VPl& CCfolwer thanks for the comments. I was thinking of a resilient wedge knife GV. I have to replace an existing large pump. The dry well is very old and small. I would have preferred to use a plug valve and a check valve on the pump discharge, or, atleast a regular resilent type gate valve and check valve. Unfortunately there is no room for these. So my last hope is a resilient wedge knife gate valve (KGV), and to prevent backflow, a pump controlled actuator for the KGV if this option is available. Do you two think that the last choice is possible? This is a sewage application. So ball or BFV is not possible.