Summary for flapper valve finishing Discussion
Oxalic acid for flapper steel valves is not actually answered in the thread; the discussion instead shifts to how the valves should be finished. In the original 2007 question, Sunil Surve asks whether using oxalic acid in centrifugal finishing would affect performance properties such as compressive stress and fatigue life for 20C and 7C steel compressor valves. In a later 2012 follow-up, Venkat Surya asks what the correct finishing method is—vibro bowls, centrifugal, or something else—and what media is most common. The only direct guidance comes from the editor’s reply, which says the choice depends on the desired surface finish, whether any post-treatment will follow, and what mass-finishing equipment is available. The editor adds that the media selection depends on those answers, so no single process or chemical is recommended in the thread.
2007
Dear Sir,
Flapper steel valves are manufactured from 20C & 7C grades of steel used in compressors. To achieve desired finish, these valves after punching are introduced to centrifugal finishing machines.
I want to use Oxalic Acid (as such) in the finishing process. May I know the effect of this chemical on flapper valve’s performance such as compressive stress, fatigue life etc.?
Regards,
Sunil Surve
Employee – Mumbai, Maharashtra, India
Q. What is the correct method to finish the flapper valves. Is it through Vibro bowls, centrifugal or anything else. What is the most common media used?
Venkat Surya
– Mumbai, India
April 11, 2012
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Ed. note: Please tell us why you ask, Venkat, as it always makes for more interesting and useful discussions :-)
A. Need to ask you some questions? What is the desired surface finish end result. Are you going to treat the surface finish after you achieve that result? Do you have any mass finishing equip.? Media will depend on these answers.
AF Kenton
retired business owner – Hatboro, Pennsylvania
April 12, 2012