fred wrote:
In article .com
, Harry K writes
fred wrote:
In article .com
, writes
Your system uses a pump; the cabin where the ranch owners want water
does not have any electricity (nearest power line is 22 miles away) so
it must all be gravity fed. Elizabeth wants hot water, however, so an
on-demand propane heater will probably be used. Since there will be no
tanks at the cabin, perhaps we will skip the pressure relief valve.
I was going to ask you what you were using for hot water as that will likely
be the weak point regarding pressure. Ok, no tanks, fine cylinders for that
kind of pressure would be expensive. Just check that your hot water heater
can take the pressure you are talking about, preferably +50% as you are
likely to get pressure surges when a tap is turned off hard or say when a
washer stops filling, derating helps with longevity.
--
fred
Plusnet - I hope you like vanilla
Any standard hot water heater or well storage tank will take pressures
way over that 40 to 50 psi he is talking about and they are not
expensive. Not needed in his installation though.
I suppose that depends where you come from. If you come from places
where mains pressure hot water storage is not the norm then that is not
the case. A lower pressure tank can always be made for less than a high
pressure one.
Your view of pressures is not consistent with
reality. Consider that many tires take a static
50-60 psi and all are at least 35psi rating; when
you hit a bump psi goes high. Bicycle tires
normally run these days from around 50 psi to 125
psi. At my house the city pressure is 70-80 psi
and no one has a problem with the pressure. Any
metal pipe can easily take a pressure of at least
100 psi and any water heater is designed for an
even higher bursting pressure. Really cheap poly
pipe is made for 80 psi, better grades are rated
at 120 psi and higher. And of course almost all
lawn hoses will take a minimum pressure of 70=80
psi and most are fine with quite a bit more
(especially if you don't leave them pressurized in
the sun at 105 degrees. Even food grade
polyethylene (very soft plastic) will take 40-50
psi as long as you don't let it get hot.
As for tank costs, a 20 gallon air tank rated for
125 psi can be bought for less than $25. And you
can buy new empty 5 gallon propane tanks that will
take very high pressure for $20.