GAS WASTE PROBLEM:

Two recent publications quote knowledgeable welding authorities indicating the average user of MIG welding consumes from 2 1/2 to 6 times the amount of shielding gas they could or should use.  CHECK REFERENCES

Depending on the regulator/flowmeter or pipeline  pressure, the volume wasted can exceed 5 times the hose volume when measured at standard pressure and temperature.  For relatively short welds, the waste can easily exceed the amount used when welding.  Longer gas delivery hoses waste more gas.  CHECK REFERENCES.

However you need relatively high pressure to provide Automatic Flow Compensation.  That's why gas distribution systems are designed that way?  What more information on this feature?

A production example where this problem existed and was solved with a Gas Saver System is sited.  CHECK IT OUT.

A special small ID hose is used with the  patented Gas Saver System (GSS^TM)  that reduces waste by 75%.  Since gas velocity would still be excessive at the start, a restriction orifice is incorporated into the hose fitting at the feeder end.  The restriction orifice further reduces waste by approximately an additional 5%, for an overall reduction of 80%.  Sufficient extra gas is left to quickly purge the air from the torch and weld zone.  The surge restrictor size is selected to allow any normal gas flow setting. This  hose is custom extruded with a large OD and fiber reinforcement to meet the tough physical needs of the environment.  It can be stepped on without altering flow.  If you have a Miller, Lincoln, ESAB, or Hobart welder a simple prefitted system is available.  Just remove the existing hose and screw in the GSS.

Restriction orifices have been added at the wire feeder to reduce gas surge velocity.  Most of these are sized to restrict the flow to some maximum level but still allow the welder to adjust flow rates.  This does help with the weld start problem -however- the pressure still builds in the gas delivery hose to that in the pipeline or regulator when welding is stopped.  When welding is started most of the excess is wasted, it just takes longer for the waste to occur, perhaps several seconds making it less obvious!

If the orifice is added at the feeder and is sized to control flow, several problems exist. A production example of one of those problems, lack of extra gas at the start,  is detailed in Production Results.  CHECK IT OUT.   This problem will exist with any device controlling flow at the feeder.  Also if the orifice size is selected to allow only a small amount of gas flow and since it provides no extra gas at the start, welders frequently drill them out to get more flow.  However the smallest drill often available is 1/16 inches.  Sounds small enough, but on a 50 psi gas pipeline that produces 165 CFH gas flow!!

Low pressure devices have also been employed to reduce starting surge.  These can produce several problems depending how they are implemented.  Similar to the use of orifices, they may save only a small amount of waste.  Or they may not allow enough extra gas at the weld start to displace air that enters into the torch and cable when welding is stopped or to quickly displace air (with its combined moisture) in the weld start zone.  Perhaps the biggest problem with low pressure devices is they do not provide automatic compensation of flow rate inherent in higher pressure systems. Want to understand why high pressure regulator/flowmeters are "A Good Thing?"  CHECK IT OUT

How Does Automatic Flow Compensation Work?

Manufacturer of Low Pressure Device Even Warns of Possible Problems.  See  Published Information.

For Recommended Gas Delivery System for Optimum Performance-CLICK

The patented WA Technology GSS::

1. Has no moving parts to wear, repair or leak;

2. Has no pressures to set or knobs to adjust.  

3. Allows a small amount of extra gas flow at the weld start to quickly purge air (with its combined moisture) in the weld zone and air that enters the torch shielding gas cup, torch body and cable during weld stoppage.

4. Unique, patented design reduces gas waste due to start surge by about 80% while maintaining the gas pressure in the delivery hose. 

5. Maintaining the higher pressure retains the systems ability to automatically compensate for varying pressure drops in the delivery hose when inadvertently pinched, squeezed, bent, etc.  Pressure drops in the  torch due to conduit bending and spatter buildup in the front end are also automatically compensated to maintain the preset flow. That is a key reason regulator flow systems are designed to operate at these pressures from the time MIG and TIG welding were introduced in the 1950's!. 

6. The GSS is inexpensive, payback is measured in weeks. 

Saving Shielding Gas and Improving Weld Start Quality is Easy..

"JUST"