You are probably experiencing the effects of Duty Cycle. Many machines are designed to shut down automatically after a period of continuous operation. This feature is there to protect the machine from over-heating. Click here for a more detailed explanation of duty cycle.

It depends on a couple of things; the size of the balloons and the tank size. Temperature and tank pressures are also factors. The chart below will give you an approximate number of balloons based on these factors. The chart assumes that the tank is full and that you're not over-inflating the balloons. [You won't get 125 balloons if the tank is half full and the 9'' balloons you've bought are inflated to twice that size.]

Helium Cyl Size	Tank Pressure	9''	11''	14''	16''
40 cu.ft.	2200 psi	125	60	35	25
60 cu.ft.	2200 psi	175	100	50	40
80 cu.ft.	2200 psi	250	120	70	50
110 cu.ft.	2200 psi	340	180	90	75
220 cu.ft.	2200 psi	680	360	180	150
300 cu.ft.	2650 psi	940	500	250	200

Arc welding electrodes are coded by the American Welding Society [AWS]. Each AWS number gives complete information about the electrode.

Classifications of mild and low alloy steel electrodes are based on an 'E' prefix and a four or five digit number. The first two digits [or three, in a five digit number] indicate the minimum required tensile strength in thousands of pounds per square inch [psi]. The next to last digit indicates the welding position in which the electrode is capable of making satisfactory welds. [1 = All positions, 2 = Flat position and horizontal fillets]. The last digit indicates the type of current to be used and the type of covering on the electrode [see fig. 1].

fig. 1

Example: E6010

POWER CABLE

WELD CABLE

TIG [Tungsten Inert Gas] and MIG [Metal Inert Gas] refer to two electric welding processes in common use today. They are very different and each has characteristics making them suitable for particular welding applications. In brief;

TIG welding uses a non-consumable electrode that provides the arc and a separate filler material in the form of a rod. In addition, the TIG torch delivers a shielding gas to the weld site to minimize weld oxidation and/or alter the characteristics of the weld metal. In technique it is much like handling a oxy-acetylene torch though it is an electric process rather than flammable gas. It produces high quality welds and is especially suitable for aluminum and stainless steel metals.

MIG welding uses a device to automatically feed welding filler material into the weld site. The material is in the form of wire and the wire itself is the electrode. As it is with the TIG torch, the MIG torch delivers shielding gas to the weld site although welding wire is available that produces its own shielding gas in much the same way flux coated stick electrodes do.

The American Welding Society refers to these two processes as GTAW [gas tungsten arc welding] for TIG and GMAW [gas metal arc welding] for MIG.

The type of torch you are using and the thickness of material being cut determine the proper size cutting-tip for use in oxy-acetylene flame cutting.

Reproduced below are the cutting tip charts for two of the most popular types of torches in use. Call your local Haun Welding Supply branch if you don't see yourparticular torch listed here.

Harris Cutting Torches & Tips

Thickness of Metal in Inches	Tip Size	Oxygen Pressure [PSIG]
Light gauge to 3/16 3/16 - 3/8 3/8 - 5/8 5/8 - 1 1 - 2 2 - 3 3 - 6	000 00 0 1 2 3 4	15 - 30 20 - 30 30 - 40 35 - 50 40 - 55 45 - 60 50 - 75
For acetylene, use one piece tips with 5-6 PSIG acetylene pressure. For MAPP, natural gas, or propane, use two piece tips with 4 oz/sq.in. or higher fuel gas pressure

Victor Cutting Torches - Tip Series 1-101, 3-101, 5-101

Metal Thickness	Tip Size	Cutting Oxygen[PSIG]	Preheat Oxygen[PSIG]	Acetylene [PSIG]
1/8' 1/4' 3/8' 1/2' 3/4' 1' 2' 3' 4'	000 00 0 0 1 2 3 4 5	20/25 20/25 25/30 30/35 35/35 35/40 40/45 40/50 45/55	3/5 3/5 3/5 3/6 4/7 4/8 5/10 5/10 6/12	3/5 3/5 3/5 3/5 3/5 3/6 4/8 5/11 6/16
-CAUTION - At no timeshould the withdrawal rate of an individual acetylene cylinder exceed one-seventh of the cylinder contents. If additional flow capacity is required, use an acetylene manifold of sufficient size to supply the necessary volume.

