This service valve links the expansion tank to the system or to the Service Center (#HGSC-MULTI) and allows you to isolate the expansion tank from the system pressure. While the tank is shut off from the system pressure, you can inspect it (verify pressure) or remove it for replacement without having to drain the system. Once this operation is over, re-open the valve and the system will get back to normal operation. It’s available in ½” MNPT × ½” FNPT and suits HGT-15, HGT-30, HGT-60M and HGT-60..