How Fire Extinguishers Work

Q: When is a water extinguisher dangerous?
A: A water extinguisher can put out things like burning wood, paper or cardboard, but it doesn't work well on electrical fires or fires involving inflammable liquids. In an electrical fire, the water may conduct the current, which can electrocute you.

A fire extinguisher is an absolute necessity in any home or office. While there's a good chance that the extinguisher will sit on the wall for years, collecting dust, it could end up saving your property and even your life.

In this article, we'll see exactly what fire extinguishers do and how they do it. We'll also find out what causes fire in the first place, learn the correct way to use an extinguisher and see what sort of fire suppressant works best on different types of fires.

What is Fire?
Extinguishing a Fire
We don't usually think much about how a fire extinguisher works -- until we need to use one.
Fire is the result of a chemical combustion reaction, typically a reaction between oxygen in the atmosphere and some sort of fuel (wood or gasoline, for example). Of course, wood and gasoline don't spontaneously catch on fire just because they're surrounded by oxygen. For the combustion reaction to take place, the fuel has to be heated to its ignition temperature.­

­Here's the sequence of events in a typical wood fire:
- Something heats the wood to very high temperatures. This could be any number of things -- focused light, friction, something else that is already burning.
- When the wood reaches about 500 degrees Fahrenheit (260 degrees Celsius), the heat decomposes some of the cellulose material that makes up the wood.
- Decomposed material is released as volatile gases, typically a compound of hydrogen, carbon and oxygen.
- When the gas is hot enough, the compound molecules break apart, and the atoms recombine with the oxygen to form water, carbon dioxide and other products.
- The gases, which rise through the air, make up the flame. Carbon atoms rising in the flame emit light as they heat up. (Check out How Light Bulbs Work to find out why heated objects emit light.)
- The heat of the flame keeps the fuel at the ignition temperature, so it continues to burn as long as there is fuel and oxygen.

As you can see, there are three essential elements involved in this process:
- Extreme heat
- Oxygen (or similar gas)
- Fuel

Fire extinguishers are designed to remove at least one of these elements so that a fire will die out. There are several different ways of doing this, as we'll see in the next section.

http://home.howstuffworks.com/fire-extinguisher.htm

How to Select the Right Engine-Driven Welder for the JobUnderstanding the Basics

Lincoln equipment for wire welding includes all Ranger® and all Vantage® models. Other Lincoln equipment can be upgraded to provide this capability: Pipeliner™ 200 D, all Classic® models and SAE-400.

Engine-driven welders are generally used when electric power is not available for arc welding. Usually these are outdoor applications. However, engine-drive welders are often used for indoor applications when it is not convenient to supply power to electric "plug-in" arc welders. These indoor situations include everything from minor repair jobs to major plant shutdowns. When operating engine-driven welders indoors, vent the exhaust outside if at all possible, or use in large spaces with good ventilation.

The basic considerations when choosing an engine-driven welder are:
- Application
- Engine Type
- Portability
- AC Generator Power

For AC TIG welding the Lincoln Ranger™ 10,000 and 3 Phase have an AC weld output to which an optional TIG Module can be attached. Although the Ranger™ 305 G (shown) & D and Vantage products do not have an AC weld output, a Precision TIG® 225 or an Invertec® V205-T AC/DC inverter can be connected for AC TIG welding.

Application
In trying to select an engine drive, the first thing to consider is the application. Ask yourself these questions:
1. Is this new construction or a repair job? Also, what is the size of the project?
2. Is there a particular welding process you would like to use? You may want to stick with a process with which you feel most comfortable, or there may be a certain process required on the job.
3. Is this a pipe welding project? The equipment chosen needs to produce an arc suitable for this type of work.
4. Will the job require arc gouging? Arc gouging is repair work usually done in industrial jobs.
5. What type of material needs to be welded? Most of the time the material will be a common mild steel plate. However, if it's aluminum, the welding will require different equipment.
Using this information, match it to the welding processes described below:

Process Descriptions
Stick Welding - CC (constant current) stick welding is the most common choice for field work. Electrode (welding rod) diameters most commonly used are 3/32", 1/8" and 5/32". The simplest equipment will handle a wide variety of construction and repair applications. Output is measured in amps, and up to 200 amps is sufficient for the electrode sizes mentioned. Most equipment is DC (direct current) output for best arc stability. A 200-amp welder is usually able to get the job done.

Pipe Welding - Pipe welding is most often done with stick electrodes. Look for equipment which specifies it will pipe weld, meaning that suitable arc characteristics are specifically provided for this process. Electrode diameters are typically 5/32" and 3/16", and 200 amps is sufficient for this process.

