Feed Pump Pressure Drop

[Amber Gold]

Danno. This is the pump I'm running.

http://www.grainger.com/Grainger/GOU...B56?Pid=search

Where's the shutoff sensor?

[Brent]

Our RO is only rated 150 GPH by Airablo with the original PVD-1 membranes and it has the same series Gould pump

BUT it is 1 Hp. -- on a smaller system than yours. I think the pump simply undersized.

By the way I change the plumbing on ours and even though the pump intake is 1-1/4", the first fitting I put on the pump is a reducer to 1" and it still puts out almost exactly 50 PSI, so I don't think you have a problem on the intake side, unless you have a huge amount of
elbows etc.

Going back to my earlier idea, see if a nearby guy will loan you a 1 Hp pump to test. You only need to turn it on for 30 seconds and you
may have the solution to this issue.

[danno]

Josh -

The max head for that pump is 62 feet. 62 feet of head converts to 26.87 PSI. If you want more PSI, I think you need to change pumps. They do sell larger impellers for some of these pumps, you can also take a look at that option. SS impeller is probably gonna run you $150ish. If you go the larger impeller route, check the head rating on it first, it may not get you much more PSI.

For the shut off switch, just follow the 1/4" or maybe it's 5/16" (anyway, the smallest hose on the RO). It probably comes off the hose that runs between your prefilter and high pressure pump or it may come right out of the top of your prefilter housing. That small hose runs into a reverse pressure switch which is what automaticvally stops your pumps when the pressure drops.

I've seen it clog, but I think your problem is an under headed pump.

think that's your problem

[Amber Gold]

Danno...hadn't thought of calc'ing what it should be. I got the same result. If that's what the pump's rated for, then it's working fine and I'm happy. I was just thinking if mine's running @ 32psi, yet everyone else's is running 50-60 psi, then there's something wrong w/ it...guess not. I'll check the pressure line to confirm.

Brent, swapping feed pumps w/ a friend's would need to be a post-season check, but something I'm intersted in doing.

[Amber Gold]

Spoke to Lapierre and he said if the pre-filters are clean and the impellers are clean, then everything's fine. He said generally, those are the only things which reduce the pressure. He also said my 2.25-2.5gpm flow rate during a wash/rinse cycle is fine as well.