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CWatters
Guest
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 Posted:
Wed Nov 23, 2005 9:35 am Post subject:
Know about plumbing? |
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Got a plumbing problem....
The mains water pressure in my house is 5bar (let's call it 5 Volts) but my
heating system is only rated for 3 bar (3V) so I've installed a 3bar
pressure regulator (=3V voltage regulator). That works fine with no water
(current) flowing but as soon as I turn on the taps (load up the regulator)
the pressure/voltage falls to <1bar (1V). It's behaving exactly like a
voltage regulator but with a high source impedence.
Anyone know if better quality pressure regulators are available or is this
typical?
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Gerard Bok
Guest
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| Posted:
Wed Nov 23, 2005 11:37 pm Post subject:
Re: Know about plumbing? |
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On Wed, 23 Nov 2005 08:07:06 GMT, "CWatters"
<colin.watters@pandoraBOX.be> wrote:
| Quote: | Got a plumbing problem....
The mains water pressure in my house is 5bar (let's call it 5 Volts) but my
heating system is only rated for 3 bar (3V) so I've installed a 3bar
pressure regulator (=3V voltage regulator).
|
Maybe plumbing is much like electronics: Read the manual :-)
Carefull: this is just my guess:
Describe your heating system. Is it a single heater to provide
both hot water and heating to your building ?
In that case, the circuits are separated. The heating system
operates on 1 to 2 bar, with a 3 bar maximum.
It's contents gets pumped around, but it is not connected to the
water supply (OK, about once a year it is, because you refill the
system. But the hose you use keeps the pressure well below 5 bar
:-)
The hot water part of your system (boiler) is connected to the 5
bar water supply. But it is also well designed to operate under
this pressure.
So, it is quite like electronics.
You try to solve a problem that is no problem at all :-)
--
Kind regards,
Gerard Bok |
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Ken Taylor
Guest
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| Posted:
Thu Nov 24, 2005 1:35 am Post subject:
Re: Know about plumbing? |
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"CWatters" <colin.watters@pandoraBOX.be> wrote in message
news:KqVgf.55288$kA7.3568770@phobos.telenet-ops.be...
| Quote: | Got a plumbing problem....
The mains water pressure in my house is 5bar (let's call it 5 Volts) but
my
heating system is only rated for 3 bar (3V) so I've installed a 3bar
pressure regulator (=3V voltage regulator). That works fine with no water
(current) flowing but as soon as I turn on the taps (load up the
regulator)
the pressure/voltage falls to <1bar (1V). It's behaving exactly like a
voltage regulator but with a high source impedence.
Anyone know if better quality pressure regulators are available or is this
typical?
That could well be typical. I have the same setup in my 'new' (read: new to |
me but a century old) house and it behaves in the same fashion, though I
haven't measured pressures. And that's with new (installed during
re-plumbing of house) pipes and pressure-reducing regulator. Do you actually
get hot water out in sufficient quantity to have a hot shower?
Cheers.
Ken
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CWatters
Guest
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| Posted:
Thu Nov 24, 2005 1:35 am Post subject:
Re: Know about plumbing? |
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"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:vJ4hf.3243$vH5.185860@news.xtra.co.nz...
| Quote: | Do you actually
get hot water out in sufficient quantity to have a hot shower?
|
Yes but it's very unsatisfactory. With 3bar of pressure it should be much
better. I know it can be because...
There is also a 3bar over pressure relief valve designed to protect the
heating if the regulator fails. If I temporarily remove the pressure
regulator the 3bar relief valve opens to limit the pressure to 3bar (think
5V power supply with a 3V zenner diode clamp on the output putting it into
current limit). In this situation I get 3bar at the shower head, good flow
and everything is perfect...except I waste huge quantitiies of water through
the relief valve (current through the zenner). This experiment demonstrates
that the pipes are still in good order etc.
