|
|
Hi all.I'd like to know what's the correct way to calculate the cost of gases for oxy acetylene welding.We weld using L-Ag45Sn or AG104 rods. I know the price per kg of the rods and the weight for each individual rod, so that is one down. But I don't really know how to effectively calculate the cost of the gases. Could anyone please help?
Reply:If you look up the factory data for the tips, it should give the cfm for each tip. I know that I have seen and used that kind of data in the past. Of course, it would depend on whether or not the torch manufacturer publishes that information. So start wading through the factory data sheets and see if you can find cfm or liters per minute for the various tip sizes.Richard Originally Posted by Pitbull_RavenHi all.I'd like to know what's the correct way to calculate the cost of gases for oxy acetylene welding.We weld using L-Ag45Sn or AG104 rods. I know the price per kg of the rods and the weight for each individual rod, so that is one down. But I don't really know how to effectively calculate the cost of the gases. Could anyone please help?
Reply:Originally Posted by rafergusonIf you look up the factory data for the tips, it should give the cfm for each tip. I know that I have seen and used that kind of data in the past. Of course, it would depend on whether or not the torch manufacturer publishes that information. So start wading through the factory data sheets and see if you can find cfm or liters per minute for the various tip sizes.Richard
Reply:Unless you are using very large tips I wouldn't bother but if you must.... start with a full tank and record all your welding time until it is empty and then do the math. I know you may use different size tips in that time frame but trying to figure costs to the nickel is just going to frustrate you. Find an average and incorporate it into your overhead charges and be sure to include a healthy profit.---Meltedmetal
Reply:It is true the welder can adjust the flow rate to some extent, but only within a somewhat limited range. I am just suggesting that the published data is a good starting point.As far as measuring the flow, not sure where you could get a flow meter for acetylene. Maybe there are correction factors that you could apply, so you could use a flowmeter intended for another gas. Oxygen is pretty cheap, so unless you are cutting the acetylene is the primary gas cost.Richard Originally Posted by Pitbull_RavenThanks for the info. Will do. But correct me if I'm wrong when I say that I think the welder can adjust the flow rate by turning the valves on the torch, right? If true, then I wouldn't be able to measure the rate for each gas without some sensor or whatnot?
Reply:Originally Posted by rafergusonIt is true the welder can adjust the flow rate to some extent, but only within a somewhat limited range. I am just suggesting that the published data is a good starting point.As far as measuring the flow, not sure where you could get a flow meter for acetylene. Maybe there are correction factors that you could apply, so you could use a flowmeter intended for another gas. Oxygen is pretty cheap, so unless you are cutting the acetylene is the primary gas cost.Richard
Reply:The amount of oxygen in the tank is proportional to the pressure (as long as the temperature remains the same). If you start a job with a full tank and finish it with, say, 85% of the initial full tank pressure, you have used 15% of the gas.Acetylene can not be calculated the same way since it is not simply compressed gas in the tank. There is another solution as long as you are welding - since most welding uses a neutral flame and a neutral flame needs a accurate mix of gases you can calculate how much acetylene you have used based on how much oxygen was used. Unfortunately I do not have the numbers for the calculations right here now, I'll try to find them later.(For cutting you can not use this method, since it uses a vast excess of oxygen.)This may not help calculations very much before a job, but if you keep doing the numbers after each job is done you'll get a handle on how much gas diffrent jobs use.
Reply:Originally Posted by G-sonThe amount of oxygen in the tank is proportional to the pressure (as long as the temperature remains the same). If you start a job with a full tank and finish it with, say, 85% of the initial full tank pressure, you have used 15% of the gas.Acetylene can not be calculated the same way since it is not simply compressed gas in the tank. There is another solution as long as you are welding - since most welding uses a neutral flame and a neutral flame needs a accurate mix of gases you can calculate how much acetylene you have used based on how much oxygen was used. Unfortunately I do not have the numbers for the calculations right here now, I'll try to find them later.(For cutting you can not use this method, since it uses a vast excess of oxygen.)This may not help calculations very much before a job, but if you keep doing the numbers after each job is done you'll get a handle on how much gas different jobs use.
Reply:Originally Posted by rafergusonGson is right on the money here. Kind of a clever approach. ...My chemistry and thermodynamics are rusty, so I might be confused.Richard
Reply:I believe your flow gauges read on cfm or something of the likes. whatever you set it at is what your using per time period then the bottle is xxx amount of cubic feet. |
|
发表于 2021-8-31 23:06:56