Safety

Magnum Manufacturing Incorporated 1-800-957-4344

High performance cutting, welding and safety products

Tactical and Emergency Response Cutting Systems

Underwater Cutting and Welding Systems

Repair, Maintenance and Salvage Cutting Systems

Composite oxygen cylinders

Ignition systems for cutting equipment

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MSHA approval for mines

Rated top 20% performer Dun and Bradstreet for customer service

If you are inexperienced or unfamiliar with underwater cutting, the CD is an excellent resource for a general introduction to underwater cutting and welding. Although Magnum was not around when the manual was made, Magnum has subsequently distinguished itself in the field in having more commercial divers now trained on Magnum products than any other brand.

Underwater cutting (also called burning) produces hydrogen gas that can cause explosions. Always vent any object that can trap or confine gas bubbles. Ship hulls, cargo holds, double patches and double bottoms can contain explosive gases. Vent all areas prior to cutting. Always cut from the top down to allow natural venting of flammable, explosive gases. Hydro carbons can cause an explosion so be sure to inspect all sides of an area to ensure they are not present. Pipes and pipelines must be flooded with water prior to cutting. The U.S. Navy publishes a cutting manual that can be found online.

Never cut when a pressure difference exists. Your fingers, hands or flame particles can be sucked into a hole or opening. Objects can also be blown from openings. Always drill a hole in the top and allow pressures to equalize. This is critical on gantry legs or other objects and materials that can trap gases. Venting allows gases to escape. Since gases can become trapped in mud, remove mud from around the area to be cut. When encountering packed mud, ensure the tip of the cutting tube is pointed up while effecting the cut starting at the top and pulling it to the bottom to ensure gases are not driven into the mud ahead of the cut. The same process is used for concrete filled pipes.

Do not cut in a straight line around the circumference of a pipe. Cut one half of the pile. Go back to the starting point and cut the other half of the pile using the same technique. Start at the highest point and drag the cutting tube away from the kerf to prevent bubbles from being forced into voids. This process allows bubbles to naturally escape. Sufficient safety equipment is essential. For cutting, requirements include an insulated cutting torch, oxygen hose, 2 stage regulator, heavy duty ground lead with clamp, knife switch, and if not using a battery, a DC welder for ignition.

The knife switch is located on the tender platform so power can be turned on and off through commands given by the diver. On a single throw knife switch, the negative side of the DC welder is connected to the knife switch and cutting torch (straight polarity). The positive side of the DC welding machine is connected to the ground lead. An exception is the dual pole knife switch where both the negative and positive cable run through the knife switch. When open, all current stops. Because the dual pole stops all current when open, it is the safest switch to utilize.

Ensure all connections are tight and without gaps which could cause problems with arcing or current performance. Ensure the hoses are tight and located away from the burn zone. All equipment is to be free of oil, grease or any flammable material. Oxygen is adjusted per ocean depth (to be discussed later). Check for leaks prior to cutting. Although polarity is not important for ignition, it is essential for welding. An easy way to assess polarity is to submerge an unlit burning rod and the ground clamp into a plastic bucket filled with water keeping a 2" distance between the two. Close the knife switch (make hot). Reverse polarity will cause a stream of hydrogen bubbles to emanate from the tip of the burning rod.

Prior to cutting ensure the material to be cut is properly grounded. Clean the surface of the material to ensure the clamp is properly grounded. Ensure the clamp is close to the cut area yet in a strategic position to ensure the diver never comes between the ground clamp and the cutting torch. To initiate cutting the diver signals to have the knife switch closed (make it hot). The cutting tube is ignited by bringing it into contact with the grounded material to be cut. Always purge the torch head with a blast of oxygen to remove any residual hydrogen bubbles that can accumulate from the prior cut. The diver then signals to have the knife switch open (make it cold), so cutting can be effected without continuous current. The beauty of exothermic cutting is that is can be accomplished without current on once ignited.

Polarity effects the amount of heat going into the material. Straight polarity means most of the heat resides in the work piece. Underwater cutting is accomplished using straight polarity. Cutting without power is slower but safer. Cutting with continuous power is faster but not as safe as the diver must manage a continuous arc. For this reason, continuous current cutting is best left to seasoned professionals with extensive training and experience. Never leave a knife switch hot since hydrogen bubbles can explode. Leaving a knife switch on can also discharge the battery when a battery is used for ignition. In general, the cleaner the surface the faster the cut.

