Author Topic: Flapper valve design advice needed  (Read 1847 times)

Offline picclock

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Flapper valve design advice needed
« on: November 08, 2012, 02:11:22 PM »
Hi All

I'm making a pump which will pump both fluid and gas. Whilst the outlet valve is sorted I am struggling a bit with the inlet valve. The speed of the pump is 240 rpm or less so the valve has to be quick acting (low mass). My current thought is some viton rubber sheet fixed to the cylinder head and two leaf type springs made from old feeler gauge attached to some aluminium sheet (or fibreglass) which is the valve. Sorry terrible with words - see sketch. Now my real issue is how long will the feeler gauge last under flexing like this - is there an alternative better material ?. Other design alternatives are a free floating valve held in position with a couple of posts or using just a strip of supported viton (stick stiffener on top) as the hinge over the inlet hole - not sure how long the viton will last due to the flexing. The pump pressures are very low - around 10 psi.

Any help much appreciated.

Best Regards


Engaged in the art of turning large pieces of useful material into ever smaller pieces of (s)crap. (Ferndown, Dorset)

Offline Raggle

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Re: Flapper valve design advice needed
« Reply #1 on: November 08, 2012, 03:27:29 PM »
Here's a good description of a 2-stroke engine reed valve. Frequency can be very high but the important part is the "keeper" which limits the amount of opening. Of course, you only need one in your application instead of the four grouped here.

Hope it helps

still turning handles  -  usually the wrong way