Valves used for solar applications:
Frost valve:
Once installed should have the exit
point facing
downwards
(permits total drainage) During frosty conditions the valve
opens to release a slow flow of
water through the collector/s
until the water temperature rises enough to close
it.
Frost valves should be fitted at the hot water exit end of
the
collector on an extended 300mm of un-insulated pipe.
This valve is used as a backup to the controllers frost protection.
These valves can also be used in a thermosiphon system where
no solar controller is fitted.
Frost valves are not a fully reliable method of frost
protection.
Heat rejection thermal pressure relief valves:
Hot water systems must have some way of releasing pressure
in the event of failure.Solar hot water collectors need
an
independent relief system of the cylinder itself,(without
this
relief the cylinder can explode)-this is achieved by either
a
relief valve (TPR) or open vent. Relief valves must not
have
isolation valves installed between the heat source and the relief
dischargepoint.(drain all roof valves to the
gutter).
It is important not to oversize the system.
The SR868C6 solar controller will not control overheating.
Relief valve:
The pressure relief path is to be sized for
the total output of
the solar hot water system @ 99 deg c and
1500 w/m2 and
45 deg c ambient temperature plus any additional heating
source.
Roof material/valves:
Caution must be taken where these valves discharge on
to
building roofs or other material,discharge will damage surfaces
if adequate care is not taken.When freezing occurs these
discharge locations need to be of such a length freezing wont
occur.An air break or tundish is required to be piped away
safely,if in doubt check the valve manufacturers specifications
or someone qualified to assess the problem.
Roof penetration:
It will be necessary for both pipes and electrical
cables to
penetrate the roof. Roof penetrations should be done as per
standard practice using either lead flashings
or rubber dectite
seal as required.Care should be
taken the integrity of the roof
is not compromised.
Detailed solar collector roof fixing method comes
in the kit.
Solar hot water air release valve:
3/8" m 5 bar/ 80 psi:
Tempering valve 20mm:
Max pressure
1mpa
Max temp (in) 120 deg c
Operating range 35-60deg c
Copyright 2010
Solar thermal pressure relief valve
Solar hot water valves
solar hot water collector valves
