Head vented loop location

[turbulicity]

I currently have a vented loop between the seacock and hand pump. I read recommendations that it should be between the hand pump and the bowl. Can anybody weigh in on this and explain why?

[SVCarolena]

If it is between the seacock and pump, you run the risk of the pump pulling air in through the vent when you are trying to pump water. If it is between the pump and bowl, this won't happen. Raritan addresses this in their install manuals (available online). The vent should have a one way valve in it so that it only allows air in, but will not allow water out, so no worries about water being pushed out the vent. Hope this helps.

[turbulicity]

Yep, it makes sense. Thanks for the explanation. For now, the hand pump seems to be functioning properly and from what I understand, the current setup is not detrimental to siphoning protection but only to the pump function. So I can push this to lower priority.