check valve warning

[ridiculously_necessary]

i purchased some 3/8" cv's on ebay. found out after 300 miles that they only hold 30psi. i was very fortuante that it failed after i hooked up the veg line instead of it hanginig loose like it was.

one seller, possibly all, dont advertise the psi limit. i had to track down the valve on aother site to find this information. its advertise for use with gas, diesel, and biodeisel.



anyway, wanted to shout out a heads up for those who may run across it. if your running a lower pressure lift pump type vehicle, cummins or dmax then i would imagine they would be fine.

ill update when i select a different valve. likely overkill.

[simone0414]

I got my 1/8" stainless check valves for the D2 lines from Leon. 30k miles on them & working good. My 3/8" check valve I got from Mcmaster Car. SkyskiJason suggest it( it's what he is using) & has about 20k miles on it. Also working well. Only possible downfall is it is brass.

This is the what I used from Mcmaster McMaster-Carr 7768k63.

[STROKED_NY_023]

Check these out bud...

Stainless Steel In-Line Check Valve 1/2" SS 316, NEW - eBay (item 120623425302 end time Apr-17-11 00:49:24 PDT)

These should work nicely. I just picked up 4 of them, they are similar to the CV's i use every day when i am working on well pumps. They will do well over 100 psi and they are NPT so you should be able to adapt your fuel lines easily to them.

[Aaron Berk]

Hey Stroked_NY

I've got those on my set up. I've got maybe 1hr on them so far. They dribble back just a little.

I have mine mounted into a 1/2" pipe tee, they are horizontally opposed. I did this so that they would push against each other and hopefully help keep them seated.

When I first energized/pressurized my system I had my d2 side unhooked. I could watch the drips coming out of the inlet side of one of the check valves.


It wasn't much, but it was consistent.




Thanks for keeping us up to date Matt!

[STROKED_NY_023]

Hmm interesting, like i said i use this style of check every day and haven't had any issues. Although i don't use them on diesel!!!!

[Aaron Berk]

Yeah I was surprised that they leaked, the fit and finish of them look robust enough.

Maybe there is a wear in period?

[STROKED_NY_023]

Not sure about a where in period. The ones I use hold very well... I will have to watch that when i do my conversion.

[ridiculously_necessary]

i order the high pressure compact ball CV on the bottom of this page, carbon steel, ill let you know what i find.

McMaster-Carr

[Fordnut74]

Just food for thought here. DO NOT put check valves directly on the inlet ports of an otherwise deadheaded engine. The 7.3's create a large pressure spike on startup that can easily exceed 500psi if there is nowhere for the pressure to go!! That is why the OEM valves are not true check valves. You need to have some Hose, or distance in the system somewhere to act as an accumulator or you will constantly have problems with check valves.

[Aaron Berk]

Matt, those look nice. I like that they mention the "bubble tight" seal. It sounds reassuring.

And Fordnut, your right
I talked with Shane at Rover Hybrids and he told me a pretty good story about troubleshooting over the phone with a guy who had check valve siphoning issues. The initial spikes from the split shots were messing with the CV's so bad that it would hold them open long enough to create a suction, and then the truck would be burning fuel from both tanks simultaneously.