VAREM EXTRAVAREM LR expansion vessel for heating systems 18 l, 3/4", 6 bar

VAREM EXTRAVAREM LR 18 L is a diaphragm expansion vessel designed for closed water-based heating systems. It compensates for the increase in heating-medium volume caused by rising temperature and helps maintain stable pressure within the heating system. EXTRAVAREM LR belongs to VAREM's dedicated heating expansion-vessel range.

The EXTRAVAREM LR uses a fixed membrane separating the heating water from the pressurised air chamber. As the heating medium warms and expands, the increased liquid volume enters the vessel; as the system cools, the liquid returns to the heating circuit. The 18-litre model uses a galvanised carbon-steel counterflange.

Nominal capacity is 18 litres, maximum working pressure is 6 bar, and the standard factory pre-charge is 1.5 bar. The heating-system connection is 3/4", while the manufacturer's specified dimensions are 270 × 415 mm.

The vessel is designed for water temperatures from -10 to +99 °C. VAREM's conformity documentation specifies PS 6 bar, test pressure PT 9 bar, standard pre-charge 1.5 bar and temperature limits of -10…+99 °C for the EXTRAVAREM LR 18 L model group.

VAREM does not recommend water/ethylene-glycol or water/propylene-glycol mixtures as the standard application for the EXTRAVAREM LR range. If glycol is used, the maximum permitted glycol concentration is 20% and the maximum fluid temperature is +70 °C. With water, operation is permitted up to +99 °C.

EXTRAVAREM LR is not suitable for potable water. It is specifically part of VAREM's heating range; potable-water applications require a vessel from a suitable sanitary-water range.

The vessel is finished in red. VAREM specifies a packaging volume of 0.034 m³ and a pallet quantity of 56 units for the 18-litre model.

Unlike the 5 L and 8 L EXTRAVAREM LR versions, for which CE marking is not applicable, the 18 L vessel is included in VAREM's CE/PED conformity documentation and is listed under EN 13831.

Technical information