Weld Gas Standard

Yes there is a relationship between wire consumption and gas used....so it depends on the size of the weld how much wire you will use and how much gas you will use...so you need to calculate those...

..."Pounds of welding wire needed = (weight of weld metal per foot) x (feet of weld for job)

Sample Calculation #1

Pounds of welding wire needed for 5,000 ft of ¼ in fillet weld with flat weld profile (using values from Table 1).
Pounds of solid welding wire needed = (0.129 lb/ft) x (5000 ft) ÷ 0.85 = 645 lb of solid wire
Pounds of cored welding wire needed = (0.129 lb/ft) x (5000 ft) = 759 lb of solid wire

Shielding gas use can be calculated based on the flow rate (SCFH) used during production and the hours of welding needed to complete the job as follows:

Cubic feet of gas needed = (flow rate SCFH) x (hours of welding)

Sample Calculation #2

Cubic feet of shielding gas needed = (40 SCFH) x (100 hours of welding) = 4,000 CF

A typical “E” size cylinder of 75Ar/25CO2 shielding gas contains a little over 300 cu ft of gas. Therefore, you need to purchase about 13 gas cylinders for the welding job. The trick is to figure out how many welding hours are in a job. This is best calculated by using deposition rate:

Deposition Rate (lb/hr) = 13.1 x (wire diameter)2 x (wire feed speed) x (efficiency)
— Wire diameter in inches (in)
— Wire feed speed in inches per minute (in/min)
— Efficiency (1.0 for solid wire, 0.85 for cored wire
— This calculation is for steel only

Example: Wire diameter = 0.045 in (1.2 mm) solid wire, wire feed speed = 300 in/min
Deposition rate = 13.1 x (0.045)2 x (300) x (1.0) = 7.96 lb/hr

Cubic feet of shielding gas needed for 5,000 ft of ¼ in fillet weld using 0.45 in solid wire, at a deposition rate = 7.96 lbs/hr and a typical shielding gas flow rate of 40 SCFH.

From the first calculation, we know that we need 645 lb of solid wire for 5,000 ft of 1/4 in weld, therefore:

Hours of welding for the job = 645 lb ÷ 7.96 lb/hr = 81 hours of welding

Cubic feet of shielding gas needed = (40 SCFH) x (81 hours of welding) = 3240 CF

You will need to plan for about eleven E-sized shielding gas cylinders for this welding job. Again, the type of shielding gas mix (75Ar/25CO2, 100 percent CO2 etc.) determines the cost of gas as well as the packaging. Knowing how many cubic feet of shielding gas will help you get the best price and service from your gas distributor."...

https://www.fabricatingandmetalworking.com/2010/10/how-much-wire-how-much-gas/