Arc Gouging - Arc Gouging is a process for removing metal. It is most commonly done in the stick mode. An arc is used with a carbon rod to melt metal and compressed air blows the molten metal away. Gouging is used to remove bad welds and to repair cracks. Most operators use equipment with 400 to 600 amps for higher productivity with 5/16" or 3/8" diameter carbon rods. However, smaller rods can be used with lower amperage. For example, a 5/32" carbon rod can be used with 150 amps. Usually a separate compressor supplies the air. A few engine-driven welders are manufactured with built-in compressors.

Wire Welding - CV (constant voltage) wire welding requires a wire feeder. Wire welding's main benefit is greater productivity: more weld metal can be deposited than for stick during the same amount of time. Although wire welding is much less common compared to the above processes, the application is growing. The engine-driven welder must have a CV-wire capability. Since most engine-driven welder work is outdoors, self-shielded flux-cored wire (which requires no shielding gas) is highly recommended to keep the process simple. When welding under windy conditions, the shielding gas associated with gas-shielded processes (solid wire or gas-shielded flux-cored wire) may be blown away, resulting in poor quality welds. Output is measured in Volts and Amps. Wire diameters are typically .035" and .045", although 5/64" is often used for higher productivity. A welder with 30 volts and 300 amps is usually sufficient for many applications up to 5/64" wire.

TIG Welding - a slower, but more precise type of welding well-suited for thin materials and unusual alloys. A TIG torch and shielding gas are required. If welding on aluminum, an AC weld output is required from the engine-driven welder and a high-frequency generator is attached to start and sustain the arc. Or, an AC TIG welder can often be powered from the engine-driven welder's AC generator, if at least 8,000 watts is available. Most TIG welding is done below 100 amps.

Plasma Cutting - a metal cutting process which utilizes an arc and compressed air. The engine-driven welder's AC generator can often supply power to a plasma cutter. At least 8,000 watts of power is recommended.
The Lincoln Vantage 500 and SAE 400 will gouge up to 3/8" carbons with a separate compressor. An Air Vantage™ 500 has a built-in compressor.

Engine Type
After the application has been defined and the welding process has been selected, the next step is to choose the engine. Diesel, gasoline or liquid propane gas (LPG) are the choices. A diesel engine offers better fuel economy than a gasoline engine, and diesel fuel does not ignite as easily as gasoline. Refineries almost always require diesel-fueled machines rather than gasoline-fueled machines. Another consideration for large jobs is whether the fuel is being supplied at the job site. If so, it is usually diesel, but whatever the fuel, the cost savings will usually determine the engine choice.
Gasoline engines are sometimes preferred in cold weather climates because they start more easily without extra starting aids, such as ether start kits and winterized fuel for colder weather.
LPG is much less common, but becomes an important alternative choice when diesel and gasoline exhaust emissions are not permitted for indoor applications.
A spark arrester may also be required in forest and oil service areas.

Portability
For pipe welding Lincoln engine-driven welders include the Ranger™ 250, 305 G & D, Pipeliner® 200 D (shown), all Classic™ and Vantage machines, and SAE-400.
Sometimes the need for portability will be the main factor in equipment selection. If an engine-driven welder needs to be carried or lifted to a work area, having a small gasoline stick welder will normally be the best answer.

AC Generator Power
AC power is sometimes required on the jobsite for grinding welds or for lights when working at night. Normally, 3,000 watts of AC generator power is plenty of power for these applications. Ground Fault Circuit Interrupters (GFCIs) are recommended and may be required. An AC TIG welder or plasma cutter will require more power - typically 8,000 watts minimum.

Additional Help
Product literature published by welding equipment manufacturers provides additional information that cannot be covered here in detail. Company sales representatives and the customer service departments are also excellent sources of information for technical questions on applications and products.
Click Here for details on Lincoln Engine Driven Welder / Generators

http://www.lincolnelectric.com/knowledge/articles/content/enginedrive.asp

Tips on Handling Welding Rods

Welding rods get no respect. Out in the field I've seen guys throwing 50lb. rod cans from the truck onto the ground, torching cans open diagonally, beating the wrong end open with a chipping hammer and every other conceivable tool, and leaving open rod cans out in the open.

