check valves

Hi Alan

I don't know what the ball diameter should be, but I would think 1.5 x the seat hole diameter would be ok.

It strikes me that the area of the hole diameter D and radius R is: Pi x R x R and the area of port opened by ball lift of L is Pi x D x L

We would want these to be equal or perhaps the lift to be slightly greater for max flow.

Pi is on both sides and D = 2 x R

so the Hole area, R squared = the lift area, which is 2R x L

R x R = 2R x L

divide both sides by 2R

L = R squared / 2R

substituting D for 2R

L = R squared / D

Anyone have any better thoughts?

Steve (Sheffield)

This any help?

Don't ask me how though....

Michael

In message , Steve writes

I have just looked at a couple of published designs of boiler back-head clacks (LBSC & Don Young) who seem to favour a ball:seat ratio nearer to

Whether ball movement is free or closure is spring assisted, it would seem obvious that to ensure fast and clean action the range of movement of the ball in any direction must not be much greater than the minimum required for free flow. Thus in addition to constricting the lift, the diameter of the horizontal space in which the ball is lifting is also important.

Steve You have done all the work but I think you can continue and say L= R squared /2R and cancel out the R's to L= R/2 or D/4 which gives the lift to equal the hole dia. Alan

this is what i built for waste oil burner pump

this is one of them outlet...the ones on the inlet are built slightly reversed

sorry cant take the pump apart for pics as its in use ...

the top half threads into the lower half.

o-ring fitted to the little plunger that seats on the chamfer at the end of the drilling ..

not much restriction in this design

the guide on the plunger is x-section ...so you get good flow ..

squiggly thing is spring.

not quite to scale ...and drawn quickly

sorry if this post appears not with the others ...as goggle is down and this was the only way to post .

all the best.mark