ceramic coating on impller

[upm]

Gents,
any body has an experince on ceramic coating on duble suction pump impeller? this is to avoid the errosion wear we are having in the service. if so, do i need to coat the impeller and the wearing rings? if yes, then i need to work out the new running clearances as the thermal expansion is different, am i correct???how can i calculate the new required clearances??
SS-316 impeller and SS-410 wearing rings can be an option for an errosion wear???
regards

 

[Parado]

hi upm,
Please give more info on service medium.

 

[upm]

it is a process water including 30% benzen. the service is very dirty as hard polymers are formed at the suction side of the pump. strainers got blocked so fast causing the pump to cavitate. fine polymers are passing through and causing an abrassive wear to the impeller, volute and wearing rings.

 

[macmil]

Our company has successfully coated impellers with urethane to protect against occasional solids (typically sand) for instance during spring ruboff in water service. One of the benefits is this can be done on partly worn impellers; it is usually cheaper than new impellers, and can be done again and again. You would need to check the chemical compatiblity re the benzene. (We also do ceramic coating, but have stayed away from impellers as because of they are a large and intricate surface area making for a complicated application, and concern re impact )

 

[dadfap]

upm

in oil well pumps, we have had success with both a teflon coating and also tungsten carbide coating of stages.

The teflon stage imparts some protection against solids and an added benefit has been some increase in efficiency.

The TC coating was done for a customer who wanted a slightly harder coating on a ni-resist stage

all the best

dadfap

 

[upm]

dadfap
Thanks for the info.
the other problem is the process tempereture which is from the range of 130 to 150 deg C and i doubt teflon or neoprene will fit such temperature range.
how can i work out the new weraing rings clerances? do impeller and wearing rings to be coated to the same hardness?
upm

 

[dadfap]

upm

what we did was spray and then remachine the areas necessary.

also, we use tungsten carbide inserts where we need to improve radial stability.

All the is on submersible multi stage centrifugals.

all the best

dadfap

 

[dadfap]

upm

was looking through some old files this morning and came across another coating that may interest you.

It is called Fluidglide developed by a company called Corrocoat. There was an article in World Pumps Nov 1991 that went into quite a bit of detail on this.

It added corrision resistance and also some efficiency points were gained. I was looking at them in Australia at

http://www.corrocoat.com.au

and they have an enquiry address enquiries@corrocoat.com
It is a while since I looked at their products but they may help.

All the best

dadfap

 

[upm]

thax alot gents,
i will give them a call
upm