I guess I'll just have to look for a better quality regulator - one that
doesn't restrict the flow so much. |
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CWatters
Guest
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| Posted:
Thu Nov 24, 2005 1:35 am Post subject:
Re: Know about plumbing? |
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"Gerard Bok" <bok118@zonnet.nl> wrote in message
news:438466c9.2616829@News.Individual.NET...
| Quote: | Carefull: this is just my guess:
Describe your heating system. Is it a single heater to provide
both hot water and heating to your building ?
|
Yes.
| Quote: | In that case, the circuits are separated.
|
All understood.
| Quote: | The heating system
operates on 1 to 2 bar, with a 3 bar maximum.
|
Yes that's correct. I've no problem with the heating side (A sealed rad loop
operating at 1.5 bar)
| Quote: | It's contents gets pumped around, but it is not connected to the
water supply (OK, about once a year it is, because you refill the
system. But the hose you use keeps the pressure well below 5 bar
:-)
The hot water part of your system (boiler) is connected to the 5
bar water supply. But it is also well designed to operate under
this pressure.
|
Your description is correct. It's a mains pressure hot water system but the
max mains input pressure rating is 3bar not 5 bar hence the need for a
regulator. There is a 3 bar over pressure relief valve on the mains input in
case the regulator fails.
I've installed pressure guages at various points now and it's clear the
problem is with the pressure regulator - it's just not "ideal" enough. It
drops the 5bar down to 3bar ok but it doesn't open enough when the pressure
is reduced by turning on a tap (too much internal resistance).
See also my other reply to Ken. |
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default
Guest
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| Posted:
Thu Nov 24, 2005 1:35 am Post subject:
Re: Know about plumbing? |
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On Wed, 23 Nov 2005 08:07:06 GMT, "CWatters"
<colin.watters@pandoraBOX.be> wrote:
| Quote: | Got a plumbing problem....
The mains water pressure in my house is 5bar (let's call it 5 Volts) but my
heating system is only rated for 3 bar (3V) so I've installed a 3bar
pressure regulator (=3V voltage regulator). That works fine with no water
(current) flowing but as soon as I turn on the taps (load up the regulator)
the pressure/voltage falls to <1bar (1V). It's behaving exactly like a
voltage regulator but with a high source impedence.
Anyone know if better quality pressure regulators are available or is this
typical?
|
If you are doing something like measuring the drop with the flow wide
open - you will see a big difference - because the outlet pressure is
essentially at zero. So that isn't a good measure of effectiveness.
You are probably concerned because the flow isn't what you expected.
Flow is determined by the size of the regulator. Generally, if the
pipe threads match the pipe, you are plumbed with the right size.
You may have a problem - but I don't think your test is valid.
Any chance there's a restriction in the pipe? Some debris that got
into the regulator inlet, a valve not fully open, etc..
Make sure your regulator is good for the application you are using it
in. There are some low flow pressure reducers for replenishing water
closets on toilets - those do lower both pressure and flow.
--
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spudnuty
Guest
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| Posted:
Thu Nov 24, 2005 9:35 am Post subject:
Re: Know about plumbing? |
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In the common hydronic heating systems in the states the supply to the
furnace has an inline pressure regulator to protect the closed heating
system. The furnace will also have an over pressure blow off regulator
on it and in older system an expansion tank.Hot water for faucets and
showers is a separate supply running at house pressure ~ 70PSI or 4.8
BAR.
If you're drawing hot water off behind the regulator for a shower I can
see how the pressure would be greatly reduced.
The regulators I deal with look like the ones on this page:
http://www.plumbingsupply.com/waterpressureregulators.html
Except they have an over ride lever on the top. When we refill a system
we over ride the inlet pressure regulator othewise the system will take
hours to fill.
3 bar would be at the low end of an acceptable home supply. >1 bar
would be miserable! |
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CWatters
Guest
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| Posted:
Thu Nov 24, 2005 9:35 am Post subject:
Re: Know about plumbing? |
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"spudnuty" <spudnuty@lycos.com> wrote in message
news:1132804315.272611.41800@g43g2000cwa.googlegroups.com...
| Quote: | In the common hydronic heating systems in the states the supply to the
furnace has an inline pressure regulator to protect the closed heating
system. The furnace will also have an over pressure blow off regulator
on it and in older system an expansion tank.Hot water for faucets and
showers is a separate supply running at house pressure ~ 70PSI or 4.8
BAR.
If you're drawing hot water off behind the regulator for a shower I can
see how the pressure would be greatly reduced.
|
No what I have is...
Mains in -> 3bar pressure regulator -> Safety valve -> Tank -> Hot taps and
shower
A closed primary loop (at nominal 1.5bar) circulates water from the Furnace
to either the Rad loop or a coil in the tank to heat the water. There is a
manual valve (normally closed) between the output of the safety valve and
the primary loop. This is used to adjust the pressure in the primary loop.
