Spirotop auto air vents

[MARKtheCHEESE]

1. Has anyone experienced these air vents (spirotop auto air vent) being installed on gravity fed dhw pipes on large systems?
2. Has anyone experienced these valves drawing air in with a secondary return pump in line?

 

[Dotty]

1. No.

2. It would.

 

[Glenwils]

Use them all the time. Fitted 6 today. Never had any problems with them at all.