The purity of oxygen for all underwater cutting should be 99.5 percent or greater. Oxygen purity is related to performance. A one percent degrease in oxygen purity will result in a 25% reduction in cutting efficiency and an increase in slag inclusion. Commercially available oxygen should be 99.9 percent pure.

Amperage settings vary. Consider the following as a starting point when oxy-arc cutting:

Cutting 3/8" 200amps.

Cutting 3/4" 225 amps.

Cutting 1 1/4" 250 amps.

Cutting 2" and above 300 amps.

A 3/8" inner diameter hose is recommended.

Steel reinforced for deep dives.

Cable considerations:

Use the same size cable for all connections. Expect at lease a 2 amps drop per 50 foot of cable. Holes or defects in cable insulation generally show up as red because of the oxides. It is a good practice to test leads on land prior to underwater use. Running your hand along the cable will test for increased resistance demonstrated by a change in heat. Hot spots must be repaired with a splice or by changing the cable. Low or no voltage and high amperage as indicated by a meter indicates a cable that requires repairing or replacing.

A two stage regulator is required capable of producing 70 cfm flow. Oxygen cutting pressure is set at 90 psi over bottom pressure.

Hose length and regulator settings

Hose length 50 feet depth (FSW)	Regulator pressure settings (psi)
10	100
20	104
30	109
40	113
50	118
60	122
70	127
80	131
90	136
100	140

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A Blackhawk™ cutting torch generates double the temperature of any acetylene torch regardless of brand because of its unique ability to ionize metal particles using oxygen. Sublimation is the key and our burning process converts metal to a liquid state in seconds. The new consumables burn like no other burning bars, oxygen lances or Slice™ rods. Our law enforcement cutting torch, also known as the tactical thermal breaching torch, is used for breaching in a variety of settings. Our precision land and underwater cutting torches operate on either compressed bottled oxygen or liquid oxygen. Simply put, if medical oxygen is safe enough to breathe, it is safe enough to cut steel. The torch enjoys unrivaled diversity ranging from aircraft maintenance to scrap wrecking yards where a diversity of alloys are encountered ranging from aluminum and stainless steel to cast iron and manganese. The Blackhawk™ torch not only cuts at a ten-thousand degree temperature in flame mode without a welder assist, the same torch can also arc cut using a welder making it quite useful for auto salvage, boat salvage and boat repair. The military cutting torch is unequaled as both a land and a marine cutting torch. Tests show the emergency cutting torch is superior to oxyacetylene cutting equipment through its use of interchangeable collets to accommodate different cutting rod diameters. Although we have described our proprietary process as magmafusion™ welding distributors might have our torch listed under dated terms like exothermic, endothermic, Ultrathermic®, Aquathermic®, sea torch, sea cutting torch, oxy-arc cutting torch, thermal dynamics cutting torch, thermadyne™ air carbon arc gouging torch, oxygen cutting lances, thermolance oxygen lance, superblast cutting rods, aqua lance, surweld, and proweld, but it will not be listed as an oxy-gasoline cutting torch because it uses only oxygen like that sold by air liquide or other popular welding suppliers. Consider a forced entry tactical torch or submersible cutting torch as an indispensible asset to your cutting arsenal, sometimes referred to as an oxygen lance flame cutting torch to round off a rather long list of nomenclature. What is far more important is the process lends itself as the ideal entry torch when it comes to immediate cutting, gouging or piercing any material in seconds particularly as a convenient preparation for arc welding without time consuming grinding. Those building contractors using burning bars, burning rods, burning bars, thermic lances or oxygen lances will find our Blackhawk™ torch far easier to operate and control because of its unique design and lower oxygen regulator. Magnum was the first company that offered an oxygen regulator at the base of the torch to control flame length and is superior in control over gouging rods, making the ultimate maintenance torch. All of our high performance torches use standard brass collets to hold cutting rods and cutting tubes. Rods or tubes made by Caldo®, Oxylance®, Broco® and Arcair® will work in our cutting torch with greater performance according to our factory comparison tests. The Navy Seals recently preferred our cutting torch and cutting tubes to all ot her brands on the market. Commercial construction and heavy equipment is a prime market for our cutting torch when it comes to land projects. Nevertheless, when it comes to the serious challenges of underwater construction, commercial divers and diving organizations will find our torch an indispensible asset. Our customers include heavy construction equipment rental agencies, equipment contractors and contractors in general who have found our cutting torches and cuttring consumables superior to other cutting and welding consumables currently on the market. Simply put, there is no faster or more powerful cutting tool or cutting torch on the market for either land or underwater assignments. Even novices find out Blackhawk™ cutting torch easy to use.