Aluminum-Bronze Vs. 316 Stainless Steel - Pump Material

[HalliburtonEngineer]

I will be pumping 3 different fluids, portable water, 1-10% Sodium Chloride brine and 1% Sodium Carbonate Alkaline (pH ~ 11) fluids. What material is best to use for the pump Aluminum-Bronze or 316 Stainless Steel?

My main problem is iron (Fe2+ and Fe3+), basically rust is getting into my fluid stream from our current carbon steel pumps. Although only 1-2 ppm, I need 0 (zero) iron in the water.

 

[Artisi]

I would probably go for Stainless as it is usually more readily available from pump manufacturers. If 300 series SS is not considered as Ok you could try Cd4-MCu, hard and ideal in brine etc.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[HalliburtonEngineer]

I would also think that 316SS would be good enough, but the vendor is recommending Aluminum-Bronze. I am just a bit concerned if the Aluminum-Bronze will work for high pH fluids.

 

[Artisi]

Why is the vendor recommending Al-Brz is there any price advantage for them and will they guarantee the material selection?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[TenPenny]

With a pH of 11, I'd lean more toward 316ss or a duplex stainless.

 

[micalbrch]

In general I agree with all others and lean more towards 316 SS as it is more suitable for NaCl and NaCo3 than Aluminum Bronze. But the concentrations are low and 316 SS still contains iron. What if the pump stands for a few days, especially if not completely filled? Alumium Bronze is free of iron and should work well with both solutions at given concentrations. But Artisi is right, the manufacturer knows your concerns (hopefully) and they must guarantee the manterial resistance.

 

[TenPenny]

I would be surprised if the manufacturer will guarantee the material. Typically, the pump company will leave it up to the end user to decide what material to use.

 

[Artisi]

TenPenny, I agree but they are insisting that Al/Brz is used so they should take responsibilty.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[pumpman50]

Dependant on the pressures and flow required why not go for a non metallic pump or one with an epoxy based coating on all wetted surfaces. Certainly much more cheaper than a duplex alloy.