Storage Calorifiers

We offer Calorifiers and Cylinders in accordance with the British Standard 853 or to commercial standards in sizes ranging from 190ltrs to in excess 4000ltrs.

The shells can be manufactured in copper, stainless steel or mild steel with either a copper lining or galvanised finish with the units being suitable for any primary medium or working pressure.

Our coded fabricators can manufacture to suit your specific requirements and site restrictions.

Also available are semi-storage high output, see Maximisers and Plate Heat Exchangers and non-storage calorifiers (below), package systems, mild steel buffer vessels, thermal storage and fully engineered skid packages all suitable for steam, HTHW, MTHW, and LTHW to BS853, BS5500 and ASME and ASME 8

calorifier example
Capacity Height Diameter Base
440 1800 600 +100
550 1700 675 +100
700 1750 750 +100
800 1950 750 +100
900 2000 800 +100
1000 2200 800 +100
1000 1950 850 +100
1200 2100 900 +100
1350 2350 900 +100
Capacity Height Diameter Base
1500 1950 1050 +150
1800 2300 1050 +150
2000 2500 1050 +150
2300 2400 1150 +150
2500 2450 1200 +150
3000 2950 1200 +150
3500 2700 1350 +150
4000 3050 1350 +150
Max Capacity 15000 litres

Non Storage Calorifiers

The McCallum range of non-storage heating calorifiers have been designed to meet the requirements of today's environment and are suitable for water to water and steam to water applications. We also manufacture a range of semi-package units, fully-packaged units and condensate pumping sets.


The NSZ range have welded mild steel shells, cast iron chests and copper 'U' tubes. The shells, chests and the heater batteries are designed in accordance with BS 853 with extended surface integron tube for efficient and compact units. The tubes are expanded into steel tube plates under electronic control to ensure even expansion. Batteries are adequately supported to prevent tube vibration and in the larger sizes a roller is provided to assist withdrawal. In many cases the heaters are baffled for increased performance. Mild steel chests are used when the design pressure exceeds 10 bar, the primary inlet temperature exceeds 120°C or the size of primary connection necessitates it.

Points to remember when specifying non-storage heating calorifiers

  • Type of fixing - Vertical or Horizontal.
  • Duty required in kW or litres/sec.
  • Primary and secondary temperatures.
  • Steam conditions after the control valve.
  • Working head or test pressure on the secondary side.
  • Maximum working pressure on the primary side.
  • Details of connections and mountings.
  • Any special circumstances or regulations affecting the installation.

non storage calorifier example
condensate receiver