I was looking at
third-world solutions (PDF's) for well-pumps to get ideas for a manual pump
that could be lowered into my well-casing in the event of a grid-down SHTF
scenario. I decided to play a bit in the shop and prototype 'my' version
of a lift-pump.
The bottom disk on
the lift rod is the 'flap valve' made of a circle of neoprene rubber (valve
and guide - 2). I added a second disk to minimize binding of the flap
valve when the lift rod is operated. The brass check-valve at the bottom
is the only style available yesterday at Home Depot. I would have
preferred an in-line style check-valve that could be mounted inside the 1.5 in
PVC cylinder. A piece of hobby-shop brass tube is slipped over the
threaded rod and secured with nuts to provide a smooth surface and minimize wear
at the top cap. I would use unthreaded rod in a 'production'
pump.
I noticed the
diameters of the valve and guide disks have to be sized for the
specific PVC chosen for the pump cylinder. There is enough variation
in the internal diameter of several scrap pieces of 1.5 inch Type 1 Schedule
40 PVC that the disks are loose in some and won't fit others.
This was the only "critical" parts dimension. The neoprene circle was
trimmed "proud" of the disk with scissors.
Several web sites described similar hand operated
lift pumps that could be used at depths down to 100 ft. For
short depth of my well (30- 40 ft ... water at 20 ft) the lift rod could be
1/4-20 threaded rod. For deeper wells I would use lengths
of commercially available fiberglass lift rod.
This prototype is
clearly a throw-away experiment, but it operates with low friction and really
does a great job of pumping out my rain buckets ! With a few
minor design changes to the lower check-valve, riser pipe and addition
of lever style pump handle, I could envision lowering 30 ft of this
into my well-casing.
No comments:
Post a Comment