Need help finding water shutoffs needed to replace expansion tank ST-5

[GrowFigs]

Hello,

I am looking to replace an expansion tank that has failed and is discharging water from the air valve. I am not sure where to shut the water off as there are lots of valve handles in the system. I believe the system is a hydronic baseboard system that uses a boiler and storage tank. I see two shutoffs that are close to the expansion tank but another pipe leading into the tank does not have a valve close by. There is one about 15 ft away that is attached to 3 other pipes but I'm not sure if this is the one I need or not. I recently had problems with the T/P valve off the boiler leaking and discovered the failed expansion tank. Hoping that replacing it will solve the leaking issue.

In the first photo, you can see a shutoff vale in the top right and bottom right that both have feeds coming to or from the expansion tank. The pipe leading out to the left of the expansion tank leads to the second photo about 10-15ft away.

Any help is much appreciated! Thank you for your expertise!

 

[GrowFigs]

Figured it out! It was the lever in the second photo.

 

[breplum]

The best way to plumb an expansion tank is with its own shutoff isolation and a tee with hosebibb to depressurize. Code requires exp tank to be supported, cannot be left hanging.