Calculating for breather cap

[shears]

I am trying to figure out what size of breather cap I need for a tank that holds 105 gallons of hydraulic oil. I have the forumula for that, but how do I calc. the gpm? What else do I need to know?

Thanks

 

[gerhardl]

What formula? Breather cap for what? (For us non-native english speaking)

 

[hydtools]

What is your concern about the breather cap? What do you want to calculate? Select a cap for the size of the filler neck.

See:

http://www.zinga.com/index.aspx?page=products&seriesid=92

Ted

 

[hydtools]

Or this:

http://www.lenzinc.com/index.cfm?template=catalog&form_product=210

Ted

 

[jbwick]

shears, what components are in your system? If it is pump > motor then you follow hydtools advice and get whatever fits. If you have large differential cylinders you need to calculate the return flow on retract and size accordingly. The second link hydtools posted has some scfm to gpm numbers for their filters. (1scfm ~ 7.5gpm)

 

[hydtools]

1 cu ft = 1728 cu in
1 gal oil = 231 cu in
1728/231 = 7.48

So, for every 7.48 gallons of oil in or out of the tank there is a change of 1 cubic foot of air. Neglecting compression, expansion or temperature change of the air. Close enough for estimating air movement due to oil volume change in an open tank.

Ted