Rotary valve core materials for filling machines 1

[niall68]

We manufacture piston fillers for filling all sorts of liquids products. We currently specify Waukesha metal 88 as the core and stainless steel T316L as the body (cast). What other materials would be a good alternative for the core?

Things to consider....
machining characteristics, Dimensional stabitity, grinding tapers to a fine tolerance
Wear resistance to abrasive liquids
Similar rate of thermal expansion to S/steel to avoid binding filling hot products.
Resistance to chemical attack, CIP fluids etc...
Cost..

We have tried, Dairy metal (has copper in it), some plastics like PEEK, Acetal, PTFE..

 

[gerhardl]

A typical cost/benifit question, and unable to be answered without knowing much more.

Some leading questions:

1. Why change? Price of material only, wanting to earn more?

2. If yes: upping the price of the product radically, selling on cost/lifetime argumentation? (What can the market bear?)

3. If no price compensation possible, searching cheaper and better material: better include re-thinking of the whole contraption, other material only will probably not contribute very much, and you have to include cost of retooling, re-establish and readministration of the fabrication and marketing side.