Taco Diaphragm Expansion Tanks

Taco Diaphragm Expansion Tanks for Hydronic Heating, Chilled Water, Commercial HVAC, and Industrial Pressure Control

ASME Expansion Tanks for Managing Thermal Expansion in Closed-Loop Hydronic Systems

Taco Diaphragm Expansion Tanks are designed to control pressure in closed-loop hydronic systems by absorbing expanded fluid volume as system temperature changes. These tanks are commonly used in commercial, institutional, and industrial HVAC applications where stable system pressure, reliable operation, and long-term equipment protection are important.

Diaphragm expansion tanks use a flexible diaphragm to permanently separate system water from the air charge inside the tank. As water expands, it enters the upper tank volume and deflects the diaphragm downward, while the air pre-charge remains captive in the lower tank volume. This separation helps reduce air absorption into the system water and helps prevent problems such as waterlogged tanks, air-bound terminal units, inefficient balancing, corrosion, and pump cavitation.

Taco CX Series Expansion Tanks are designed, constructed, and tested to ASME Section VIII, Division 1 requirements, making them suitable for demanding commercial hydronic applications. They are designed for smaller heating installations and many chilled water applications where smaller air volumes and expanded fluid volumes are required. Standard diaphragm models are rated for 125 PSIG working pressure.

Features

• Diaphragm expansion tank design for closed-loop hydronic systems
• Helps control pressure caused by thermal expansion
• Designed for commercial, institutional, and industrial HVAC applications
• Suitable for smaller heating installations and many chilled water systems
• Flexible diaphragm permanently separates air and system water
• Captive air charge helps maintain stable system pressure
• Helps reduce the risk of waterlogged expansion tanks
• Helps limit air absorption into system water
• Supports improved hydronic balancing and system performance
• Helps reduce corrosion, air-bound terminal units, and pump cavitation
• ASME Section VIII, Division 1 design, construction, and testing
• Standard diaphragm working pressure: 125 PSIG / 862 kPa
• Computerized selection tools help match the expansion tank to application requirements

Applications

• Commercial HVAC systems
• Institutional hydronic systems
• Industrial heating and cooling systems
• Closed-loop hydronic heating
• Chilled water systems
• Boiler systems
• Mechanical room pressure control
• Thermal expansion control
• Smaller heating installations
• Hydronic system air and water separation support