water in my cat

[Desk Jockey]

Looks oxidized, strong acids or salts???

 

[Aero Tech XT]

Mike, Thank you for bringing this to our attention.

The brass seal that you have shown is actually exposed to the atmosphere....meaning the corrosion is occurring from the outside, not inside the pump manifold and from a contaminant in the water.

Here is a picture of the water pump.



Here is an old manifold we had laying around showing the seal.

so.....what is corroding the exposed brass? I would suspect its from water dripping from the vacuum hose as it gets rolled up....???

 

[Aero Tech XT]

Or...
The AT is not Last Step injection like I thought and this is the result of the MW 02 rinse I was using..

Yes our chemical injection system is a last step injection. The diaphragm in the chemical pump is rated for 1500 psi so it wont be effected when cleaning tile and grout. We also have the ball valve between the chemical pump and water pump so you can shut off the chem pump when its not needed.

The only way chemical can get into the water pump is if the diaphragm fails. If the diaphragm fails, the flow meter would be showing a chemical draw when your not triggering the wand.

 

[Able 1]

Not exactly. My (probably incomplete) understanding is that cavitation occurs when there is rapid fluctuation in local pressure below the saturated vapor pressure of the water. Temperature is involved because the pressure where cavitation occurs (at a given pressure) goes up as temperature rises. So, increasing the inlet pressure and/or reducing the liquid temperature can cure cavitation.

When the piston draws in liquid through the inlet plumbing and past the inlet valve there is always some pressure drop. Poor plumbing (tubing too small, restrictive fittings) make the situation worse. The water level above the pump inlet makes a difference as well. The higher the level - the more pressure (head, as the pump guys say) is exerted at the inlet, helping the situation. Make the pump draw water uphill (water box below pump) creates low pressure (vacuum) making the situation worse.

You can create cavitation at any temperature (with enough inlet restriction and/or low enough inlet pressure) but high temperature makes matters worse (much worse, as you approch boiling).

Do you think if I tapped a fitting for a bigger hose on the water box, and choke it down right at the pump create enough pressure? If so how much bigger would I have to go?

 

[Lee Stockwell]

I went through all my inlet side fittings and replaced or drilled out any that were restrictive.

 

[dgardner]

Making the plumbing bigger doesn't add/create any pressure, it just reduces pressure drop. One size bigger than the inlet would be my suggestion (like 1/2" inlet - use 3/4" hose).

The height of the water in the water box above the pump inlet is what creates the pressure, slight as it may be.

 

[Able 1]

Is that on your 405?

 

[dgardner]

Lee makes a good point - some fittings are super restrictive - really choked down.

 

[Able 1]

Mine has 3/4 hose, I'll take a look at fittings..

 

[dgardner]

Excessive hose length, unnecessary bends/kinks.... you get the idea.

 

[Zee]

Gotta be the Snickers bar...can't be good for the Cat pump.

Remove Snickers...tear wrapper..insert into mouth....feel better..