pump check valves

I'm looking for recommendations on check valves from my pump set up.

I occasionally have problems with backwards flow from siphoning when i forget to close a valve. I see dudadiesel sells some, but they look like they would really reduce flow.

http://www.dudadiesel.com/search.php?query=check+valve

If you decide to go with a check valve, just make sure to find out what pressure the valve needs before it opens. For instance on the 809-HS models, the max pressure they make is only about 5psi and that's at dead head....so if you have a check valve that has a higher opening pressure, you will never get any flow through the system....

Thanks walter. I guess I'll stick with the ball valves for now.

A quick check of ball and swing checks shows a cracking pressure right around 4.5 psi. That's a no go.

I'm actually using a march AC-5B-MD, it could probably push that valve open, but I don't think I would have much in the way of flow.

If you have the "HS" models it would work...but with the resistance of the check valve in place, you would be limited to a flow of about 2gpm....
If you have the 815 pump or the upgraded impeller then your flow would be a hair over 5gpm...
These flows are not factoring in any physical head height you have in the system...its only the check valve...

With the series 5 you should be at about 13gpm....again not factoring the physical head height in the system...so if you had like 5' of head height the flow would be a hair over 10gpm...

Thanks Walter, like always you've been extremely help full.

On another note, I think I remember you posting
Ocean going boats were a hobby of yours. Do you restore or build boats? That's something thats always really interested me. But I don have the space for it now. The next house we buy is going have enough property for me to build a pole barn. Ocean kayaks are the biggest thing that I can make right now.

malador said:

Thanks Walter, like always you've been extremely help full.

On another note, I think I remember you posting
Ocean going boats were a hobby of yours. Do you restore or build boats? That's something thats always really interested me. But I don have the space for it now. The next house we buy is going have enough property for me to build a pole barn. Ocean kayaks are the biggest thing that I can make right now.

Click to expand...

It is my hobby...but im more in to the cigarette style boats. My first "big" boat was a 30' Scarab...the (Blue/yellow)
sold that and took a break for a few years while I worked on my house...currently building a 22' Chris Craft 222 Stinger...just did the paint/body work on it and now its time to put it all back together

WOW! Beautifull looking boat. I've probably never been in.a boat that's half as fast as your boat looks. Plus there are probably no fish blood stains in your boat
Thanks for sharing the pictures.

Lol...the blu/ylw boat topped out at around 78mph after I was done rebuilding the motors..they were 454's bored .030 over and by my guess were pushing around 450hp....nothing crazy by todays standards but it was sure fun And yes I have fished off that boat when we were down in the Keys for new years back in 2000
This white one i'm working on now will have a 383 Small block chevy that i'm hoping will hit near the 500hp mark when done

I contacted Duda Diesel about the cracking pressure of their check valves since I'm looking for some too.
They replied:
"Its too low for us to measure. I can blow them open with my lungs (1-3 psi)"

I would hope a 454 0.030 over would put out more than 450 hp! Unless those are two barrels hiding under the air filters

WalterAtMarchPump said:

...... pushing around 450hp....nothing crazy by todays standards ......

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Almost 15 liters of displacement in a 22' boat sounds nuts to me!

dstar26t said:

I contacted Duda Diesel about the cracking pressure of their check valves since I'm looking for some too.
They replied:
"Its too low for us to measure. I can blow them open with my lungs (1-3 psi)"

Click to expand...

if that's the case then with the slow speed 809 I would say it wont work as it max's out at 1.8psi. The HS models will crack them open no problem and with no head height it should give you around 4gpm....if you have around 4' of head height on top of that then your flow should be at about 2gpm (this is based on a 3psi cracking pressure for the valve)

jhoyda said:

I would hope a 454 0.030 over would put out more than 450 hp! Unless those are two barrels hiding under the air filters

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The stock 454's that were in there were only 330hp to begin with and the boat was a 1986 model.....I went mild on that one cause I wanted more reliability then anything else. During the 6yrs I had that boat all I ever did was change oil and spark plugs once a year and fill it with gas ! When I got into boating I was just getting out of jetskiing and we all had stupid modified machines that barely lasted the day without breaking down....but when your young and dumb, part of the fun is wrenching on your stuff but it gets tiring fast.
When I bought the boat used off a guy it had its issues and it too would most times need something done to it to make it through the day/weekend......and you quickly learn that girls don't know the difference between 35mph or 100mph on water.....but they sure as hell know the difference between running or not!!!

malador said:

Almost 15 liters of displacement in a 22' boat sounds nuts to me!

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it was actually a 30' boat that had the twins....the current 22'r has the single small block

I was just razzing you, I figured you had them loafing for reliability's sake.

jhoyda said:

I was just razzing you, I figured you had them loafing for reliability's sake.

Click to expand...

I figured