The OSO 21S hot water calorifier is available in eight storage capacities. The secondary water can either be heated by electric immersion heaters or indirect flow and return heating from a boiler. If required the calorifier can be supplied for connection to both heat sources. • Secondary pressure vessel factory pressure tested to 15 BAR. • Secondary maximum working pressure 10 BAR. • Primary pressure vessel factory pressure tested to 4 BAR. • Primary maximum working pressure 3 BAR (higher pressures upon request). • Double convex constructions eliminates dead zones in calorifier. • Outer primary water jacket design ensures even heat transfer. • All units manufactured to the international standard ISO/DIS 2694 (BS 5500). • All units supplied with 1" BSP secondary return as standard, larger sizes available upon request. OSO 21S SERIES SECONDARY HOT WATER PRIMARY THERMOMETER SECONDARY THERMOMETER PRIMARY FLOW AND EXPANSION CONNECTION MAINS COLD WATER INLET PRIMARY RETURN AND FILL POINT - builds water heaters for the future

- builds water heaters for the future Note: Primary Flow & Return Fittings are ND 80 Flanges Product & Order Code 21S 650 21S 1000 21S 1500 21S 2000 21S 3000 21S 5000 21S 7000 21S 10,000 529 809 1311 1611 2299 4129 6197 8847 100 110 270 310 400 730 1070 1120 95 106 172 180 260 303 377 476 2100 2150 2300 2400 2600 3000 4300 4970 780 1000 1200 1300 1500 1850 1950 1950 Domestic Capacity Litres Primary Capacity Litres Maximum KW Rating Dimensions Height Dia Dry Weight KG 350 450 700 750 1100 1850 2600 3450 Insulation Thickness mm 65 100 100 100 100 100 100 100 Connections BSP Female 1" 1" 11/2" 2"...