Inside a Taco 007 Cartridge

ESGWheel · March 2016

Ever wonder what these sealed cartridges are made of?

While part of another thread on a different form discussing the ability to rebuild a cartridge, replacement parts, etc., this inside look may be of interest to others so posting it as its own topic here.

A couple of thoughts on 'rebuilding' it. While I am not a machinist, I am pretty handy and understand rotating machines fairly well. There is no way IMO that the cartridge can be rebuilt. Its bearings are a ‘sleeve type’ and if one could make a new sleeve (bearing) there simply is no way to get this apart and back together without destroying it.

Reason: notice the sleeve housings have a groove around their circumference. This is what the outer cartridge housing is crimped into along with the clamping rings. And this clamping process has to be a precision process to retain proper relationships between the front and rear bearings. Said another way the face of the two bearings has to be parallel, and the centerline axis of the two bearings has to be same axis, both within a tight tolerance to preclude binding.
Of interest is that I had no radial play in the unit that I could reasonably measure. I.e. when trying to lift the impeller perpendicular to the rotor axis there seemed to be just the ever so slight amount of play which is what I expected. The axial play I measured at 25 thousandths of an inch (0.025") and again that seemed just right. This means that perhaps my Cartridge was ok, as it did not have the excess paly in the bearings I was expecting due to the noise it was making.

Also regarding the possibility of just replacing the impeller. Cannot be done in my opinion.

Reason: it is a press fit, and while possible to get off without damaging the rest of the cartridge with a proper puller, the act of pressing it back on would surely damage the thrust bearing.

The cartridge is 3 years old.

Enjoy

ESGWheel · March 2016

Seems I could not attach all the pics on the first post, so continuing the pics. Apologies now out of order.

ESGWheel · March 2016

Some have suggested that the bearings are ceramic. So I tried to shave off some slivers on both the shaft and the sleeve and could not. So really hard plastic or ? And I noticed the shaft’s coating looks like it was applied while liquid. See pic.

While the combination of these two clues leads me to believe these are a ceramic based bearing it did not make sense to me from a manufacturing process. So I cleaned up the area some (sandpaper) and did a closer inspection under magnification.
The ooze now appears to have a slightly different color to it and is not how I would think it would look if applied after putting the shaft on the rotor. See other pic. Under magnification I saw the coating on the shaft is applied ‘under’ the rotor, i.e. the shaft was coated before inserting into the rotor.

Thus I now think the ooze is cement to glue the shaft onto the rotor. However the way the coating on the shaft sanded down + cannot cut into it, leads me to still conclude it is ceramic based.

ESGWheel · March 2016

Oops, missed the pic on the rotor and shaft seals.
Here they are.

Tinman · March 2016

I admire your curiosity. I, too, take things apart to see how they work and more importantly to see why they fail. Before I return a part under warranty, I carefully go over it to make sure it wasn't our fault that the thing failed. I don't want to be that "guy" in the manufacturer's eyes.

I recently had two Caleffi Z55 zone valves that would power up but only partially open. I carefully took apart the head and found some debris that was jamming the gear. It didn't get there at the factory. It got there on the job. I removed the tiny bit of junk and the valves operates fine.

Curiosity is a good thing.

hot_rod · March 2016

Aqua Motion out or R.I. takes it a step further and allows you to easily dis-assemble that rotor can assembly. It would be handy for DHW circ maintenance, I suppose.

Interesting project you have there

ESGWheel · March 2016

Hot Rod,
Thanks for sharing, I had not seen these before....

I needed to replace my circulator because of noise. And since I had the cartridge, just figured I'd pull it apart for fun and check out what may have been the noise maker. As I stated in the post, the bearings seemed just fine and I could not find a clear source for the noise I was hearing.

If you look at the picture of the water that was inside the cartridge, it does have a fine power like black substance. And since the water inside the cartridge does not constantly flush out I suspect this was responsible for the noise (these particles in the bearings).

