Diff-press-valve

jerryb

Can anybody plese supply me with a name of a manufacter who makes a Differential-Pressure Valve for home heating systems 11/2"supply,Used one a while back but forgot name and MOD# Thanks All.

eleft_4

There are others also, Danfoss etc.

Al Letellier

pressure differential control

Try Callefi....

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Ron Schroeder_4

Does anybody make one that can be set down to about 1.5 psi at 4 gpm?

Ron

Kal Row

why 1.5...

the honeywell braukmann D146 in 1.25inch has amazing flow rates and a site-glass that tells you what it's doing and a street price less than 150 - and just use bushings to go from 1.5 to 1.25 and back, unless your flow is more than 50gpm

Kal Row

they are designed for flow not psi...

like i have a system that runs 11.7gpm all zones - but with just the smallest zone open, i adjusted the d146 and watched the little water flow driven indicator until it showed 10gpm which is what has to be bypassed at that point - sure it affects the pressure but it's not important like flow

Ron Schroeder_4

Hi kal,

I have been researching ultra low electric usage hydronics using a lot of zones on a single very low wattage pump (~10 watts). With all of the zones open, the head is about 2.5 feet at 8 gpm. I would like to keep about the same head as more and more zones shut down. I am kind of thinking that a flo-trol valve with an added weight just might do the job.

Ron

Ron Schroeder_4

Hi Kal,

If the zones are balanced, if you bypass at a constant pressure, then the flow PER ZONE will stay constant no matter how many are open. So psi in the loop is more important than flow in the bypass.

Ron

Ron Schroeder_4

Kal,

Isn't the indicator differential PSI, not flow?

I think the 3/4" one might work for me if it truly can be adjusted down to zero. Even the small one would have plenty of capacity.

Ron

Kal Row

of course...and i found the chart

all the ones i have seen are spring loaded regulator types, of course coming off a pump of x pressure and flow, a division of said pressure will mean an proportional division of flow

lets face it, to have true flow control – you would need, a ceramic, gear pump like device, with centrifugally driven bypass valve, inline with the pump, that closes off the bypass as the flow speeds up – and the flying weights would have to have bi-metal springs on them for temp compensation – imagine what the CV on that sucker would be

d146
while it can be adjusted all the way at either end, with the spring compressed all the way or completely unloaded, there is no springiness so it's really acting like a fixed valve rather than a vary valve

see attached pdf

c.t.kay

look at the virtual trade show page .find PAXTON CORP listing,they sell pressure diff. valves . ask for Leif or Nelson.

Kal Row

where do you get such a pump??...

cause i am looking to do a ceiling radiant job with electric tankless like a stiebel-eltron unit - but i want more flow not less - it's the only way to get eveness with radiant - flow reversing via a 4-way and timer is complicated nonsnes - and might sill not get to the middle of the loop where as max flow - with themostatic mixing for btu control would

Ron Schroeder_4

Hi Kal,

There are several low wattage pumps but you need low restriction too.

http://www.lainginc.com has a 30 watt pump, the SM-303B They also make a DC series, the ECOCIRC with 4 models ranging from 3 watts to almost 20 watts.

Ivan Labs makes the El-SID series of pumps that are very low in wattage including a couple designed specifically for Primary/Secondary Injection.

My preferance is the ECOCIRC for my typical applications.

If you look at the ECOCIRD D$ you will see why I want to bypass at under 1.5PSI.

Ron