Can I use a Twin impellar pump to boost hot pressure only..?

[Water Systems]

Just do as I say. Forget the other odd suggestions.

Feeding hot to both sides of the pump wasn't your suggestion in the first place.

It was. But at least I never said put a PRV on. :

 

[Water Systems]

Thanks again. Think I'll give that a go.

Bigburn, what does cavitate mean??

http://en.wikipedia.org/wiki/Cavitation

 

[Softus]

Just do as I say. Forget the other odd suggestions.

Feeding hot to both sides of the pump wasn't your suggestion in the first place.

It was.

You've got the words "was" and "wasn't" mixed up.

But at least I never said put a PRV on.

No, but you wish you had, since it's the easiest and cheapest of the effective options.

 

[Water Systems]

Just do as I say. Forget the other odd suggestions.

Feeding hot to both sides of the pump wasn't your suggestion in the first place.

It was.

You've got the words "was" and "wasn't" mixed up.

But at least I never said put a PRV on.

No, but you wish you had, since it's the easiest and cheapest of the effective options.

Are you kidding? Are you serious? A PRV? ...I actually think you are serious?

And a equalisation valve compensates for any pressure imbalances as the shower is being used...like a toilet being flushed. A PRV does nothing like that.

 

[Softus]

And a equalisation valve compensates for any pressure imbalances as the shower is being used...like a toilet being flushed. A PRV does nothing like that.

Quite so. Perhaps you read that somewhere, or it could be that you're not as stupid as you make out.

 

[Water Systems]

And a equalisation valve compensates for any pressure imbalances as the shower is being used...like a toilet being flushed. A PRV does nothing like that.

Quite so. Perhaps you read that somewhere, or it could be that you're not as stupid as you make out.

"Perhaps you read that somewhere," A personal sneer as you have lost it. Typical.

I fact, I am quite brilliant.

 

[Bigburn]

MON5TER wrote

Bigburn, what does cavitate mean??

Its pockets of gas arising inside a pump due to loss of suction head and may result in damage to the pump as the bubbles collapse.
If cavitation and loss of suction head does occur, it can sometimes be cured by increasing the pressure in the system, either by alteration of the layout to provide a greater hydrostatic pressure or a reduced pressure drop ion the suction line. Sometimes ,slightly closing the valve on the pump delivery or reducing the pump speed by a small amount may be effective.

That extract was taken from "Chemical Engineering " volume one courtesy of Proffessor J.M Coulson. Hope it makes it a bit clearer for you.

My earlier solution still stands. Take a separate feed from the cistern in the loft and you may need to change your cistern to 50 gallon capacity or alternatively change the float valve to a high capacity type if your mains flowrate is good thus allowing you to keep the existing cistern.
You could lash some 22mm plastic pipe in quite easily. Just follow the same route as the cold feed to your hot cylinder and then follow the route that the hot supply takes from the hot cylinder.
Most pump manufactureres also recommend siting the pump close to the base of the hot water cylinder also and I think this manufacturer also specify this .

 

[Softus]

"Perhaps you read that somewhere," A personal sneer as you have lost it. Typical.

The forum is littered with your personal sneers, so it's a bit late to get high and mighty. Or are you just trying to get your posts deleted, like last night?

 

[doitall]

Why not take the pump back and change it for a single one.

or;

Change the shower for a low pressure model, all you need to do then is fit the pressure equalisation valve, and, a non return valve on the hot.

 

[Softus]

Why not take the pump back and change it for a single one.

Not reading the topic is certainly the easy option.

or;

Change the shower for a low pressure model, all you need to do then is fit the pressure equalisation valve, and, a non return valve on the hot.

Here we go again with the incredibly expensive solutions.

 

[Bigburn]

Doitall Wrote

Change the shower for a low pressure model, all you need to do then is fit the pressure equalisation valve, and, a non return valve on the hot.

Do you mean fit no pump at all Doitall ??

 

[Water Systems]

"Perhaps you read that somewhere," A personal sneer as you have lost it. Typical.

<snip Mr Softus>

Mr Softus, you lost it.

 

[Softus]

you lost it.

Well, patting all my pockets, I'm certain that everything is still here. You need to be more specific.

 

[doitall]

Doitall Wrote

Change the shower for a low pressure model, all you need to do then is fit the pressure equalisation valve, and, a non return valve on the hot.

Do you mean fit no pump at all Doitall ??

If you changed the shower valve, you wouldn't need the pump.

The pressure equalisation valve is the cheapest and best way to balance the hot with the cold.

 

[Softus]

If you changed the shower valve, you wouldn't need the pump.

If you're going to do that you might as well then you might as well buy a shower valve that incorporates an EV.