On 7/1/2011 11:37 AM, Brooklyn1 wrote:
On Fri, 01 Jul 2011 06:10:11 -0500, The Daring Dufas
wrote:

On 7/1/2011 4:31 AM, FarmI wrote:
"Bob wrote in message
...
Stormin Mormon wrote:
First thing comes to mind, is sunlight and the UV rays. So,
what you use should be UV resistant.

White PVC tubing might work for a while. The cost of
fittings might add up. Typically sold in 10 foot lengths,
and the tubing is relatively rigid.

White PVC will be weakened by UV. Works great buried.


The new "Pex" stuff they sell for indoor water tubing may
work, but not sure how UV resistant it is.

Most Pex is easily damaged by UV.


They also sell some grey tubing for electrical conduit,
which might be more UV resistant, but not sure it's used for
outdoor water.

It's not rated for that.

Which brings us back to black poly pipe.

Ah! Thank you for mentioning it. Given all the other posts where there has
been no mention of black polypipe except for a very early post, but some
other things I've never heard of and UV, I was beginning to wonder if black
polypipe hadn't made it to US.



Back in the late 1950's and early 1960's, 2 inch black poly pipe is what
my father used to get water from our spring's pump house to the
water system at our home on the farm. We had to make sure the buried
pipe was in a bed of sand because 200 yards of plastic pipe will move
when pressurized. On more than one occasion a small stone would rub
a hole into the pipe so we had to dig it up, patch the pipe with a
plastic coupling then rebury it with sand around it. I remember the
pipe as having a fairly thick wall and not being very flexible.

I never heard of buried poly moving from being pressurized... perhaps
your system was prone to air locks, which is easy to eliminate by
installing a simple device that cushions the system. Anyone
installing an irrigation system from their domestic water needs to
install an anti backflow valve or they are looking for big trouble.

Oh it had a check valve at the pump but the pipe went straight for a
distance then down into a gully where the spring was located. No matter
what material a pipe is made of, it's going to move when pressurized.
Pipe will also move with a change in temperature. Look at how metal
pipe is supported in different situations. The longer the pipe the more
movement becomes a problem.

TDD