Pipe Material selection for 10% hydrated Lime slurry 1

[Tilley95]

Hello all,

I am working on selecting pipe material for a 10% By weight lime & water slurry.

A previous use of this pipeline shows carbons steel but a spec. I'm reading convinces me I need Stainless.

Does Carbon steel not have a risk of corrosion from the hydrated Lime?

Thank you!

 

[pierreick]

Hi, my experience with milk of lime in soda ash plant is Carbon steel.I've spent 10 years in operation.
Pierre

 

[Andrew ONeill]

I've got plenty of hydrated lime piping that's 20 years old and is carbon steel, no signs of corrosion.
Erosion is a separate issue, more related to it being a slurry than a corrosion issue. Will often see hardened steel (usually stainless) around control valves to manage erosion issues.


Andrew O'Neill
Specialist Mechanical Engineer
Australia

 

[MJCronin]

"but a spec. I'm reading convinces me I need Stainless" .... Hmmmmmmmmm...

Very mysterious, very ... No sense in posting copies or excerpts or any other references to this elusive Third World "tribal knowledge"

My experience with these systems involves sometimes specifying an increased wall thickness (schedule 80 ?) AND/OR

... limiting the design flowrate to something reasonable by selecting the correct pipe diameter ... !!!

As stated above, erosion can be a significant issue .... if the pipe diameter is too small ...

MJCronin
Sr. Process Engineer

 

[EdStainless]

There are steels that will hold up to erosion better than others.
I haven't had to do a slurry job in decades so I don't recall the details.
In many services a little bit of Cr (0.2%) is enough to give much better performance.
Double check your velocities.
Make sure that fittings and transitions are all designed to minimize turbulence.
Use heavier walls.
The only mild caustic systems that I have seen in SS involved high purity products.


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P.E. Metallurgy, consulting work welcomed

 

[bimr]

The traditional material for this is carbon steel. Lime solution is not going to cause corrosion. The lime tanks are generally steel as well. You are more likely to have corrosion on the exterior of the pipe instead of the interior.

 

[Dhurjati Sen]

You need to carry out PWHT of the carbon steel weld joints.
Is that the reason which drew you towards SS ?

DHURJATI SEN
Kolkata, India