Hydronic expansion tank assembly

A plumbing assembly for a hydronic system with an expansion tank, comprising:

• an isolation mounting arm having a fluid passageway with a first end portion, a second end portion, and a medial portion located between said first end portion and said second end portions, including:
• a mounting bracket at the terminal end of said first end portion;
• a first tee located in said first end portion, said first tee including oppositely disposed first and second ports;
• a third port located in the medial section;
• a drain port located at the terminal end of said second end portion;
• a second tee located in said second end portion, said second tee including oppositely disposed fourth and fifth ports;
• a first valve member coupled to said first port;
• a second valve member coupled to said second port;
• a third valve member adjacent to said drain port;
• a port adaptor coupled to said fifth port;
• a locking joint coupled to said port adaptor;
• and
• a locking nut coupled to said locking joint.

A hydronic system, comprising:

• an incoming fluid supply line;
• a supply line for a hydronic system;
• an isolation mounting arm having a fluid passageway with a first end portion, a second end portion, and a medial portion located between said first end portion and said second end portion, including:
• a first tee located in said first end portion, said first tee including a first port coupled to said supply line for the hydronic system and an oppositely disposed second port coupled to said incoming fluid supply line;
• a third port located in the medial portion;
• a drain port located at the end of said second end portion;
• a second tee located in said second end portion, said second tee including oppositely disposed fourth and fifth ports;
• a first valve member coupled to said first port;
• a second valve member coupled to said second port;
• a third valve member adjacent to said drain port;
• and
• an expansion tank coupled to a union adaptor that is coupled to said fifth port.