SECOND
CAUSE OF WASTE: EXCESS GAS FLOW SETTINGS
We have often found gas
flowmeters with the ball pinned to the top of the flow tube. Our tests show
this can be a 150 Cubic Feet per Hour (CFH) gas flow rate.
This excess is not only wasteful but causes poor weld quality. The following is a quote from an
article published in Practical Welding Today by Kevin Lyttle, Manager
Welding R&D for Praxair which states; “In many instances production site
surveys (of fabricators using MIG and Cored Wire) determine that shielding
gas flow rates typically are set in excess of 50 CFH. This can contribute
to poor weld quality as atmospheric gases are drawn into the arc zone
because of excess gas turbulence. Optimized flow enhances quality and
reduces shielding gas usage.” (Reference 3 Below)
Another article by The
Welding Institute in Cambridge England qualified the maximum flow rates in a
MIG torch before excess turbulence was created. For the most common
5/8 inch ID MIG torch nozzle, 48 CFH is the maximum flow rate before
turbulence is encountered. For those using low current MIG welders
employing the typical ˝ inch ID MIG torch nozzle (used by most small shops
and home users) will allow only a 37 CFH maximum flow before encountering
turbulence. (Reference 4 Below)
Research performed to see
if increased flow could improve weld quality in a 5 MPH wind environment
yielded interesting results. This unpublished work showed that with a
standard 5/8 inch ID MIG torch nozzle, a 45 CFH shielding gas flow rate
produced less internal porosity than 65 CFH!
This
validates that turbulence created by the 65 CFH flow rate causes moisture
laden air to be sucked into the shielding gas stream and is counter
productive. Unfortunately many welders think "if some shielding
gas is good more must be better."
We find most folks selling shielding gas
either; 1)
don’t understand the excess
flow problem or 2) don’t communicate it or
that the start gas surge is a key
reason for shielding gas waste and
weld problems. Recently when discussing our
GSS with an engineer at a plant making
highway trailers he said his gas supplier just checked their flow rates and
the 100 CFH set by flow control orifices at their pipeline gas drops was
fine! As my 9 year old granddaughter would say, “Like Duh!”
THE SOLUTION: If you’re using flowmeters on
cylinders or on a pipeline gas supply a patent pending lock (photo left) is available
that allows the maximum flow rate to be set and locked.
See Details.
An
article in Trailer Body Builders magazine quotes a representative from
Praxair, a leading producer and marketer of shielding gases, indicating
their findings show the average fabricator using MIG welding consumes 6
times the amount of gas theoretically needed. Stated as a percentage, 83%
of the shielding gas used is wasted! (Reference
1 Below)
THE
SOLUTION: The use of our recently patented Gas Saver System (
