Ram Pump Help

[cvo]

I built the Mother Earth News PVC water ram, but after 10 minutes of operations it will shut down.

Data:

Head - 18" It takes 20ft of 1.5" PVC to achieve this.

Inlet water - 12 gal./minute

Outlet water - 1 gal./5 minutes

Outlet pipe is a water hose at about 2' above the Ram.

Thanks for the help

[Ungrounded Lightning Rod]

You don't describe the WAY it stops.  Is the clapper valve free but comes up against the seat and chatters or just hangs there?

I'll take a guess, based on the 10 minute behavior.

Check the seal on your air chamber for a pinhole leak.  If the air runs out the action stops.

(I notice the absense of a "snifter hole" in the mother earth design.  This should be a small hole just below the check valve - with a cotter pin or something in it, rattling around losely, to keep it from clogging.  It wastes a tiny amount of water in the waste-valve-closed position and lets in a minute amount of air during part of the waste-valve-open portion of the cycle.

Without a source of air your air chamber will eventually waterlog (as the air in it initally disolves in the water and is lost).  Then the water in the ram pipe won't decellerate gradually and create the pressure regime in the ram pipe that produces the rebound and the momentary drop in pressure that lets the waste valve open.

Of course if you have a small leak in the chamber it will waterlog in minutes rather than weeks.

[Ungrounded Lightning Rod]

Also:

 - Check that the stopper is positioned with the flanges DOWN, so it doesn't wedge into the seat.

 - Check that you have adequate spring pressure to push it down against any residual water pressure.

[Nando]

IT SEEMS that the air in the chamber is the problem.

There are 2 solutions, one as indicated in other message to you.

The second is to get a rubber ( butyl) bladder in the chamber, I have used bicycle tires inner tubes for such purpose, they last around 10 years .

Another possibility is that the valves are not sealing properly.

Chamber air leak

Also an "ELASTIC" OUTLET pipe can be the problem -- ONE needs to remember that the RAM PUMP "pumps" the water to the Outlet pipe and if the pipe or HOSE is elastic it will expand with the RAM action and if the head plus the RAM volume plus the hose expansion rate are about 1 no further up hill pumping. Sometimes the pump continuous operating without any or very little water out or stops. -- RARE -- .

Nando

[Flux]

I replied to this yesterday but comments were disabled.

18" drive head is about as low as you can go with most rams, you can go a little lower with different valves.

Two ft delivery head is too low, normally you need a minimum of 3 times the drive head and more likely 4 times, so think in terms of 6 ft.

Your efficiency when it is working is hopeless, with 12 gpm in and 1/5 gpm out something is wrong anyway.

I haven't seen a drawing of that design so I can't comment much, but if it uses standard plumbing non return valves it may not work at such low head.

Check what the others have said about air ( at that efficiency do you even have an air vessel)

It wouldn't dissolve its air in that time so it would have to be a leak and if that was the problem you would have to drain it each time to restart it.

You also mentioned a loop in the delivery pipe yesterday, if the highest part of that loop is the 2 ft, then your delivery head is even less.

At 1/8" drive head you may have to spring bias the beat valve towards open.

Flux

[jimovonz]

I encountered problems with too low a delivery head on one of my pumps. I was delivering to approx 1.5 times my drive height (10m) and had problems similar to yours (the pump would stop after about 15 minutes with the clack valve shut) The valve needs a certain 'back pressure' in order to reset itself after 'clacking'. If the delivery height is too low and there is too little pressure, you don't get the water hammer effect with the corresponding rebound that sucks the valve back open. I fixed the problem by adding a valve on the end of my delivery line and closing it to restrict the outlet. This obviously reduces the flow rate somewhat - but it has been pumping about a year now with no stoppages. I have another ram that has just under 3:1 delivery/drive height and it works fine. That issue aside, it does seem you are working on the very limit with an 18" drive head.

[Nando]

HECK, I need to stop reading fast 18", I thought that was 18'.

The RAM pipe may need to have it extended higher for proper operation (6 to 8 feet), also, non elastic for the RAMming to operate well.

Nandio

[cvo]

Thanks men for the comments/suggestions.

It works just needs improvements.

jimovonz - that's exactly whats going on, it needs more back pressure and that can be resolved with more head. easy fix.

After more head water and there's still a problem then its got to be an issue wth air, resolved with a bike tube maybe and check for leaks.

The plans from HomePower, thats phase 2. Its easier then the MEN'S version.

Thanks again,

Love this site,

Curtis