brass valve brass valve body

[va4ngo]

Hello all,
I have a very basic question regarding a works in progress.

I am building "An unusual steam engine" from plans in Live steam magazina circa 1975 and the drawings call for a brass valve body 1/4" I.D, and a sliding valve with material not specified.

I have made the valve also from brass. Should I have used steel and not brass?
Your help would be appreciated

Regards
Phil

 

[Fred]

Hello Phil,

in a display model which is run only occasionally, you will most likely get away with pairing brass with brass for a sliding valve. Unless you are planning to run the engine on steam for extended periods of time, brass/brass should be fine, particularly when lubricated.

As far as the theory goes, steel/brass or steel/bronze would be better choices. Take a look at a chart of friction coefficients, e.g. http://www.engineeringtoolbox.com/friction-coefficients-d_778.html

Have fun,

Fred

 

[va4ngo]

Thanks Fred,
That puts me a little more at ease. Fortunately the sliding valve is a very simple turning excercise and if I intend to run with steam (I haven't in th epast) I will make a new valve. I am not one to enjoy doing a job twice.

Good info in that reference to frictions of various materials.

Regards
Phil