Expansion Vessel VAREM EXPANSION VESSELS 5-40 L HOOK – 5–40 L capacity, hooked mounting

VAREM EXPANSION VESSELS 5-40 L HOOK is a pressure expansion vessel intended for closed heating and domestic water systems with capacities from 5 to 40 litres. The vessel features a hooked mounting that enables secure attachment to walls or frames and is designed to absorb pressure fluctuations in the circuit. It reduces pump cycling, helps maintain stable system pressure and provides protection against overpressure in boilers, water heaters and circulation loops.

Advantages

The hooked mounting simplifies installation in confined plant rooms or on boiler frames without additional brackets. A bladder-type internal separator ensures separation between system fluid and the pre-charged gas chamber, maintaining consistent performance over repeated cycles. The range covers multiple capacities between 5 and 40 litres so installers can select an appropriately sized vessel to limit waterlogging and extend pump life.

Suitable for

• Closed central heating systems
• Domestic hot water systems (indirect water heaters)
• Boiler and combi boiler pressure control
• Circulation and recirculation loops
• Small commercial or residential hydronic installations

Key specifications

• Capacity range: 5–40 litres
• Mounting type: hooked wall/frame mounting
• Internal design: bladder/separator style vessel
• Function: absorbs pressure fluctuations and reduces pump cycling
• Application: closed heating and domestic water circuits

How to use

Mount the expansion vessel using the integrated hook to a suitable structural point that can safely carry the filled weight. Connect the vessel to the system at the designated pressure line using appropriate fittings and ensure the connection is leak-tight. Pre-charge pressure should be set to match system static pressure; check and adjust with a pressure gauge and air valve before commissioning. During system start-up, verify that the vessel accepts and releases fluid as pressure varies and inspect connections for proper sealing.

Usage recommendations

Check the pre-charge pressure periodically and top up or bleed the vessel according to the system manufacturer’s guidelines. Select the vessel capacity based on system volume and maximum allowable pressure variation to minimise waterlogging and excessive pump cycling. During routine maintenance, inspect the bladder for signs of deterioration and replace the vessel if leaks or loss of pre-charge are detected.