A plumbing question - would this work?
Discussion
We have 3 showers all with independent pipe runs fed from a hot water cylinder and a header tank in the loft but the pipe runs are long and therefore the system lacks pressure.
Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
Kentish said:
We have 3 showers all with independent pipe runs fed from a hot water cylinder and a header tank in the loft but the pipe runs are long and therefore the system lacks pressure.
Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
No. You really think the "pressurised" water will choose not to exit via the few small holes? Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
No - will not work.
Any piston that tries to 'increase pressure' in such a way would need to be 'water-tight' and you drilling holes in it would defeat the purpose!
Either raise the tank, use pumps (you can get self contained hot/cold feed thermostatic showers now that run off 3A and are very easy to fit) or consider fitting a 'megaflow' pressurised system. Or replace the piping to the showers with 22mm instead of 15mm.
Many ways to solve this, but a bit of polystyrene with weights on and holes in will not work and will just sink.
Any piston that tries to 'increase pressure' in such a way would need to be 'water-tight' and you drilling holes in it would defeat the purpose!
Either raise the tank, use pumps (you can get self contained hot/cold feed thermostatic showers now that run off 3A and are very easy to fit) or consider fitting a 'megaflow' pressurised system. Or replace the piping to the showers with 22mm instead of 15mm.
Many ways to solve this, but a bit of polystyrene with weights on and holes in will not work and will just sink.
victormeldrew said:
Kentish said:
We have 3 showers all with independent pipe runs fed from a hot water cylinder and a header tank in the loft but the pipe runs are long and therefore the system lacks pressure.
Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
No. You really think the "pressurised" water will choose not to exit via the few small holes?Just a little more pressure would make it more acceptable.
I know to fit a pump is the long term answer but for the moment I'm considering putting an expanded polystyrene 3" thick sheet in the tank to fit exactly inside the tank to float on the surface and then sit weights on top to give downward force and act like a piston. I'll leave a few small holes in the sheet for the fresh water entering the header tank to eventually equalize and the styrene to float.
Does that sound like it will work?
Not if the smaller holes are less than the area of the pipework orifices.
The small holes may not even be required if the styrene doesn't fit tight to the sides of the tank. Water will always take the easier route and as long as there is no larger escape route for it then the main one will be the pipes to the showers.
Kentish said:
We have 3 showers all with independent pipe runs fed from a hot water cylinder and a header tank in the loft but the pipe runs are long and therefore the system lacks pressure.
Shirley it's not the length of the pipe runs that reduce the pressure but the head of the system?If you could raise this than that would increase the water pressure.
You havent studied Engineering or Physics ..... have you ?
Increase the hydrostatic head by making the tank about 1 metre deeper.... just gaffer tape some boarding around the tank , seal the gap between boards and tank with some bath sealant ...... and hey-presto , a deeper tank
Guaranteed it wont leak if you apply the tape carefully.
Increase the hydrostatic head by making the tank about 1 metre deeper.... just gaffer tape some boarding around the tank , seal the gap between boards and tank with some bath sealant ...... and hey-presto , a deeper tank
Guaranteed it wont leak if you apply the tape carefully.
In theory, whatever weight you place on top will be your increase in head of pressure as long as that weight isn't great enough to sink the styrene then (in theory) it should work.
The assumption is also made that the styrene is a very close fit to the tank walls so that the easiest route for water to escape will be down the pipe.
It's a round tank BTW (not that it makes any difference).
The assumption is also made that the styrene is a very close fit to the tank walls so that the easiest route for water to escape will be down the pipe.
It's a round tank BTW (not that it makes any difference).
esselte said:
Kentish said:
We have 3 showers all with independent pipe runs fed from a hot water cylinder and a header tank in the loft but the pipe runs are long and therefore the system lacks pressure.
Shirley it's not the length of the pipe runs that reduce the pressure but the head of the system?If you could raise this than that would increase the water pressure.
As water flows through a pipe it loses pressure due to 'friction loss', the length does matter. Hence me saying use 22mm instead of 15mm - less friction loss.
Kentish said:
In theory, whatever weight you place on top will be your increase in head of pressure as long as that weight isn't great enough to sink the styrene then (in theory) it should work.
The assumption is also made that the styrene is a very close fit to the tank walls so that the easiest route for water to escape will be down the pipe.
It's a round tank BTW (not that it makes any difference).
The assumption is also made that the styrene is a very close fit to the tank walls so that the easiest route for water to escape will be down the pipe.
It's a round tank BTW (not that it makes any difference).
The ONLY thing increasing the pressure in the tank will be the water depth victormeldrew said:
Trying to be helpful however ...
The length of the pipe runs will have little effect on pressure. A larger tank might - which would be similar to raising the existing one. Fit a second tank and run some of the outlets from that?
The length of the pipe runs will have little effect on pressure. A larger tank might - which would be similar to raising the existing one. Fit a second tank and run some of the outlets from that?
The length of pipe DEFINITELY has an effect on pressure: www.diydata.com/planning/ch_design/pressuredrop.htm
anonymous said:
[redacted]
That depends on the natural bouyancy of the polystyrene sheet and how much weight is above it.
I'm pretty certain it will work to some extent but dependent on getting the diameter of the sheet correct and the weights above it and the even distribution of that weight.
I'll do some math when I get home too see whether it is feasible. I'm an ex-hydraulics design engineer so I'm quietly confident
Kentish said:
That depends on the natural bouyancy of the polystyrene sheet and how much weight is above it.
I'm pretty certain it will work to some extent but dependent on getting the diameter of the sheet correct and the weights above it and the even distribution of that weight.
I'll do some math when I get home too see whether it is feasible. I'm an ex-hydraulics design engineer so I'm quietly confident
But surely all you would be doing is getting the sheet neutrally bouyant and cancelling the effect. i.e. more bouyant the sheet is, more weight you can put on it, however the resultant downward force would not change.
As long as there is somewhere else for the water to go (i.e. up through the sheet) it is pointless.
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