Auditing a flame brazing process

Expert Consultancy

As our name implies, Flame Application Services is involved in ACTIVITIES with FLAMES…but not just any process with flames.

Flames are used in many applications in all sectors of industry.

Flame Application Services is only involved in those specialized applications which utilize SMALL FLAMES and where the Flame impinges (i.e. touches) a material

A flame is a heat source….the purpose of the flame is to raise the temperature of the material it touches to a sufficiently high enough temperature to enable a process to be carried out…what is the process? And what type of flame is required?

One such process is Flame Brazing (often referred to as Torch brazing) ………

Brazing, is a time/temperature process where the flame is the source of the temperature. There are many other factors (apart from the nature and composition of the flame) that must be considered in order to carry out a flame brazing process successfully. (Please use this drop down menu for further information on how to Audit a flame brazing process)

Flame Application Services is solely owned and managed by Derek Davies BSc (Hons)  His Degree is in Industrial Natural Gas Engineering (Utilization) and was awarded by Salford University 1979 ( His thesis was: Special studies of  heat transfer from small working flames)

Since that time Derek has been closely involved with a multitude of flame heating applications resulting in:

  • 30yrs experience in flame applications.
  • Committee member and flame braze training provider for EABS  (European Association for Brazing and Soldering)
  • External Technical Consultant to Solvay Fluor GmbH….major global suppler of Nocolok® aluminium brazing Flux.
  • Consultancy, trouble shooting, process development, project management in the UK, Europe and USA
  • Equipment design, construction, supply and commissioning
  • Training


Brazing can broadly be classified into two main areas.

  • Brazing in an enclosure i.e. Furnace brazing either in a Vacuum furnace or under a reducing atmosphere (without flux), or Controlled Atmosphere Brazing CAB (under nitrogen with flux) when aluminium is to be brazed
  • In air brazing i.e. brazing with a flux in open air by FLAME, Induction or Resistance

What is common to all these processes is:

  • The need to understand the technical detail of each type of application method,
  • The vital importance of collecting process data and
  • Tearning how to interpret the data that has been gathered.

Derek has been extensively involved in flame brazing for 30 years, and has delivered many theoretical, and practical training sessions, together with practical troubleshooting in connection with many different flame-brazing applications on machine designs of various complexity from a large number of different “flame brazing equipment manufacturers” from all over the world!

During such projects Derek has been asked many time “what are the most common problems associated with the flame brazing process?”

The answer given is always the same:……PEOPLE……!

Firstly they tend not to fully understanding the basic rules, and this inevitably leads to their inability to apply them to best effect for their application.

The key aspects of flame brazing PROCESS always include:

  1. Service condition and environment…
    1. what is the product being brazed,
    2. what is it to be used for and
    3. where will it be used ?
  2. Material selected……
    1. which materials are to be brazed?
  3. Which joint design will be used, and what are the dimensional tolerances of the components?
  4. Which alloy and flux is the most appropriate for the assembly?
  5. Which fuel-gas is to be used, and will it be mixed with air or oxygen?
  6. Which type of heating equipment is required or is currently being used?……
  7. Which level of flame process complexity on the scale of 0 to 10 will be required?
  8. Will automatic temperature control be required?


People make decisions….. but they never intentionally set out to make wrong decisions!

At the time they need to make some initial choices concerning the way forward they might not have all the data necessary to make the correct decision.

The different stages of a project can be:


It is very common for a number of different people to make a particular decision as a project moves from concept through to the manufacturing stage.

Unfortunately, when troubleshooting ‘problems’, on arrival in the workshop one almost always finds that the project is already at an advanced stage, and that a number of vital decisions have already been made.

In such a situation the wise man will start collating process data. With that to hand it often shows what is wrong and why it has reached this situation! It then becomes much easier to develop a solution to the problem being experienced.

Selection of Flame brazing equipment

All flame brazing processes and equipment lies somewhere on the simple complexity scale between  0-10. ie:

0…….simple manual flame process using a hand held torch
1…….simple bench mounted flames
2-3….simple small shuttle brazing machines.
4-5….more complex small shuttle machines
6-8….more complex rotary or in-line machines
8-10…extremely complex automatic machines

Readers can be certain that the flame brazing process that they are currently using will lie somewhere on the above scale.  If they are seeking to improve the existing process they will be looking to achieve one of for the following objectives.

  • Improve Productivity
  • Reduce costs
  • Improve quality
  • Increase output
  • De-skill operation

If you have a new project where you believe that flame-brazing might be the way forward you will be interested to know when you achieve any of the above end-results you automatically achieve all of the others!

However, if you are already flame-brazing it might be necessary for you to move to a higher position on the Process Complexity Scale in order to achieve your objective.

In either case Flame Applications Services will be able to help you!

Today, with the use of digital photography and e-mail, it is very easy for Flame Application Services to make an initial assessment of your needs. Our wide experience of flame brazing allows us to undertake an initial ‘audit’ of your current procedures with you only incurring the cost of sending the data to us!

When we receive your data we will respond with impartial comments and advice on what actions we believe that you have to take in order to achieve the results that you need.

Contact us today and start saving money!