Armstrong E Series

Zman

I am working on a fix for a misguided snowmelt design and need a high head/ low flow circ.
Does anyone have experience with the Armstrong E12.2.
I have never used this series and am wondering about reliability.
I am hoping for an operating point around 12-15 GPM and 45-48 ft/hd.

Harvey Ramer

I used one for a similar circumstance. Don't remember the model. The first pump lasted 3 years and then the threaded end of the stainless drive shaft popped off. When I pulled it apart, I noted evidence of cavitation in the cast iron housing. The second pump is still going strong.

Zman

Harvey Ramer said:

I used one for a similar circumstance. Don't remember the model. The first pump lasted 3 years and then the threaded end of the stainless drive shaft popped off. When I pulled it apart, I noted evidence of cavitation in the cast iron housing. The second pump is still going strong.

Thanks Harvey,
They advertise a bunch of design improvements which made me wonder if they had issues.
With that steep a curve, I am sure maintaining high system pressure is imperative.
The existing setup is Taco 0013 in series. I wonder how Taco feels about that setup. @Steve Thompson (Taco)

Harvey Ramer

They may have had, I don't know.

You are correct on the system pressure. Also keeping the pump as close to the supply header as possible is also a good idea. Assuming that's where the PONPC is.

hot_rod

Pumps in series is sometimes a better approach as you can find the lower flow circs in smaller sizes, in series head doubles.

And the cost is usually lower with two common off the shelf circs.

Steve Thompson (Taco)

I have no problem with series pumping as long as:
- At 6 pipe diameters between the pumps (insures laminar flow into the downstream circ)
- Both pumps (circs) need to run at the same time. if you pump into an off ECM for example and spin the impeller the motor could generate power and burn out the electronics (or worse).
- Both pumps (circs) should be the same size, running at the same speed etc.
- Extremely common in Geothermal (they call it "push/pull" but it's really series pumping.
- Not limited to just two.

Steve Thompson (Taco)

BTW, the Armstrong "E" series is not a bad pump - and we all update/upgrade our stuff. The nature of the beast.

hot_rod

The GEO guys commonly put 4 circs in series, two pull, two push. And on open systems!

Nice seeing you in Chicago, Steve.