Is this type of plumbing vent acceptable?
Depends on your plumbing codes.
That’s a mechanical plumbing vent, similar to, but not the same as, an Air Admittance Valve (AAV). (Spring activated vs. negative air pressure)
Here, the only place a mechanical vent is allowed in in manufactured homes (previously referred to as mobile homes). Some locales, Chicago, Illinois and several other States don’t allow AAV or mechanical vents at all.
In approved locales, and following prescribed installation requirements, an AAV is generally allowed if there is at least one properly vented fixture installed in the home.
Ask your AHJ…its perfectly acceptable as I see it from Ohio
Probably gets plenty of air in the line at the gap between the top of the tail piece and the bottom of the sink ðŸ˜‰
Certified AAV are approved, such as Oatley
Correct. Even if allowed, the one pictured is improperly installed.
Yes, Improperly installed, no trap arm.