How hot...(ME)

Mike T., Swampeast MO

Well above the point where the T&P should have dumped the system.

Friction in the absence of water to cool, e.g. "cavitation"?

[Deleted User]

I'm guessing SOME BODY knows the answer to this question...

How hot do you suppose it got inside of this Taco dubl ott somethings volute?

This is a freckle faced red headed step child we inherited a while back. This is from his snowmelt system (1/2" tube 12" OC)

Any guesses from the peanut gallery?

How's about the Cranston Contingent?

ME

Steve Ebels_3

I'm guessing

That the impeller is made of some sort of reinforced Delrin.......or something like that...........just guessing. But I'd bet that you would have to see on the + side of 350* to melt that puppy.

Deadheaded?

PS: A goggle turned up the following chart.

http://www.machinist-materials.com/comparison_table_for_plastics.htm

Mark Hunt_3

Looks familiar


and I would have to guess WAY in excess of 250°.

Several years ago(in another life) I worked for a company that did work for a local college. We were tasked with running "bench warmers" for the biology department's green house.

The physical plant maintained 285° water through the entire campus. Shell and tube HX's were used at each point of use. I recommended a simple manual reset high limit to prevent a run-away situation, but the college already had a standing contract with a local building management company.

Long story short..the BMS's control would fail open. Meaning there was NO high limit protection for the connected system. 285° water melted everything, even the rubber on the handles of the ball valves. The circ's looked just like the pic you posted.

What were these connected to??

Mark H

Mark Hunt_3

No T&P on a hydronic system Mike


Just pressure relief.

The temp can go as high as it likes.

Without high temp protection, no way to safe guard this.

Mark H

hot_rod

I'd guess in excess of 350F

most circs that are rated for solar use better have 350F ish temperature handling ability.

I believe the 00 series are being used on the solar module Taco offers.

The bigger question is WHY it got as hot as it did. looks like a brand new circ without water, or moving liquid, in the system.

hot rod

[Deleted User]

Wha hoppened...

My partner, Tom Olds discovered the debacle. There were two 00 pumps on the load side of a flat plate heat exchanger where the fluid temperature from the source was limited to 180 degrees F. Pretty sure they are OK due to manual high limits, which did not trip.

There is a small glycol feeder on the load side of the system. It normally sits about 1/2 full. For whatever reason, the check valve on that feeder quit doing its assigned job, and let the fluid back into the reservoir of the feeder. There is a snow switch on the system that calls for the load, and source pumps, and send a high temp call to the boilers. We surmise that after the check valve failed, there was a snow event, which called on the pumps and boilers. THe load side pumps had lost their loop, and these two 00 pumps (in series) were running their little hearts out, with no fluid movement. The other 00 pump's impeller fell completely off during disassembly.

I'd show you all pictures of the systems involved, but it would make the other current posts about bad systems, look good...seriously.

ME

hot_rod

a fuseable link circ... how clever

no if it could only drop the voltage some how.

Kinda like the early mod con fan plastic impellers

hot rod

Weezbo

probably 287->320+

and or something trashed the first circ's impeller it just spun to beat the band then the next cirulator took to trying to pump pieces of the circ , deadheading and it rattled the pieces apart... as a sorta wild guess.

heatguy

swag

that would be called a swag: scientific wild a** guess