Refrex® Multi Tube Bellows (MTB)

Insulcon Refrex(R) Multitube Bellows (MTB) are usually fabricated using high temperature resistant textiles (upto temperatures of 1370 degC or 2500 degF) to seal complex gaps in fired heater or furnace systems. Each MTB is specifically engineered to absorb the multi-axial movement of the tubes whilst still retaining a near perfect seal on the interface between the firebox and the external environment. Depending on the operating temperature, the MTB can be designed and manufactured either filled with ceramic fiber blanket or loose ceramic bulk fiber for adequate heat insulation.

Features of Multi Tube Bellows (MTBs)

  • Made out of Refrex® fabric and resistant to high temperatures of upto 1370
  • Flexible
  • Custom-made
  • Applied in the refining and petro(chemical) industries
  • Can be opened for maintenance and re-installed thereafter.
  • Seals all kind of tube penetrations in roofs, floors ,walls for all types of process heaters and reformer furnaces
  • Weather resistant
  • Pre-fabricated

Multi Tube Bellows vs Conventional Method !

Conventional way utilizes sliding plates, an insulation padding or an insulation blanket around the tube.

These methods are ineffective at sealing off the flow of air through and around the heater. In some cases, “seals” block only 10% of the ingressing air.

Air Ingress

Multi Tube Bellows

A flexible tubing-passing sealing system to block all the air ingress.

Before and After Instalation of MTB

How MTBs are designed and installed?

Firstly, some details are taken into account such as :

  • Process temperature
  • Required cold face temperature
  • Diameter of tubes
  • Minimum and maximum movement of tubes

The data are then used to design & fabricate MTBs in our factory and shipped to our clients

Inner fabric of MTBs are installed first and then it is filled with refractory blanket or loose refractory bulk fiber , finally finished with the installation of the outer fabric.

* Depending on the requirements of the client, the fixation method can be varied from Custom fabricated steel plates to support the MTB onto the furnace plate, Separate (tube by tube) fixing bands, Refrex® tie-cords (fully inserted in the Refrex® fabric topside of the MTBs).

Installation of MTB

Key Benefits

  • Significant reduction of cold air ingress resulting in improved furnace efficiency.
  • Withstand temperatures of up to 1370°C.
  • Allow unrestricted movement of the tubes while maintaining complete seals.
  • Reduce the possibility of tube damage due to rapid quenching.
  • Block radiant heat loss.
  • Cost effective with very fast payback on investments.
  • Personnel safety enhancement.