Wetted Parts for Oil/Water Slurry

[wardens355]

A truck wash down facility at an oil extraction operation is using rotary lobe pumps to move oil/water/silty slurry to an oil/water separator. The oil and chloride content is unknown since operations have not started yet, but there will be salty water used for wash down. Currently, the wetted parts of the pump are going to be cast iron (about 1/2 price of stainless steel), and the lobes will be Viton. Operating at 450 gpm, 25 psi, using rotary lobe over centrifugal to avoid emulsification. Has anyone selected pumps for similar operations? And should significant deterioration be expected with cast iron?

 

[micalbrch]

I have no experience with such a set-up but with pump materials and salty water. I would not use cast iron for chlordie contents > 500 ppm at ambient temperature and > 200 ppm at more than 40 °C.

 

[Artisi]

or for the solids (grit, sand etc) coming off the trucks.

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.)

 

[1gibson]

Stainless for double the price sounds like a pretty good deal, unless you want to purchase a complete spare pump in cast iron up front. Even then you have to store it, and it is not a great long term plan. Aftermarket prices will eat you alive if you just buy one in cast iron, then try to get replacement parts.

 

[wardens355]

We have told the client that we do not recommend cast iron (they are also using PVC piping - we also told them we do not recommend this). Even so, client is going with the cheaper materials and treat as a potential throwaway. The information is good to know for future projects however, thanks for the responses.

 

[bimr]

Just going to stainless may not solve the problem. High chlorides or the grit may attack stainless.

Have you considered separating out the soils and oil prior to pumping. Huber makes grit separating systems that will accomplish that.

http://www.huber.de/fileadmin/01_Pr..._behandlung/sandabscheidung_uebersicht_en.pdf

http://www.huber.de/fileadmin/08_HUBER_Report/01_nach_Produkten/99_Industrie/Sand_Daqing_e.pdf

 

[psv1990]

Based on the price and wear the lobe pump you will see, you may want to consider a submersible pump designed for your application. Wier offers the pump that can be see at the following link.

[URL unfurl="true"]http://www.weirpowerindustrial.com/products__services/pump_products/screw_centrifugal_pumps/wemco-hidrostal_prerostal_pump.aspx?tab=features[/url]

You can use this pump to pump all your sludge from your pit to your oil/grit to your seperator system.

 

[bimr]

Submersibles are generally less efficient and less reliable, which will make your present problems (material of constructions) worse.

 

[Artisi]

why is everyone worrying, the OP has already stated the clients intentions.

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.)