Right material selection

[vjr0512]

For transfer of Soldium Hypochlorite (12% solution) and FeCl3 (40% solution), which are the best material for the pump and its wetted parts including the Shaft. Some of the manufacturers are recommending Glass Fibre Reinforced Plastic....Shaft is of SS316..

The pumps are used to transfer the chemicals from bulk storage tank to the individual units day tanks.

Thanks to share your experience and preferably the suitable Pump manufacturers.

 

[ashtree]

Its difficult to give an absolute recommendation on this but 316 SS is probably unsatisfactory for both the ferric chloride and the sodium hypochlorite applications. But it will also depend on the pump design because there are pumps on the market that might have a SS shaft but the impeller and seal arrangement totally enclose the shaft.

Some good chemical transfer pumps are shaftless MAGDRIVE style.
I have used the following pumps.

http://www.iwakiamerica.com/products/MD.htm

But there are others out there as well.

A GRP pump body would be okay but there are also a number of other pumps that are of a "plastic" body type.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

 

[EdStainless]

316 would last for a few hours in this service at best.

The Hypo has known material solutions, for metals people would use a 6%Mo superaustenitic or a Ni-Mo-Cr alloy. Non-metals would be preferred if the temp and pressure would allow it.
The ferric chloride is almost impossible to handle with metals, at a price that anyone would be able to swallow.
For both of these you also need to be careful about which plastics you use, some won't cut it.

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P.E. Metallurgy, Plymouth Tube

 

[shvet2008]

What temperatures and pressures are? Can you use plastics or rubber lining? For example PP, PE or even PVDF, PTFE etc.It would be cheapest way - this pumps are cheap and reliable.

 

[moltenmetal]

Forget about alloys for this service. Corrosion immunity beats mere corrosion resistance every time.

Plastic materials, or plastic-lined, are your only hope. Solid plastic materials would be OK with the hypochlorite too but it's strongly aklaline so stay away from glass-reinforced plastics. Iwaki, March and Little Giant all make small magdrives without any internal metallic components, which are widely used for ferric chloride, pickling solutions and other corrosives at low pressures and modest temperatures.

If you need the pump to be very mechanically robust or to go to higher pressures, numerous manufacturers are making ETFE or PFA-lined ductile iron magdrive centrifugals which work well and last for a long time if you never run them dry. We had particularly good luck with Innomag which I believe Flowserve or one of the other monsters bought, but Durco (also a Flowserve product),

All plastic/ceramic air diaphragm pumps are the option if you need to pump dry.

 

[TenPenny]

The Goulds 3298 is a tefzel lined mag drive that would also be a reasonable choice.

I would simply avoid any metallic pump in this service.

 

[Compositepro]

You should consider a PTFE air-operated double diaphagm (AODD) pump if the pump is just for transfer service where energy efficiency is not critical. They are very corrosion resistant, have no dynamic seals exposed to the pumped fluid, and they are cheaper to buy and maintain.

 

[shvet2008]

to moltenmetal
Could you please share more information about glass-reinforced plastics, ETFE and PFA in chemical industry?

 

[moltenmetal]

Crane Resistoflex, DuPont Tefzel , Dow Derakane, Ashland Hetron...Google and read. Plastic thermo polymer and reinforced thermo sets, and linings, are widely used in the CPI. There are many services where metals and alloys are marginal at best and cheap plastics last 30+ yrs in service.