history of condensate pump

steamfitter

Very curious about when the condensate pump for two pipe steam systems was developed in relation to thermostatic radiator traps.
Was there a time period when thermostatic rad traps and/or F & T traps were used prior to the invention of the condensate pump? Or were they conceived together?
If my memory serves me correctly Dan' LAOS had the basic rad trap beginning on or around 1911. I'm wondering if many buildings struggled with the 'B' dimension to return condensate before the pump was introduced.
I appreciate any historical information.
Thank you!

Jamie Hall

Interesting question. However, since it is unnecessary in two pipe steam systems if the pressure is kept reasonable, is the introduction of the condensate pump more, perhaps, a reflection of steam heating in places where higher pressure boilers were in use for process purposes? There one does often need it -- although a boiler feed pump (which looks much the same, but is controlled differently) is a better solution, if any pump is needed at all...

Pumpguy

I'm thinking way back in the day when steam engines were common in large buildings, a recip steam pump was also used.

Since this is a positive displacement pump, it moved both air and condensate; the condensate being sent back to the boiler while the air was discharged to atmosphere.

Fast forward a few generations, and electric motors now do the work of steam engines, and steam pressure was lowered as a result. Now we needed an electric powered pump to get the condensate back to the boiler.

This supposes that the piping arrangement required condensate to be pumped back to the boiler in the first place.

JUGHNE

Could that have been part of the reason to lower the boiler into a pit to gain on the "B" dimension?

steamfitter

I wonder if lowering the boiler in the pit became more common with two pipe systems.
I know in many apartment buildings in nyc, like the one I grew up in had the boiler in the pit for dimension A on the one pipe steam. But you raise the question of whether this practice became more prevalent with two pipe systems.

jumper

In the olden days before pumps injectors consumed a lot of steam. Gravity works better. Can never have enough A or B dimension.

zackwatt

I'm trying to figure out why a condensate pump was originally installed with my setup...

EBEBRATT-Ed

Gee and I thought they dug the pits instead of raising the chimney to get more draft...LOL

But seriously, some pits were dug to make room for a combustion chamber for the oil burner and not for condensate returns.

@zackwatt by the looks of the piping you may not need the pump.

zackwatt

EBEBRATT-Ed said:

@zackwatt by the looks of the piping you may not need the pump.

Yes, that's my thought. I need to find someone reputable and knowledgeable to do the piping redesign with it deleted.

JUGHNE

Is that a end of steam main trap at the top of the pipe on the right? It has a drip leg and strainer before.

JUGHNE

Another thought about your cond pump. If the previous boiler had a larger water capacity than this one, (it looks like the old boiler footprint is shown on the floor). The pump could have been put in to act as an accumulator to give a little more water storage as condensate may have had a slow return.......usually a feeder pump with a large reservoir may have solved that problem if it existed.

But looking at how your steam mains takeoff of the header the installer didn't read all the advice given here. He maybe just figured you need the pump.

Is there another end of main drip farther to the right matching the strainer/trap that we see above the boiler?

This is 2 pipe steam or not?

Pumpguy

Condensate pump's receiver tank has a float switch, so it definitely is not a boiler feed unit to increase boiler's water storage capacity.

JUGHNE

I am aware of that, a little familiar with both pumps. However the installer may have thought a cond pump would do the function of feeder pump.
The cond pump would contribute a little more water to the overall capacity in the system, maybe the amount between pump on and pump off. From the OP's other post the pump sounds pretty oversized as it stops the boiling of the water, it was recommended to throttle it down. Don't know if that helped or not.

JUGHNE

Steamfitter, back to the history question. Your question and the accompanying posts got me to thinking about a problem project I have and then a bell rang. So bear with me for details.......

I have a 1938 high school that is a 2 pipe, 52 HP NG boiler, (7280 EDR?) feeding about 3840 EDR of CI rad and fan coils. 2 3" zone valves control this.
Terrible water hammer with very slow cond return, LWCO would feed and flood boiler with worse hammer on next cycle.
There are 2 dry returns and one wet return. Only the wet return went into the cond pump. The 2 dry returns teed and went thru a check valve and then dropped into the discharge of the cond pump. Pump went into a Hartford loop.
Finally realized there was only 23" of "B" dimension with a boiler running at 7 PSI.
Lowering the pressure to 2.5 PSI helped somewhat, but re-piping the dry returns into the cond pump solved many of the problems.

The biggest hurdle to think this thru was that the boiler was installed in 1973 by a major contractor from the big city. I assumed that their piping plan was correct and there was some simple thing I was overlooking.

But this boiler was installed in 1973 to replace the one in the 1913 building (connected to the 1938) that was torn down. This current boiler is in the basement level that was built outside the 1938 building, has a concrete deck above the boiler room.
Someone did confirm my suspicion that the original 1913 boiler was lower than where it is now. Another perhaps 4' lower than the current basement. The 1938 return piping did look as if it was a wet gravity return going to the 1913 boiler.

Don't know if this helps your history investigation or not.
Probably no cond pump for 1913, non added for 1938, and only one added badly in 1973. Actually the 1973 install looks like an afterthought from analyzing the cut in to old pipe and being connected with a 25' extension cord (the rest of the electrical looks done more properly).
FWIW

So would a 1913 boiler have a condensate pump?? There may not have been electricity available out here then. There possibly were not even hot water pumps available then, let alone condensate pumps.

zackwatt

JUGHNE said:

Is that a end of steam main trap at the top of the pipe on the right? It has a drip leg and strainer before.

Yes it is, you can see it better in this photo:

JUGHNE said:

Another thought about your cond pump. If the previous boiler had a larger water capacity than this one, (it looks like the old boiler footprint is shown on the floor). The pump could have been put in to act as an accumulator to give a little more water storage as condensate may have had a slow return.......usually a feeder pump with a large reservoir may have solved that problem if it existed.

But looking at how your steam mains takeoff of the header the installer didn't read all the advice given here. He maybe just figured you need the pump.

Is there another end of main drip farther to the right matching the strainer/trap that we see above the boiler?

This is 2 pipe steam or not?

It is two pipe steam, and you can see more of my setup below. Does my steam header need to be addressed as well?

JUGHNE

Zackwatt, I have been away for a few days, you might consider bringing your first post up to date, it may get more attention there rather than under the history title.