Let's look at what's wrong with each…

First and foremost, ALWAYS open the "right" end of the can. Some cans and boxes even say "open other end", or "don't open this end", or "the other end moron!." (last one made up by me.) The reason you need to open the right end is because you can damage the flux coating. You want to open it on the side where the rod is bare for the stinger, or electrode holder. There's a lot less chance of damaging the flux that way. 7018 is very prone to flux damage while 6010 is a lot tougher.

Most guys out in the field aren't gonna' be thinking about the welding rods inside the can as they toss them from the truck to the ground. When the cans get manhandled the flux gets jarred loose on the welding rods inside. It's bad enough when the flux gets chipped off the end of the rod, flux chipped from the middle and you can pretty much kiss that rod goodbye. It's worse, if you don't realize it's chipped because right in the middle of a good weld you'll suddenly be welding with no flux. No flux equals no shielding from the atmosphere, and that equals a garbage weld.

You can use a lot of different ways to open rod cans out in the field if you are careful. I've even used the P38 C ration can opener I had in the army.If you use an oxygen/acetylene torch you need to be real careful not to burn the flux on the rods inside.

You can open a rod can with a chipping hammer, but it's not advisable. You gotta' be sure and hit it just right, at the edge of the can. You should hit the edge with the hammer follow-through swinging away from the can, not striking down into the can at the top. (I'm sure the electrode manufacturers are cringing when they read this!)

Of course the best way is whatever the can is designed for, some of them open like a sardine can, but a lot of times it doesn't work so you gotta' improvise.

Leaving open cans out allows moisture to get into the flux. Moisture in the flux can cause porosity, or worm holes in the weld. Rods should be stored in a proper oven or unheated container if they don't need the moisture protection. 7018 needs an oven, while 6010 doesn't need the heat, but still needs to be kept protected.

http://www.rodovens.com/welding_articles/welding-rods.htm

Under Water Welding - Article

Current Concerns - from Professional Engineering Magazine

Take welding – there's a good solid engineering skill to have. Good welders are worth their weight in gold, but even harder to come by are good underwater welders. And David Keats should know as he has made a successful career of it.

Keats started out as a conventional welder, but moved into what can be described, literally, as a very different environment. As a specialist underwater welder his abilities were in high demand, in waters both inland and offshore. He spent much of the 1980s working in the North Sea, where he says divers like him were considered expensive commodities. “We were there to do a very specialised job and there was no room for any baggage. If you weren't up to scratch you weren't given a second chance,” he says.

Keats says commercial divers, particularly offshore, are treated as costly tools, shipped in to do a job and shipped out as soon as the work is done. “It sounds glamorous, but the reality of travelling all over the world to different rigs and structures is very different.”

Of course there is the perception that all offshore work is higher up the danger stakes than engineering work on land. Where offshore diving is involved, Keats says the dangers are real, but there are mechanisms and legislation in place to keep divers safe. “You are working in a hostile environment and have to act accordingly,” he says. “There are real issues to be aware of, and unfortunately when something goes wrong it tends to do so in a big way.”

Safety Splash

As managing director of South-Yorkshire based Speciality Welds. Keats is now more involved in the safety aspect of commercial diving. Although he is still a certified commercial diver, the company does not provide a diving service as such. Instead, it acts as a consultant on general and underwater welding projects, assisting with specifications, quality control and quality assurance management, as well as training divers. It also manufactures and sells welding equipment and consumables.

The first mind block for the uninitiated to get past is how welding could possibly work underwater, as electricity and water do not mix, and power must be transported to the equipment. Keats says the problem of electrical conductivity underwater is dealt with using double-insulated welding cables, and that divers wear protective clothing so they don't get shocks. As a further precaution, current is only supplied when the diver uses it.
Only direct current is used, with a polarity chosen to maximise safety. Keats says good practice is to have the diver holding the cathode, with the work to be welded as the anode to further reduce the risk of shock, and also leakage of current into the water. “As long as the safety issues are understood and acted upon, underwater welding is safe,” he says. That said, Keats has fallen foul of current leakage in the past – and when it encapsulates the diver the result can be dissolved fillings.

Unlike scuba diving, where all breathing equipment is carried by the diver, most commercial diving is performed with an umbilical link from the surface supplying oxygen and communication to the diver via their helmet. And on top of all the diving clobber, the welder still needs eye protection, which tends to be in the form of a flip-down visor.
In the past, says Keats, most people training to become commercial divers had an engineering background of some sort, which came in useful because of the similarly practical aptitude and capability aspects required of divers. However, engineering skills are no longer a prerequisite, he says.
Much of the training work Speciality Welds does is in collaboration with the Underwater Centre at Fort William in the Scottish Highlands. As the UK's national commercial diving school, the centre provides qualifications approved by the Health and Safety Executive.
Unfortunately, says the centre's chief diving instructor, Alf Leadbitter, there is no way of telling at first glance who will make a good commercial diver, but there is certainly a steady demand for qualified underwater engineers. There is plenty of scope for underwater labourers too to do general cleaning and maintenance jobs.

