Ball valves by design are NOT well suited for this type of dirty environment....IE: hole thru ball valve TRAPS crud/stuff when closing
Sliding disc valves are used for a reason when handling this type of effluent.
Check out valves on any 'honey wagon' --- 'septic tank pumper' unit.,,,,sliding gate valves
Not sure what has happened to yours......?
Mine (4 of them) are still functioning properly after 10+ yrs of repeated use.
3 are cable operated and 4th is straight handle.
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31