This only needs to be done once a year as it stays around 1.5bar. There
probably is another safety pressure relief valve somewhere in the furnace
enclosure for the primary loop.
Yes that looks very much like the reducer I'm using.
| Quote: | 3 bar would be at the low end of an acceptable home supply. >1 bar
would be miserable!
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Humm. Sounds like my tank/furnace has a low rating. |
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CWatters
Guest
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| Posted:
Thu Nov 24, 2005 9:35 am Post subject:
Re: Know about plumbing? |
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"default" wrote in message
news:rqq9o1h36vmei0n9unj1rlaoi5sv576p8a@4ax.com...
| Quote: | On Wed, 23 Nov 2005 08:07:06 GMT, "CWatters"
colin.watters@pandoraBOX.be> wrote:
Make sure your regulator is good for the application you are using it
in. There are some low flow pressure reducers for replenishing water
closets on toilets - those do lower both pressure and flow.
|
That sounds like a good possibility. There is almost no data on the
packaging for the reducers available locally. Will try and find a better
supplier. |
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Gerard Bok
Guest
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| Posted:
Thu Nov 24, 2005 5:25 pm Post subject:
Re: Know about plumbing? |
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On Wed, 23 Nov 2005 22:44:02 GMT, "CWatters"
<colin.watters@pandoraBOX.be> wrote:
| Quote: | "Gerard Bok" <bok118@zonnet.nl> wrote in message
news:438466c9.2616829@News.Individual.NET...
The hot water part of your system (boiler) is connected to the 5
bar water supply. But it is also well designed to operate under
this pressure.
Your description is correct. It's a mains pressure hot water system but the
max mains input pressure rating is 3bar not 5 bar hence the need for a
regulator. There is a 3 bar over pressure relief valve on the mains input in
case the regulator fails.
|
Strange.
I took out the paperwork from my own heater. ('Nefit HR
combiketel'). And it accepts 0.9-10 bar input water pressure.
(And 1-3 heating system pressure.)
--
Kind regards,
Gerard Bok |
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spudnuty
Guest
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| Posted:
Thu Nov 24, 2005 5:35 pm Post subject:
Re: Know about plumbing? |
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<colin.watt...@pandoraBOX.be> wrote
| Quote: | No what I have is...
Mains in -> 3bar pressure regulator -> Safety valve -> Tank -> Hot taps and
shower
A closed primary loop (at nominal 1.5bar) circulates water from the Furnace
to either the Rad loop or a coil in the tank to heat the water.
|
So is it like one of these systems:
http://www.eere.energy.gov/consumer/your_home/water_heating/index.cfm/mytopic=13020
And what I don't understand is why it isn't set up like this:
Mains in I-> 3bar pressure regulator ->Boiler-> Safety valve ->
I> heat
exchanger>I
Mains in---cold water inlet--4.8bar-----------------> Tank -> Hot taps
and shower
The only time I've seen pressure regulators on taps/shower supply is
when the inlet pressure is too high >60-70 psi |
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CWatters
Guest
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| Posted:
Thu Nov 24, 2005 5:35 pm Post subject:
Re: Know about plumbing? |
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"Gerard Bok" <bok118@zonnet.nl> wrote in message
news:4385a1d8.979433@News.Individual.NET...
| Quote: | Strange.
I took out the paperwork from my own heater. ('Nefit HR
combiketel'). And it accepts 0.9-10 bar input water pressure.
(And 1-3 heating system pressure.)
|
I'm beginning to see the light... The hot water that comes out of the taps
never goes near the boiler/furnace. Only the primary circuit goes between
the hot water tank and boiler/furnace...so... I need to be looking at the
spec for the tank NOT the boiler itself. Unfortunately I don't have that.
Anyway I made some progress today. The main pipe to the hot water tank with
the pressure reducer in is 15mm (call it 1/2"). Upto now I had a 1/2"
pressure reducer in the line because everyone said to match the size. Today
I changed it for a 3/4" regulator of the same 3bar rating. With no water
flowing the output pressure is the same as before (adjusted to just under
3bar) but now when you turn on a tap/shower the pressure only falls to
around 2 bar instead of 1 bar (ish) - much better.
It looks like the 3/4" regulator has less internal resistance than the 1/2".
Thanks for the ideas. |
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CWatters
Guest
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| Posted:
Fri Nov 25, 2005 1:35 am Post subject:
Re: Know about plumbing? |
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"spudnuty" <spudnuty@lycos.com> wrote in message
news:1132850980.518705.159650@g43g2000cwa.googlegroups.com...