Leadbitter says the main call for commercial divers tends to be for inspection purposes. “This might be periodic visual inspection of underwater jackets and rigs or non-destructive testing. Obviously it's better to have an engineer who can dive rather than having to rely on data collected by non-engineering divers, as the engineer can problem solve on the spot, rather than having to go back and report any findings and wait for further instructions.”

Most divers do what he calls this “peculiar” job because of the passion they feel for it. “The best part has to be getting paid to do what you enjoy, but it must be remembered that really the diving is only the means to get to work – it's just more exotic than taking the bus. At the end of the day, you are paid for the skills you use once you've got there, not because you can dive.”
The passion for diving that Leadbitter talks about is also what attracted Phil Richards, director of Commercial and Specialised Diving Services in Bournemouth, Dorset. What keeps Richards in the industry is the wide variety of work. Although much of it is structural engineering, covering remedial and new build work on piers, locks, canals and bridges, he finds that underwater work on ships is the next most common form of employment for commercial divers. “Work off ships typically includes cleaning and replacing propellers, painting hulls and performing upgrades underwater,” he says.
“There are also instances when we've had to dive in other facilities like sewage tanks and pipelines. We're not always diving in water either, which can be an experience not to be forgotten.”

Strict Regulations

Perhaps one of the biggest bugbears across the commercial diving sector is caused by the hiring of recreational divers to do commercial work, not just because of the lost revenue, but because of concerns that safety is being neglected.

Richards says: “We often find that the simple jobs are taken on by recreational divers, all too keen to get a bit more diving in. Commercial divers can't compete on economic terms because of the safety legislation we must adhere to.”

For example, Richards says the diving at work regulations specify a minimum of four people at a diving site for safe operation: an operator, the diver, a rescue/standby diver and a diving attendant. “In a good diving team the person doing the work, the diver, should not have to be aware of anything to do with the actual diving, but should be able to get on with the work involved, almost as easily as if they were doing the job on dry land,” he says.
Remotely operated vehicles, or ROVs, have taken over some of the more hazardous roles, but there are some situations in which they are next to useless, says Richards. “However good you are at working with ROVs, they are no good for inspection work in zero visibility conditions. In those cases a working diver has to carry out the inspection by touch.”

A Visible Difference

David Keats of Speciality Welds says the main difference between welding in air and underwater are safety related. “Most of the time we use manual metal arc welding, which is widely used in general engineering, but underwater the environment provides completely different conditions. The skills you need are slightly different and how you weld also changes as the way a weld progresses is different.”

The main issues underwater are visibility and skill. The latter is what makes a good welder whether above or beneath water, but Keats believes the underwater environment can only compound a lack of skill. “As for visibility, if you can't see what you're doing, how can anyone possibly expect to produce a high-quality weld? It can only be guesswork.”

To address this, Speciality Welds has developed equipment that takes the guesswork out of producing high-quality welds in low- and zero-visibility conditions. For a start, the Hammerhead wet-spot welding system needs none of the traditional cleaning before welding, and can even work through painted structures. It can be used by divers and robots alike because of its automated control system which sets times for the first current level to pierce the top and base material and the second current level that joins the material together.

Keats says the objective was to create a magic box that removes the problem of poor visibility, and with it even divers with little training can produce good quality welds.

http://www.specialwelds.com/underwater-welding/underwater-welding-article1.htm

Under Water Welding

Taking the Plunge: A Guide to Starting an Underwater Welding Career
Over the years, a number of people have expressed an interest in careers in underwater welding, but were unsure how to get started. Welders, students, divers, and other interested men and women have contacted the American Welding Society (AWS) for guidance. In order to help those prospective underwater welder-divers, the D3B Subcommittee on Underwater Welding has provided answers for eight commonly asked questions.

This article was prepared by the American Welding Society's D3B Subcommittee on Underwater Welding.

The answer to the questions presented in the article are not intended as recommended practice nor as endorsement of any definitive means of pursuing underwater welding as an occupation. Rather, the aim is to provide enough useful information to assist those interested, as well as define some of the mis-conceptions associated with the trade. For additional information and/or a need for specialized training, the subcommittee recommends ANSI/AWS D3.6, Specification for Underwater Welding, as a comprehensive reference and resource for industry-accepted practice.

