Hand crank pump for water filters

I’ve long thought (especially after pumping a couple gallons) that a crank-motion pump would be easier and faster than the typical linear-motion pump, even those that pump in both directions. I’d think that a filter pump would have to be more robust than small hobby pumps because of the considerable backpressure from the filter, which I’ve been told can be as high as 50 psi for really fine filter media.

Either one is better than the squeeze-bulb filter a hiking buddy once owned :-)

Yes, something with some gear reduction, giving some leverage for pressure and increasing the capacity per revolution. The hobby pumps are 1/4oz per revolution, which comes to something like 800 revs per liter– quite a workout.

a wee bit ‘o dimensional analysis reveals the following:

~33.8 oz/L x 4 revs/ oz = 135 revs per L

…still a workout. normal hiker pump-filters are typically 24-36 pumps per Liter, taking 1-2 minutes to pump a Liter, depending upon the pump (and stamina of the pumper).