For Low pressure with Unvented Cylinders
- Thread starter ln1234
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Yes, put the pump before the combination valve. If you plan to fit unvented you need a qualification to do so and have to inform building control of your plans in advance in advance, and it's a good idea to inform the water board for your area.
You should also pump the cold to the shower for equal pressures.
Your proposal doesn't increase mains pressure into cylinder. The cold water tank must be open, so you then have a tank fed supply which you then pump. I can't see the point of this myself. What is your mains pressure (static)? If the flow is too restricted, you could upgrade mains supply pipe or use an accumulator to boost flow to unvented.
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Yes I should have made it clear the storage tank must be a complete break from the mains. This is a recognised means of obtaining sufficient flow of water in difficult areas, there are parts of Britain where even with the right pipework you can't get suffitient flow. The water board legally only have to supply water to your tap, there is no specification for pressure or flow rate.
There is, but there might as well not be! It varies between regions but hereabouts it's 0.7bar at the communication pipe and 7 l/min.
If your supply is worse than that for more than 2 spells one hour long within a four week period, you can claim compensation from your water supplier. It isn't worth much but I can't remember the £ amount. The other figs are a bit vague now too!
If your mains is really poor you're allowed to pump it, but again, at 7 l/min it's hardly worth the bother. You need permission first too.
If your supply is worse than that for more than 2 spells one hour long within a four week period, you can claim compensation from your water supplier. It isn't worth much but I can't remember the £ amount. The other figs are a bit vague now too!
If your mains is really poor you're allowed to pump it, but again, at 7 l/min it's hardly worth the bother. You need permission first too.
I've not used any. But any expansion vessel attached to an unvented cylinder can act as an accumulator if incoming flow doesn't match outgoing flow. I think it is OSO who market large expansion vessels as accumulators along with their unvented cylinders. The principle seems very simple so I can't see why any generic expansion vessel (suitable for potable water) shouldn't be used. Of course I would value your thoughts on this.
There IS a Patent issue. You can only buy the Oso acc WITH the unvented cylinder and they charge hundreds for it. I called inquiring about just the acc and they said I would be sued etc if I employed a tank as an accumulator!
I expect you know where to buy biggish ones - email me if not. I haven't used one , and would be very interested to know how well they work.
I expect you know where to buy biggish ones - email me if not. I haven't used one , and would be very interested to know how well they work.
I think OSO are just huffing. How could they do anything in practice? Personally I am surprised that they can patent a use of standard plumbing component. It's like someone trying to patent use of a 6" length of copper tube as an air trap. I certainly intend to try it out when the occasion arises. As for suppliers, I presume we both follow the star.
I agree - I was annoyed not to be able to buy one from Oso. The constructon could vary according to the application. eg Surge tanks would get different conditions in use.
And yes, the one who rides around in the Ford.
And yes, the one who rides around in the Ford.
If OSO's accumulator is significantly different from a surge tank, then surely their patent would have no bearing on the use of a surge tank. As for the performance conditions of a surge tank, I wouldn't have thought they were very different.
I'm thinking that the rubber diaphragm might be arranged differently. I can guess at what a surge tank would be used for but I don't know how its pressure would vary over time. I agree, the patent sounds daft!
As far as I know (which is not very far in this case) all potable water expansion vessels / surge tanks will have a diaphragm in the form of a "balloon" with the mouth sealed to the pipe connection flange. In this way there is no water contact with steel vessel. At maximum expansion the balloon will fill the steel vessel, but at minimum expansion (no water pressure) it will be pressed in on itself by gas charge pressure.
I can't think of any other practical arrangement, unless vessel is stainless steel. Apart from that, it's hard to imagine how OSO's accumulator might be significantly different. Possibly a better quality diaphragm I suppose. Of course the gas charge pressure must be adjusted for optimal operation of the accumulator.
I haven't been able to decipher your Ford reference. For some reason that suggests Orion to me. I thought we were taking about something like Mars, as the Greeks would have said.
I can't think of any other practical arrangement, unless vessel is stainless steel. Apart from that, it's hard to imagine how OSO's accumulator might be significantly different. Possibly a better quality diaphragm I suppose. Of course the gas charge pressure must be adjusted for optimal operation of the accumulator.
I haven't been able to decipher your Ford reference. For some reason that suggests Orion to me. I thought we were taking about something like Mars, as the Greeks would have said.
hydraulic accumulators work the same way
ie balloon in the bottle
ie balloon in the bottle
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