Fresh Water Demand Pump Lift Capacity

[oldjohnt]

Of course, I generally prefer the fresh water demand pump at or below the level of the tanks outlet so gravity feeds the pumps suction inlet and it don't have to lift any whatsoever. HOWEVER I'm installing an auxiliary fresh tank with no more then 3 feet of 1/2" inlet suction hose BUT THE PUMP WOULD BE ABOUT 6 INCHES HIGHER then the auxiliary tanks outlet, so the pump would have to lift about 6 inches max when the water level is near the bottom portion.

 

QUESTIONS: Are those typical fresh water demand pumps (Mines a Shur Flo 35116 or something like that) capable of lifting maybe 6 inches????

 

Even if so, its not going to loose prime each time and have to pump back up each use????

 

Would an inline check valve on the suction side be required or of any use???

 

I guess once I hook it up (if mounted in current location) it will be easy to find out the answer lol. There's just no place to mount it so its higher then the pump grrrrrrrrrrrrrrrrr

 

John T Plumbing just aint my cup o tea

[Darryl&Rita]

When the tank's full is the time to recharge any lost prime, so as long as the tank top is higher than the pump, I'd go for it. Once prime is established, water out has to pull water in. Other than the built in check, I'd stay away from any type of checks on the suction. The idea being that any check valve will introduce a restriction on the line, and increased restrictions will increase the chances of issues.

[Dutch_12078]

The ShurFlo Revolution pump is rated to dry prime up to 6'.

 

ShurFlo Revolution 4008 Data Sheet

[Zulu]

If you need a new pump, I recommend the Remco Aquajet ARV it can prime up to 13 feet.

[oldjohnt]

Thanks gang, no I don't need a new pump, mine works perfect and pumps to 50 PSI, I'm just wondering if it will LIFT 6 inches ???? and from what I see Ima thinking NO PROBLEM lets hope so, I will know in a few days once I hook up the auxiliary tank.

 

MISTAKE ALERT my old RV had a Shur Flo, this one is a Flo Jet, works great so far.

 

John T

[Ray,IN]

John, if it looses prime the diaphragm has a leak/hole. If the pump is ran dry and I then try to pump up to pressure without opening a faucet it will not prime. I must open a faucet first, then it primes easily.

[oldjohnt]

Good Neighbor Ray, as a matter of fact I just today 2 hours ago got the aux fresh water tank all hooked up and it primes, pumps and maintains good pressure, and is still working, even though it has to LIFT the water maybe 6 inches yayyyyyyyyyyyyyyyyyyyyy.

 

HOWEVER as we already know there cant be even a teeny air leak in the suction side or it will drain back, loose prime and cant pick it back up. How do I know ?? I already did but find its still true lol. Earlier today I had a small leak grrrrrrrrrrrrrrrr. After I went back and refreshed and tightened and sealed all the suction side hose barb and hose clamp connections and tightened her all down, there's no more teeny air bubbles and she don't drain back out and holds its prime (suction inlet line stays full) and pumps fine.

 

I added an auxiliary tank to my existing fresh water as my goal is to be able to dry camp at least 7 days before we have to dump and take on water as the case when were in the Colorado or Utah mountains on BLM or Natl Forest lands.

 

Life is good

 

We gotta visit sometime as we live so close. I go to Frank Baileys sometimes on Sundays to his Bluegrass jam, I take it you live southwest of Bloomington.

 

John T