Pumping Away

Re: Pumping Away

PostBy: Rob R. On: Mon Nov 25, 2013 10:06 pm

It has to do with the pressure differential created by the circulator and the point of reference.
Rob R.
 
Stoker Coal Boiler: EFM DF520
Hand Fed Coal Stove: Hitzer 50-93
Other Heating: Dad's 1953 EFM Highboy

Re: Pumping Away

PostBy: KLook On: Mon Nov 25, 2013 10:16 pm

I would guess the lowest pressure is just before and the highest is just after due to friction in the pipe? As has been said, it is a push me - pull me so it should be equal.

Kevin
KLook
 
Stoker Coal Boiler: Harman VF 3000
Coal Size/Type: rice, bagged, Blaschak
Stove/Furnace Make: Harman (Back In Maine)
Stove/Furnace Model: VF 3000

Re: Pumping Away

PostBy: Sting On: Tue Nov 26, 2013 9:29 am

lsayre wrote:Water is not compressible, and what goes around comes around in equal measure. so I must admit to being confused by the entire pumping away vs. pumping too issue.


As usual Larry you are correct regarding the compression - but there is a significant variation in pressures in any system. When designing a system from scratch - its very ez to place the circulators correctly, but when "hacking" systems as so many here find themselves doing to make something work - well its gets a little more exciting, and because water does not compress it will change pressure while carting energy in you pipes.

What goes around comes around??? It depends --> I once walked on to a job where the last lowest bidder attempted to fix a no heat call - by fitting in a pump that was 4 times too large - it pulled air into the system past its seal because the point of low pressure was so low on its intake side. Other examples can be found in all that drivel I used to spew regarding System Balance.
Sting
 
Other Heating: BurnHAM=NG-gas


Re: Pumping Away

PostBy: lsayre On: Tue Nov 26, 2013 4:57 pm

Thanks for the explanation Sting!
lsayre
 
Stoker Coal Boiler: AHS S130 Coal Gun
Coal Size/Type: Anthracite Pea
Other Heating: Resistance Boiler (It has been fixed!)

Re: Pumping Away

PostBy: Dave 1234 On: Thu Nov 28, 2013 12:02 pm

(Sting wrote ) Other examples can be found in all that drivel I used to spew regarding System Balance.[/quote]

Sting , you have opened my eyes many times. ( love some of your avitars 8-) ) I grew up fixing all things that go fast and never had experience with heating.
As you said , to hack , adapt, or add a coal boiler into an existing system can be a challenge. I agree with the reasons for " pumping away " and only add this post for some other guy who faces a challenge of space being practical only on return for his pumps.

I have an old two loop mono-flow system than gave yearly air bound troubles. She was fired by an oil burner.
I read 3 times, Stings posts about mono-flow and balance and decided to keep the system while replacing the oil boiler with a coal fired one. My buddy Rich and I re-piped most of the copper surrounding the boiler and because of very little clearance we gave into mounting the two pumps on the returns up by the floor joist.

We have lived here 30 years, this is the first year with great heat, plenty of DHW, and no issues. I only air bleed the system on install.

So from my very limited experience I say, do the best you can and don't sweat what is the unachievable,the quest for perfection.

Many Thanks Sting ! And all for lending your help.

Dave
Dave 1234
 
Stove/Furnace Make: EFM
Stove/Furnace Model: 520