure differential will be greater than 1 psi high side to low side thus closing the valve.

My $.02, Used to be a rocket scientist until we blew up the site. Your mileage may vary.

 

John7894 that little bleed valve sounds pretty neat!
I have the my bleed off oriface mounted on the high point as well.

 

Has anybody thought of a little solenoid operated valve? Could be just a teeny tiny one, wired to open when key on and shut when key off. Even if it failed, all you'd lose is your increased fuel pressure, since most fail closed. They've gotta make them, just gotta find one.

 

The quick exhaust valve is automatic. It opens on a pressure differential. Depending on which side has more pressure dictates if it opens or closes.

Just adding the check valve will solve the runaway problem should the diaphragm rupture. Also, the runaway will stop just by shutting off the truck too, but we all know what happens when you shut down a PSD while driving down the road!!!!! It ain't fun.

 

are regulator failures common enough to warrant this? if it's that big of a deal i will just go without a boost reference. i guess i dont see the big deal in having a fancy checkvalve or some electronic control in the middle.

 

If the boost reference helps with power and you decide to keep it I'd throw a check valve on there. The valve is only about as big as one of your fuel fittings. It's not big at all. I'm going to find the web link.

 

Here's the website link to the check valve. http://www.deltrolfluid.com/pdfin-line/in-line11.pdf


Here's the link to the air bleed. http://www.deltrolfluid.com/pdfin-line/in-line18.pdf


I do a little pneumatic system design here at work every now and then. I just never open the catalogs I have. I happened to be looking for something else the other day and came across the check and air bleed and thought about incorporating them into our fuel systems.