The most important part of the pump is the 'drive pipe'. Here is a view down it's 60' length. In spite of the way it looks in this photo, it's actually pretty straight. One can see a section of the 6' of plastic pipe going to the stand pipe which I mention on another page.


Note: Rigitity is the most critical aspect for good performance. I've used 1 1/4 steel pipe which was scrapped after being pulled from a well. I forgot or never knew what gauge...schedule 40 maybe? In theory (mine), it actually shouldn't matter a whole lot whether it bends or not, but a bent drive pipe will be difficult to secure and thus, should be avioded.

Note: This pump is actually quite loud. The noise is a metalic clank that seems to emenate from every point on the drive line. It got louder when I secured the pump to the block of concrete mentioned below. If the noise proves to be offensive at some point, I will bury the drive line.

Here is a picture of the pump in operation. The valve has just snapped shut. I had access to some very nice stainless steel fittings and happily, an industrial check valve that someone had obtained from Wearhauser's scrap yard 20 years ago. Almost everything you see here is stainless and of heavy gauge.


Note_1: The reason for the configuration is that I wished the check valve to be 'upside-down' so that pebbles and rocks would be less likely to screw things up and I could flush them. The upshot is that one may take liberties with whatever designs one might happen across.

Note_2: Instead of an air bleed 'snifter valve', I have put a wheelborrow inner-tube inside the bounce chamber. So far, so good...the thing isn't too critical anyway as far as dimensions go (my theory.) Even at the valve on the pump when it is cracked to produce 60 psi of back pressure, I see no indication of a pulsating delivery which surprised me.

Note_3: The valve and gauge have proven to be invaluable as it is necessary to have quite alot of back pressure in order for *my* pump to cycle. I partially close this valve and watch the gauge (so I don't blow the pump up) when starting it if for some reason the native 50 psi is not available (i.e., the line to my tank is not full.)

I do not know why my pump requires so much back pressure. I suspect it has to do with the rigidity of everything and/or the plastic at the end of the drive pipe and/or the over-sized body and too long neck to the valve and/or the hight of the stand-pipe.

Note_4 There is a huge amount of force generated by the water-hammer in the drive pipe. It made the pump jump around alot so I welded on a mounting bracket and poured a 700lb block of concrete around a large boulder which I found under the surface of the ground. That did the trick! Also, as I mentioned, the pump got generally louder. My opinion is that proper securing of the pump is second only in importance to rigidity of the drive pipe.

Note_5 As for the preformance, I recently put over 1800 gallons of water in my tank in 24 hours, and the tanks is somewhat over 110 feet above the pump. I've not measured the waste rate, but a ratio of 1/5 is expected for an efficient pump if I recal correctly. I'm curious now, and will measure the waste flow rate when I get a chance. BTW, the cycle frequency of my pump seems to be more than once per second...download the movie clip if you like. 750K Movie Clip if you like. Lengthening the drive pipe from 40' to 60' didn't change the frequency as much as I expected.

Update: I got around to measuring the waste. It's around 6 gal/min. This makes it slightly better than 1/5 at it's current state of tune and workload.

My valve design differs somewhat from other descriptions I've seen, but I'm happy with it. I had three worn out foot valves from the former (traditional) water system to choose from when making this one.:



Note_1 I replaced the valve stem by sawing off the original and carefully drilling and tapping the disk. The new stem is a high quality stud which does not have threads where it goes through the support. Under the disk, I screwed on a second nut and set the threads with a punch. I wanted plenty of weight so I left the stud long and took up the slack with a tight fitting bit of fuel line hose (which is camoflauged in this picture.) The double-nut on the top allows me to adjust how far the valve drops into the body (and thus, in theory, the water flow needed to snap the valve shut), but I've not needed to fool with it.

Update: After around 30 days of run-time, there is a noticable amoung of wear where the valve stem goes through the support. Steel-on-brass, and the brass is wearing. Apperently the stem slaps the guide as the valve seats with enough side-force that it is wearing. Next I'll try either a gas engine valve guide or a teflon insert depending on what I can fit to the valve housing...unfortunatly there is little extra material on the foot-valve bodies that I have kicking around.

Note_2 Note that the valve is actually sucked open with some force by a 'reverse wave' in the drive pipe. This creates stresses to be aware of and is a failure mode for some pumps and can cause noise. In my system, the fuel line hose slipped over the stem reduces both of these problems. The drive-pipe clank noise is much louder than the clack valve in my pump.

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