Tips and FAQs.
Our carbon dioxide- filling facility shuts down at 4:30 pm for the day. This is part of our daily lock-up procedure. There are six filling systems that need to be shut down before 5:00 pm closing.
To fill your cylinder between 7:30 am and 4:30 pm, while you wait, involves bleeding the carbon dioxide fill-lines and pump down to a temperature that will allow the pump to “prime”. You are paying $10.00 extra for the lost time and lost product used to cool the filling system to priming temperature.
We get this question a lot! The best source for regulator pressure- setting is your owner’s manual! The manufacturers have done all the experimentation for you. They have recommended regulator output- pressure settings for every tip style and size they make and every metal thickness you are cutting, brazing, or welding. If you have no manufacturer setting- information available:
RULE OF THUMB (SINGLE-HOLE WELDING AND BRAZING TIPS)
Single-hole tips are usually stamped with a one or a two-digit number. Set both your fuel-gas regulator and oxygen regulator pressure to this stamped number- value.
For example: A tip stamped “4” will require 4 psig fuel gas pressure, and 4 psig oxygen pressure.
CUTTING TIP RULES OF THUMB DO NOT APPLY TO INJECTOR-STYLE CUTTING TORCHES!
RULE OF THUMB (MULTI-HOLE CUTTING TIPS, OXY / ACETYLENE)
Recommended oxy/acetylene cutting tip pressures vary with size. If you have no manufacturer setting- information, and are cutting less than 1 ½” thick steel, set the acetylene regulator for 10 psig, and the oxygen regulator for 40 psig.
RULE OF THUMB (MULTI-HOLE CUTTING TIPS, OXY / FUEL GAS)
Recommended oxy/ fuel gas (propane, propylene, natural gas) cutting tip pressures also vary widely with size. If you have no manufacturer setting- information, and are cutting less than 1 ½” steel, set the fuel gas regulator for 10 psig, and the oxygen regulator for 45 psig.
RULE OF THUMB FOR MULTI-FLAME HEATING TIPS (“ROSEBUDS”)
There is no rule of thumb for multi-flame heating tips! If you have setting and use questions concerning “rosebud” tips, call us! We may be able to help you avoid serious flashback and /or melt-down issues resulting in fires!
NO! A great many require a shielding gas for proper application. The manufacturer’s recommended shielding gas is critical for their successful use. Call us with your wire manufacturer’s name, and wire type and size for this information.
Preheating is dependent on two primary things: Alloy type and thickness.
For most carbon steels-
RULE OF THUMB: Preheat 10º F for every “point” (.01%) of carbon content in the base metal.
Both acetylene and liquid fuel gas cylinders must to vaporize enough gaseous product in the cylinder head-space to feed your torch tip properly. Cold weather (usually around +15º F and below) slows the ability of the fuel gas cylinder to vaporize enough gaseous product to accomplish this. As the available vaporized gas in the cylinder head-space is consumed, the cylinder appears to “empty” itself.
When the cylinder is brought back inside and warmed, proper vaporization again takes place and the cylinder appears to “refill” itself.
Carbon dioxide is filled into the cylinder in its liquid phase, and is held in the liquid phase by the pressure of the evaporated liquid in the cylinder head-space. The gas you withdraw from the cylinder lowers the gaseous head-space pressure, allowing further evaporation of the liquid carbon dioxide. Your regulator contents gauge will read pretty close to full cylinder pressure until almost all of the liquid carbon dioxide has evaporated. Then, as you have experienced, it drops off like a rock!
This phenomenon is known as regulator freeze-up. There is a tremendous drop in the gas temperature as the gaseous carbon dioxide is withdrawn from the cylinder. The temperature can drop low enough for the gaseous carbon dioxide to desublimate, or immediately change from a gas to a solid. When these solid crystals form (dry ice), they clog up the seat assembly of your regulator. If enough of these crystals form, they can completely shut off the regulator output.
The higher the flow rate, the colder the gas becomes. High flow rates are a common cause of regulator freeze-up.
Another common cause of regulator shut-down is using carbon dioxide cylinder which is too small to support the desired withdrawal flowrate. The small gaseous head space cannot be reproduced fast enough by evaporation of the liquid carbon dioxide.
For example, a 5 lb.-size carbon dioxide cylinder will not support a 40 cfm gas flow in a continuous MIG welding operation.