Megaflow cold feed.

[Dannypipe]

Gray, where do you order your gledhill parts? From your merchants or do you have a number? Only asking as I have to order some tomorrow and it's going to take me a while phoning around. Cheers in advance!

 

[Gray0689]

Dannypipe
I get cylinders and parts from Bassetts

 

[Dannypipe]

Oh right, just a local merchants. I'll try my guys in the morning then cheers. If not, I'll have to ask my wife to get on the phone. I get rubbish reception where I'm working tommorow!

I need a few bits for two different thermal stores. Rod stat without a thermal lockout and a few valves. My usual ebay source has closed his account. Very odd.

Cheers.

 

[ferret]

I stand corected
I only use range or tempest or gledhill cylinders
Never used megaflow my suppliers dint stock them

I,m sorry i thought the original thread was a mega flow , maybe with a tempest or gledhill a 4 bathroom house will run fine on 22mm when all taps and the w/machine dishwasher are in use. 😀 Now i,m no expert on the correct flow rates from taps etc but i can hazard an educated guess after working in the trade for 33years that 22mm will not do it correctly unless the whole house is run in microbore!!😡

 

[Gray0689]

I have done a 7 bed 7 ensuites
smart cylinder
22mm hot and cold feeds no problem at all

 

[ecowarm]

I have also done a very large farm house, 4 full bathrooms and two kitchens, 8 bedrooms and coped with parents 5 kids and several shooting parties.

The water main was upgraded to 32mm and then 28mm to dual 250l megaflo's then 28mm hot and cold balanced supplies, 22mm seconary return.

This is a very large house over three stories.

Normally 22mm is fine, doing a flat at the moment and its having 15mm supply to the unvented cylinder and balanced h/c and will be fine.

 

[ferret]

yeah fine if using taps with 8mm and 10mm connections , it aint fine with standard 22mm and 15mm connections , there would be too much pressure drop when taps etc are opened , I know that probably all taps etc won,t be open at the same time but system design should be based on the possibility that they are. ... pressure and volume = flow rate wether water or gas 😛

 

[justlead1]

Hi. In support of Ferrets correct facts. I would like to add, when working with direct mains feed systems. i have found the fluctuation of mains pressure to be the fly in the ointment. And have witnessed it to change up to 5 fold from night to day (owing to peak demand) These condition will reduce the flow some 60 percent. Hence the need to up the supply pipe sizes where possible.

 

[ecowarm]

the flat mentioned above is owned by a one armed hermit with no friends so only 1 tap turned on 😉

 

[Dannypipe]

In fairness, Ferret is right. I was called back to a bathroom suite I installed. The client complained that when she runs her bath the basin runs at a dribble.

The bath is 22mm, as it should be and basin 15mm. Both are taken from the 22mm that enters the bathrooom from an unvented cylinder.

I told her water will take it's easiest route. She said I was talking rubbish.

The supply to the unvented is 22mm with a brass pump and secondary flow loop. It's a bloody big house. Glad I didn't install the cylinder! Though in fairness they did a lovely job, perhaps they should have consulted this forum first!

Anyway, I'm off to work. Have a good day one and all!

 

[Gray0689]

That's nothing to do with whether it's 22 mm
That's the pressure in system I bet if you check the flow rate coming in on mains is to low if the pressure and flow rates where correct it would not happen

 

[Gray0689]

I think you mean it's got a seconderry return

 

[so-solar]

all this talk about a 28mm supply, what if the mains incomer is 25mm? just like a site i have just finished! the agent still insisted no a 28mm virgin main to the megaflo! you can run whatever size you like but if it is bigger than the incoming mdpe then it is a waste of money!

 

[Gray0689]

If the incoming mains is of the higher pressure and flow than needed the pressure reducing valve takes it down to the correct pressure
So if the correct checks are done before a cylinder is fitted 22mm is the correct way to do it

 

[so-solar]

so, if you do not get the required readings after doing your checks and you have an incoming 25mm main, you would automatically step up to 28mm?

