Is This a Check Valve?

[Baumgrenze]

I did a quick Google image search for 1/2" brass check valves and found nothing like this. It was part of an installation of a hot water recirculation system with a dedicated return. It was performed in 2010. I believe at least 2 plumbers working for different sub-contractors (general contractor's decision) worked in this area. I am trying carefully to sort out what I have installed and do not recognize this device. In the hard to reach 'back view' (iPhone selfie mode) I read 250 CWP, above that Si, and above that I see an arrow, suggesting a directional device like a check valve. On the more accessible side I read 1/2, and above that 2 interlocking rings, and above that the letter A.

I apologize for keeping this question separate, but it is easier for me (and perhaps others to come) to follow the thread of responses.

thanks
baumgrenze

 

[Terry]

That's a spring check. Different than a swing check but used the same way.

 

[Sponsor]

 

[Baumgrenze]

Thank you, Terry, for the confirmation, with detail, and also thank you for the forum!

baumgrenze