New gas-powered water pump: siphoning

[ny_grass]

Yesterday I bought a 150 gallon/minute 2" Pacer water transfer pump for pushing water from my brook to the back of my property. I used the pump at noon today to fill up my 300 gallon stock tank; when I went back about 6pm the tank was empty. I didn't think anything of it (it has been VERY hot) and filled it up again.

However, given the luck I've been having, it occurs to me whether the water might be siphoning back out of the trough which is about 20' higher than the pump (of course, I leave the end of the pipe in the trough). I'd not think that pumps would be designed like this (they must have a 1 way valve that prevents water from flowing back out), but ... I guess I'm a little paranoid that I'm thinking I'm watering the animals but might not be ;-(.

Thanks to anyone who can confirm that there is no problem.

JR

 

[jedstivers]

It should have a rubber flap that keeps it from back siphoing. If it doesn't then it's defective.

 

[ny_grass]

It should have a rubber flap that keeps it from back siphoing. If it doesn't then it's defective.

Okay, that's good to know. It "shouldn't" be back siphoning. I guess I'm going to do some testing tomorrow ;-)

 

[High Cotton]

What about if you put a ball valve behind the pump as close to the water source as possible. That would kill 2 birds with one stone. You won't siphon back and also it won't take so long to prime the pump.

 

[Anonymous]

That's a positive displacement pump. If you put a ball valve on it make sure you shut the pump off before closing the valve. Otherwise you'll blow up the housing. Best bet would be a one way check valve on the outflow side

 

[ny_grass]

Checked on it twice today; both times there was water in the tank; seems that everything is fine and my pump is not back siphoning. Thanks.

 

[hillbillycwo]

I would still place a check valve on the output side of the pump and place one close to the tank. That way you are sure that the pump doesn't siphon and that you have no leaks in the water line that could cause a siphon to occur from the tank.

 

[1982vett]

Or just raise the discharge hose higher than the tank....

 

[bbirder]

Put a ball valve on the discharge side of the pump and shut it off right after killing pump. This will prevent siphoning. And, this is not a positive displacement pump. It is a centrifugal pump. A positive displacement pump is used for hi-pressure applications.
Don't forget to open it when you start the pump. Not the best situation!

 

[Anonymous]

They have an impellar, wouldn't that make it positive displacement. Not to argue semantics, just for my own knowledge

 

[lavacarancher]

Don't believe that pump is a positive displacement pump. It has an impeller.

I think you mentioned you were pumping water from a stream? Perhaps something got stuck in the flapper holding it open allowing the water to drain out of your tank. Just a thought.

 

[bbirder]

You are correct. Centrifugal pumps have impellers and are not positive displacement. PD pumps are usually piston pumps, hence positive displacement. Also most centrifugal pumps do not have flapper valves. Diaphragm pumps have flapper valves.

 

[Anonymous]

I stand corrected yet again.

 

[moodacow]

Checked on it twice today; both times there was water in the tank; seems that everything is fine and my pump is not back siphoning. Thanks.

Where did the water go the first time?

 

[bear]

Pacer, Wacker and a few other comparably constructed pumps do have the flapper on the suction side of the pump, however they are not always 100% effective. As has been suggested, you may want to install a ball valve to prevent drain back. Other options would include a foot valve on your suction hose or an inline check valve on either the suction or the discharge hose.
Bear