 

[ferret]

If the incoming mains is of the higher pressure and flow than needed the pressure reducing valve takes it down to the correct pressure
So if the correct checks are done before a cylinder is fitted 22mm is the correct way to do it

OK OK you obviousley know best😉 I give in! , your right! , I,m too old for this game my brains gone all senile i,ll have to call it a day😛🙄

 

[Gray0689]

so, if you do not get the required readings after doing your checks and you have an incoming 25mm main, you would automatically step up to 28mm?

So solar
if the incoming mains was of the wrong pressure and flow putting up to 28 ain't going to do it
You could upgrade mains (with a he'll of a lot of work if not ducted from mains and which are)

Or you would have to have a cwsc and then pump from there to cylinder
Would you not do this?

 

[ferret]

P+V=F not P+F=V🙄

 

[Gray0689]

P+V=F not P+F=V🙄

And does that make me wrong??

 

[ferret]

And does that make me wrong??

Yes but you wont have it , so no if you want lol😛😛😉

 

[so-solar]

gray, are you an installer?

 

[Gray0689]

Yes so solar Why??
I also instal solar too

 

[so-solar]

cool, what solar systems you installing? have you had much to do with this drain back system mate?

 

[Gray0689]

cool, what solar systems you installing? have you had much to do with this drain back system mate?

So solar
I was installing viessmann but got a lot of problems with air in stainless flexi pipe
Now use kingspan thermomax these are great very easy and quick to install and never had to go back to any would recomend them highly

Never used the drain back system am ment to be going to look at a set that don't work lol

 

[natwill]

i appreciate everyones imput. Ta.

 

[Blackcatgas]

But what would be best to connect to?, a 1/2 inch lead supply giving 25ltrs a minute@ 3bar or a 32mm mdpe supply giving 14ltrs @ 1.5bar, its not the size that counts somtimes.

 

[justlead1]

Well said.The fault is not knowing the difference.

 

[ferret]

But what would be best to connect to?, a 1/2 inch lead supply giving 25ltrs a minute@ 3bar or a 32mm mdpe supply giving 14ltrs @ 1.5bar, its not the size that counts somtimes.

so you think that 32mm pipe supplying at 1.5bar will only give 14ltr/m , go do some maths then come back with a sensible reply.😛😛

 

[Toddyplumb]

That would be approx 9litres sec or 540 litres minute😉 neglecting frictional losses

 

[Blackcatgas]

so you think that 32mm pipe supplying at 1.5bar will only give 14ltr/m , go do some maths then come back with a sensible reply.😛😛

if you had a kinked a 32mm pipe you could have a standing static pressure 0f 1.5 bar supplying 1 ltr a minute, if you really wanted to.

The point Iam trying to make is, you are limited by what you have coming out of that stop tap into the house, you can connect a 28mm pipe to it, but if youve only got a low amount coming in it wont make a blind bit of difference, save for say a small amount of frictonal loss through the pipe.

 

[ferret]

No because you will still have 28mm volume at 1.5bar until there is enough flow taken off to cause a significant pressure drop at the inlet then it would flow as incoming , however depending on the length of 28mm installed it would need to be a significant amount to cause this , the 28 would act as a buffer/accumulater. 😉🙂

 

[Gray0689]

Blackcatgas
I agree with you you can't make more than you got coming in to house

 

[Blackcatgas]

No because you will still have 28mm volume at 1.5bar until there is enough flow taken off to cause a significant pressure drop at the inlet then it would flow as incoming , however depending on the length of 28mm installed it would need to be a significant amount to cause this , the 28 would act as a buffer/accumulater. 😉🙂

Lol were splitting hairs here🙂, youd get that untill all the initial water was purged out of the 28mm, so youd get 28mm flow @1.5bar until the 28mm had emptied.

 

[ferret]

Thats exactly what i,m saying and that applies to everything including megaflows which was the original thread , as long as you have the volume and pressure it will give the required flow , if you only start with low volume you will never get the flow . 😀(Gray i,m afraid you know nothing😛😛😀)

 

[Toddyplumb]

So if .......LOL😉😉