First time post & not a plumber!
I'm looking for help with the installation position of an Oatey in-line vent. I've installed a sink pump system that pumps directly to the septic line in basement. The pump system requires a vent line. I couldn't easily attach the vent to the existing vent system in the house. I tried this Oatey in-line vent however the water in the sink does not drain with it installed. If I remove the the vent it flows as it should. I have the vent installed fairly high to the ceiling and thought maybe it needs to be lowered. The pump has a flow check valve and is hard piped to the existing drain. The sink has a trap as normal. I've attached a simple sketch of my situation and was hoping someone here could provide some assistance. Thank you in advance for any help.