bronze aluminum stainless pump in LOX liquid oxygen 1

[kenymcmack]

Does anyone know much about these materials in a lox (liquid oxygen) atmosphere? We are currently having some issues with our lox pumps. They are typical centrifugal side suction and top discharge pumps. Our current arrangement has a cast aluminum case, cast stainless steel impeller, and stainless steel shaft. There has been some talk about going to bronze impellers.
1. From a materials viewpoint, are there any advantages/disadvantages for using a bronze impeller in lox?
2. Is the current setup a good configuration with the aluminum case and stainless impeller in a lox pump?
3. Are there any other concerns with anything related to this situation?

Thanks a bunch.

 

[iainuts]

Hi keny'. I work for a major industrial gas company and have spec'd out those types of pumps you're refering to.

We would never put a LOX pump into service with any aluminum parts, and especially not the entire housing. If we found that we'd purchased a distributor or some other existing equipment with a cast aluminum housing on a pump, we would shut it down instantly. I honestly don't think we'd even run it once it was discovered.

Aluminum is highly flammable in oxygen service. The only pumps we use are bronze housing, with bronze impeller. I believe they still have stainless shafts, but the parts which are likely to impact, the impeller and housing, are made from bronze so there is no risk of a fire.

We've even had a few stainless steel reciprocating pumps burn since stainless is flammable at slightly higher pressures (above about 500 psi give or take).

Hope that helps.

 

[dcasto]

Great info.