This Aqua Motion cartridge you highlighted is designed specially to pull apart, flush out and reinstall. Way cool.

And it does not seem you can get replacement bearings or impellers for it... only 'flush it' or replace it.

On their site for these they state:
"The AquaMotion Replacement Cartridge, CT07, fits the AM7 circulator and the Taco 007 circulators. The CT07 replaces the Taco part RP007-042RP and 007-042 at 20-40% lower cost."

So when needing to replace the very common Taco 007 cartridge, this would be the way to go in my opinion.

However I could not find any for sale after a quick search of the web. The instruction sheet for the installation is dated 2007, so I would suspect they would be out there.

Heck I would probably buy one and install it just for, well for fun

and post my thoughts on it.

hot_rod · March 2016

See if the fine black power sticks to a magnet. If so, it's probably magnetite and adding a magnetic separator is a good way to help keep it out of the pumps. Magnetite is a big concern with ECM type circs, as they have a strong permeant magnet inside that rotor.

We have seen examples of that causing pumps to lock up within a year of installation.

If you have quantities of that black gunk called magnetite, you have O2 getting into the system causing ferrous components to break down.

Even systems that you assume are "air tight" can still allow 02 molecules in. Even barrier pex allows some O2 ingress, especially at high operating temperatures.

In a system that is all copper and iron or steel, pump seals, stem and valve packings, even air vents could allow air and O2 into a system.

I strongly recommend hydronic systems fluids be added to all non glycol systems. One of the key ingredients in those conditioners is O2 scavengers. Another is a film provider which coats out all the surfaces to help protect them from corrosion. Fern, Rhomar, Sentinel, Hercules are some common brands.

But you need to check the fluid every year or two as the inhibitors get consumed and need to be boasted to keep working.

I see Aqua Motion at all the trade shows, but I'm not sure how they are going to market?

ESGWheel · March 2016

Hot Rod,
My system is 25 years old and I was just talking to my neighbor about going together in the year or so on replacement boilers (and seeing who else in the neighbored we can get to jump on the bandwagon) for the cost benefits we could achieve.

And I was not aware of magnetic separators or O2 scavengers, but makes total sense.

So add ons like the DISCALDIRTMAG 5461 which is an Air, Dirt and Mag separator and products like Sentinel x100 will definitely be part of the equation during replacement time! (found these with a quick search of the web based on your comments).

Thanks!

Joe Mattiello · March 2016

Taco 00 pumps have been around for many years, and are synonymous with quality. With so many competitors in a niche industry, Taco continues to enjoy a large population of boiler manufacturers, contractors, and do-it-yourselfers. Although the 00 pumps are of good quality, as mentioned, there are many variables that can cause havoc on the pump. In most cases the pump becomes the sacrificial lamb, because of unfavorable system conditions. I’m glad to see the post about treating the system water to minimize oxygen-attacking, ferrous-system components.

The cartridge assembly is not designed to be rebuilt, because of the complicated manufacturing process, and balancing of the impeller to prevent any vibration while impeller is turning at 3250 rpms. One of the attributes of the pump is the replacement cartridge assembly. Although, replacing it on 007 might not sound economically feasible, because 007 is competitively priced, however, it certainly does on engineered products, like variable speed 00, or Radiant Mixing Block, X Pump Block, Solar Pump Block.

Jeez, I hate to sound like a commercial, but I feel compelled to mention, it’s not only the quality of 00 that differentiates Taco from competition, it’s all the other stuff that makes Taco great.
 Three-year warranty on 00 family of product.
 Excellent 10-person staff of technical support engineers.
 Flo-pro training.
 Webinars and in-house training.
Two-level distribution, to supply products throughout the country, and to better service customers.

Someone mentioned another pump company, and complimented their design, but doesn’t know how they go to market. Taco, believes in developing relationships with customers, it’s not about simply selling products.

Inside a Taco 007 Cartridge

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