Tip sizes and gas regulator settings are dependent on the thickness of the material to be welded and the type torch being used

Reproduced below are the tip charts for two of the most popular types of torches in use. Call your local Haun Welding Supply branch if you don't see your particular torch listed here.

HARRIS Welding Torches & Tips

Metal Thickness	Tip Size	Rod Size	Oxygen [PSIG] E. P. U. P.		Acetylene [PSIG] E. P. U. P.
3/64' 1/16' 3/32' 1/8' 3/16' 1/4 - 3/4'	1 3 5 5 7 9	1/16' 1/16' 3/32' 1/8' 5/32' 3/16 - 3/4'	1 3 5 5 7 9	15 20 25 25 30 35	1 3 5 5 7 9	.25 [4 oz.] or more
E. P. = Equal Pressure U. P. = Universal Pressure

VICTOR Welding Torches & Tips

Metal Thickness	Tip Size	Oxygen [PSIG] Min. Max.		Acetylene [PSIG] Min. Max.
Up to 1/32' 1/16 - 3/64' 1/32 - 5/64' 3/32 - 7/64' 1/16 - 1/8' 1/8 - 3/16' 3/16 - 1/4' 1/4 - 1/2' 1/2 - 3/4 3/4 - 1'	000 00 0 1 2 3 4 5 6 7	3 3 3 3 3 4 5 6 7 8	5 5 5 5 5 7 10 12 14 16	3 3 3 3 3 3 4 5 6 8	5 5 5 5 5 6 7 8 9 10

Brazing is a process wherein metal is joined together by heating the base metal to approximately 800°F and then using a non-ferrous filler metal having a melting point below that of the base metal. The filler metal melts and adheres to the base metal. The base metal does not melt and there is no fusion as in welding processes.

Most commercial metals can be brazed. Although brazed joints have a relatively high tensile strength they do not possess the full strength properties of conventional welding techniques. One very useful characteristic of brazing is its ability to join dissimilar metals.

Duty cycle is the amount of time in a ten-minute period that a welding machine may be operated continuously without fear of overheating or damaging its components. Duty cycle is expressed as a percentage [%]. For example, a machine with a 60% duty cycle at 200 amps may be operated continuously for 6 minutes at that amperage [60% of 10 minutes]. The remaining four minutes of the cycle should be used to cool the machine down. Duty cycle percentages will change for a given machine depending on the output selected. It is possible to have several duty cycles listed. In general, the higher the output the, lower the percentage or time allowed.

You should also note that many welders manufactured today are equipped with devices that will automatically shut the machine down if operating temperatures are exceeded. Letting the machine cool down will normally reset the system.

The primary purpose of shielding gas is to displace the air in the weld zone to prevent contamination of the weld zone by oxygen, nitrogen, or water vapor. Shielding gas for TIG welding can be argon, he­lium, or a mixture of argon and helium. Argon is the most popular. Argon has greater cleaning action and provides a more stable arc than Helium. Argon is heavier than air and provides a blanket over the weld that protects it from contaminants. Helium is lighter than air, requires a higher gas flow than argon and is more expensive to use. Helium allows greater penetration and faster welding speeds because the arc is hotter in the helium atmosphere than in the argon atmosphere. For MIG welding a mixture of argon and helium is sometimes used in welding metals that require greater heat. Argon is used for most TIG welding applications.

Argon [A], helium [He], and carbon dioxide [CO2] are the principal shielding gases used. Oxygen [O2] is used as an additive to stabilize the welding arc. Listed below are some of the more common gas and gas mixture applications.

Recommend MIG wire for:
Optimum weld performance on clean, oil- and rust-free material.
Best arc performance and feedability.
Good weld puddle control, good wetting action and a wider operating range.

Recommend Metal-Cored wire for:
Less prep-time - Performs better on rust or mill scale.
Good wash-in and tie-in and good bead wetting.
Higher deposition rate at the same welding current as MIG.

The choice of DC+ [DCRP]or DC- [DCSP] depends on the weld characteristics required. Straight polarity [DCSP] means the electrons flow from the electrode to the work, concentrating most of the heat on the weld. Reverse polarity [DCRP] means the flow of electrons is from the plate to the electrode causing greater heat at the electrode and the electrode tends to melt off. DCSP produces a narrow, deep weld resulting in a more rapid weld and less distortion of the base metal. DCRP forms a wide and shallow weld.