Indirect Storage Cylinders


GMS Indirect Cylinder

Indirect cylinders manufactured by GMS Thermal Products can be supplied with two types of internal coil, helical and a fixed tube heater.

Helical Coil Cylinders

An indirect cylinder with a helical coil generally has a ‘bolted top’, which is a removable lid to enable the coil to be fitted and removed. These coils are generally suitable for pressures up to 5 BarG and primary temperatures up to 120°C. The coils are also suitable for applications with a steam primary medium, but a calorifier with a removable U-tube battery is a better option.

Fixed Coil Cylinders

GMS supply an indirect cylinder with a fixed copper coil heater. Manufactured from copper integron tube, the heater has an inlet header and an outlet header, with the heat exchange tubes between the headers. The size of the header increases in line with the increase in size of the primary system connections. The size and quantity of exchanger tubes increases in line with the duty required. The coils are suitable for pressures up to 3 BarG and primary temperatures up to 82°C.

GMS manufacture indirect cylinders using the following standard materials:

  • Solid Copper
  • Galvanised Steel
  • Stainless Steel

Should you require more information on our range of indirect cylinders please contact us.

Information Pages


     Primary Heat Source

     Some System Considerations

     Ancillary Items

     Thermal Insulation

     Design Standards

     Unvented Packages

Technical Documentation

     Download Data Book

     Download O&M Manual

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