Products / Twin Wall Flue
HT - Summary

HT - Summary | Technical | All


316 S/S Inner 304 Outer Rockwool Insulation.

Push fit, twin wall, insulated, stainless steel flue system for use on gas, oil and solid fuel appliances.

  • Available in sizes from 400 to 760  mm
  • This product is made to order
  • Maximum operating temperature 450 deg C
  • Standard finish is: Bright annealed stainless finish

  • 1 year manufacturer's warranty for all products installed and maintained in accordance with the installation and usage notes.

  • All products can be powder coated to any BS or RAL colour code

HT is suitable for use on the following applications:

HT Description:

  • Midtherm HT is designed for the commercial market serving gas, oil, solid and mutifuel installations, peat, wood and other biomass. Midtherm HT has a high temperature negative pressure. HT has a 0.5mm 316L 2B grade stainless steel inner liner with a welded seam and a 0.5mm 304 BA grade stainless steel outer casing with a welded seam. Insulation is 25mm/50mm high density mineral wool.

  • It is manufactured using the latest manufacturing and welding technology ensuring high quality and value for money. Lengths and fittings have a quick and easy to use socket and spigot jointing system. Locking bands are used to secure the joint on site.

Joint Type

Push fit socket and spigot type joint, to be installed with a locking band in place.

HT Installation and Usage Notes

All flue system installations, i.e. oil, gas, solid and multi fuel, should be carried out by a suitably qualified installer or Building Control Department permission must be granted.


For detailed installation guidelines please refer to:

  • The relevant Technical Information and Installation Instructions
  • Building Regulations
  • Planning Office
  • Appliance Manufacturers Operating and Maintenance Instructions
  • Relevant British Standards




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