I have an older Kitchen Aid dishwasher that works great except for a bad drain check valve. I've checked both Kitchen Aid and Whirlpool, as well as local and web appliance parts suppliers, and all say the part in no longer available with no replacement. It'd be a shame to junk the dishwasher for want of a generic part like this. The original part is really simple with just a rubber flapper for a back flow preventer so you'd think there'd be some type of replacement option. The Kitchen Aid part number for the valve is AP2919715 and the corresponding Whirlpool part number is 4162920 (about $10). Any help would be greatly appreciated.

Thanks for the reply. Elevating the drain hose would solve part of the
problem but wouldn't keep the last of the dirty water that's been pumped out of the disherwasher and still in the hose from flowing back into the dishwasher. It appears to me that I still need some type of appropriate back flow preventer.