Does this make sense? Water hammer arrester - no path?

[MarsellusWallace]

Hi all,

I'm installing a washing machine outlet box for the laundry in the basement and purchased an Oatey set (48202).. it comes with that box, and quarter turn ball valves with built-in water hammer arresters.

I just noticed, looking into the valve, that the water circuit to the arrester is blocked off when the valve is open.

Does this make sense? Or am I not seeing something?
Did they build in water hammer arresters just for closing the valve by hand and not for water hammer from the actual washing machine?

I've attached a pic, you can see inside, the ball valve only has two openings. When the valve is open, the ball inside blocks off the direction to the arrester, but when closed the water direction is from pex to arrester...

This makes absolutely no sense either way.. Were these arresters intended to dampen hammer from closing the valves by hand? Or are they scamming people with this? Lol, I could just close them slowly if that's the case.

If I'm not understanding this correctly, would appreciate learning about this further. There is 100% no path to the arrester when the valve is in the open position; I even used a thin wire to check

 

[John Gayewski]

Take the arrestor off. I'm sure you'll see it's made differently than you think. Why would they be "scamming" what do they have to gain from scamming?

 

[Sponsor]

 

[Fitter30]

Your only seeing 1/4 of the ball. Im sure the arrestor is in play.

 

[Reach4]

"Did they build in water hammer arresters just for closing the valve by hand and not for water hammer from the actual washing machine? "
No.