Black Water Valve Won't Close

I had the same issue a while back the valve would not close all the way causing the liquid to drain out (grey tank open) and leaving the solids. I took the MH to a repair facility (Charlie's in Utah) and they hooked up a macerator pump to the tank and after filling up the tank the macerator was used. That worked for about 1 minute till the pump froze from the so called flushable wipes jamming up blades (stainless steel) of the pump. The fix was to get the tank drained and then remove the valve and related plumbing to access the black tank where many of the so called flushable wipes were removed. It seems that one of the wipes got caught on a rough piece of plastic or something causing the valve not to close. Shoot three or four hundred dollars later I was a real happy camper :M

JimR