Yes, this one......
http://www.eere.energy.gov/consumer/images/indirect_water_heater.gif
| Quote: | And what I don't understand is why it isn't set up like this:
1) > Mains in I-> 3bar pressure regulator ->Boiler-> Safety valve -
I> heat
exchanger>I
2) > Mains in---cold water inlet--4.8bar-----------------> Tank -> Hot taps
and shower
|
Well it's very similar except the regulator on the secondary circuit (2) is
3 bar not 4.8 bar and there is a 3 bar safety valve in case the tank boils.
I think I need to find data on the tank to see if I can replace these two
with 5 bar parts. That's going to be the best solution.
The primary is sealed and topped up by a tap rather than a regulator. This
tap is normally closed and almost never needs to be used. Perhaps once in
the last five years? |
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spudnuty
Guest
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| Posted:
Fri Nov 25, 2005 9:35 am Post subject:
Re: Know about plumbing? |
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1) > Mains in I-> 3bar pressure regulator ->Boiler-> Safety valve ->
| Quote: | I> heat
exchanger>I
|
2) > Mains in---cold water inlet--4.8bar-----------------> Tank -> Hot
taps
| Quote: | and shower
Well it's very similar except the regulator on the secondary circuit (2) is
3 bar not 4.8 bar
I don't understand why there needs to be a pressure regulator on that |
side of the circuit. This would be the case only if your supply
pressure exceeds 120 psi or so ~ 8.5 bar! Check this out:
http://www.popularmechanics.com/home_improvement/home_owner_clinic/1275231.html
and:
http://www.askthebuilder.com/192_Water_Hammer_-_How_to_Stop_the_Bang_.shtml
(talking about inlet pressure reducing valves) "Factory settings are
usually between 50 and 60 PSI. I happen to prefer a setting of 70 PSI.
Settings at or near 70 PSI allow you to take vigorous showers." That
would be 4.8 bar
| Quote: | and there is a 3 bar safety valve in case the tank boils.
Well that is the job of the TPR valve which usually vents out the top |
of the tank into a drain. These are both thermostatic 210ºF and
pressure 150 psi (10.32 bar!!) all US figures. See:
http://www.usinspect.com/WaterHeaters/HWaterTPRValve.asp
and these not only prevent boiling but conditions were a hot water
heater can become superheated and explode. Think of a 50 gal
superheated steam rocket!
| Quote: | I think I need to find data on the tank to see if I can replace these two
with 5 bar parts.
I think we're talking about separate issues here with the 2 valves. |
Make sure that second valve is a TPR valve and blows off to the
outside. These will have a manual overide so they can be checked
regularly
| Quote: | The primary is sealed and topped up by a tap rather than a regulator. This
tap is normally closed and almost never needs to be used. Perhaps once in
the last five years?
This primary would also have a TRP valve and that's good that's good |
there's a valve because as it seems the way your system is hooked up
there is the chance of backflow from the boiler into the hot water side
of your system.
So if this valve is closed the inlet pressure regulator is out of the
circuit?
I think the inlet water pressure of your hot water supply tank could be
at city pressure unless that exceeds 8.5 bar or so.
I just looked at this indirect system and they also recommend the use
of a cold water inlet pressure releaf valve set at 150 psi.
http://www.johnwoodwaterheaters.com/pdfs/GSW_Indirect_Installation_Manual.pdf
This would also blow off into a drain. |
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Jasen Betts
Guest
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| Posted:
Fri Nov 25, 2005 4:39 pm Post subject:
Re: Know about plumbing? |
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On 2005-11-23, CWatters <colin.watters@pandoraBOX.be> wrote:
| Quote: | Got a plumbing problem....
The mains water pressure in my house is 5bar (let's call it 5 Volts) but my
heating system is only rated for 3 bar (3V) so I've installed a 3bar
pressure regulator (=3V voltage regulator). That works fine with no water
(current) flowing but as soon as I turn on the taps (load up the regulator)
the pressure/voltage falls to <1bar (1V). It's behaving exactly like a
voltage regulator but with a high source impedence.
Anyone know if better quality pressure regulators are available or is this
typical?
|
sounds like it may be stuck valve or partial blockage in the pipes
to or from the regulator.
if it is the regulator more regulators can be paralleled to increase the
flow capacity.
Bye.
Jasen |
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