66 GAL FLOOR HYD EXP TANK

Product description

Zilmet ZHT250 Hydronic Expansion Tank
This is a 66-gallon diaphragm expansion tank designed to manage thermal expansion in large closed-loop heating systems.

Key specifications

• Type: Hydronic expansion tank (boiler/heating systems)
• Capacity: 66 gallons
• Connection size: 3/4" NPT
• Max pressure: ~60–90 PSI (varies by configuration)
• Max temperature: 210°F
• Material: Carbon steel shell with internal rubber diaphragm (SBR)
• Precharge: Typically ~12 PSI
• Orientation: Vertical floor-mounted tank with base

What it does

In large hydronic systems (boilers, radiant heating, district heating loops), water expands significantly when heated. The ZHT250:

• absorbs large volume expansion
• stabilizes system pressure
• prevents pressure relief valve discharge
• protects boilers, pumps, and piping from pressure spikes

Where it’s used

• Commercial boiler plants
• Large multifamily buildings
• Schools, industrial hydronic systems
• Large radiant heating networks