1. What skills are prerequisite to entering the field of underwater welding?
The skills suggested for entering the field of underwater welding can best be defined by the following typical description of a welder-diver from the AWS D3.6 Standard and the qualifications generally recognized.

"Welder-diver: A certified welder who is also a commercial diver, capable of performing tasks associated with commercial subsea work, weld setup and preparation, and who has the ability to weld in accordance with the AWS D3.6, Specification for Underwater Welding Specification for Underwater Welding (i.e., wet or dry), and other weld-related activities (see item 7.0)."

By description, an experienced welder-diver must possess: commercial diving skills (i.e., be familiar with the use of specialized commercial diving equipment, have an understanding of diving physiology, diving safety, rigging, the underwater environment, communication, etc.); weld setup and preparation skills (i.e., the ability to perform tasks typically assigned to a fitter or rigger, such as materials alignment and materials preparation including beveling, stripping of concrete, fitting a steel patch or repair plate, etc.,); and the ability to certify to a required underwater weld procedure.

2. I am a certified surface welder, what other training do I need to qualify as a welder-diver?
The majority of work performed by an average welder-diver does not involve the welding operation itself, but rather executing the tasks that lead up to and follow the actual welding activities. Except under special circumstances, a welder-diver in most cases must posses both certified welder skills and commercial diving skills.

It is suggested that if you have no prior commercial diving experience you should attend one of the recognized commercial diving schools. Commercial dive schools vary insofar as duration of course, cost, etc., however, most offer a basic commercial diver certificate upon successful completion. The candidate may be required to pass a diving physical prior to school acceptance and in some cases a written exam. It is suggested that a dive physical be taken regardless, to avoid going through the expense of training only to later find you have a disability that prevents your entering the profession. A listing of U.S. commercial diving schools accredited by the Association of Commercial Diving Educators can be obtained by contacting: Association of Diving Contractors International (ADC), 1960 FM 1960 W., Suite 202, Houston, TX 77069; (281) 893-8388; FAX (281) 893-5118.

As a general rule, candidates seeking underwater welding as a career will decide whether or not they are comfortable with their career choice after completing basic commercial dive training.
Once that basic commercial diver training is completed, it is common practice to apply for employment at one of many commercial diving companies that offer underwater welding as a service. An interview with the company of your choice is recommended to express your career goals in underwater welding and past welding experience. Expect to begin your career as a diver tender (apprentice diver) initially. As a diver tender you will gain valuable practical experience while learning the trade.

Before performing on-the-job underwater welding, most diving contractors will require that you achieve sufficient skill in wet and/or dry underwater welding to pass qualification tests and be certified in accordance with the requirements of ANSI/AWS D3.6, Specification for Underwater Welding. The time required to advance to welder-diver varies subject to supply and demand of welder-diver personnel, skill, motivation, experience and other factors. Most commercial diving firms have their own policies and procedures regarding this matter.

3. I am already a certified diver, what other training do I need to qualify as a welder-diver?
The welding processes, classes of weld and qualification tests associated with underwater welding are described in ANSI/AWS D3.6. We recommend the specification as a reference for weld procedure and welder qualification. It is also a good source of other helpful information.
If you are already certified as a "commercial diver" and work for a company that offers underwater welding services, it is recommended that you communicate to your company your career objectives and ask what welder skills they are looking for. If you are unemployed or do not work for a company that offers underwater welding services, it is suggested that you communicate with the commercial diving firm of your choice that offers underwater welding services and train to its requirements.

If you are certified as a "scuba diver" (e.g., NAUI, PADI, etc.), it is suggested that you attend a commercial diving school. Sport dive training does not include the safe use of commercial diving equipment, offshore commercial work environment/safety, and other education as recommended by the Association of Diving Contractors Consensus Standards for Commercial Diving Operations.

Underwater welding is a skill you also have to master once you obtain the basic commercial diving skills required. Again, it is suggested that you communicate with the commercial diving firm of your choice that offers underwater welding services, and train to its requirements. Each commercial diving firm has its own policies and procedures regarding this matter.

4. What are the age limitations of a welder-diver?
There is no age restriction on commercial welder-divers. There are, however, physical requirements. It is recommended and generally required that all commercial divers pass an annual dive physical. ADC has an industry-accepted dive physical format that is used by many of its members in the United States and other countries (e.g., some companies may have other requirements, subject to the regulations of the country where they are located, etc.).
The commercial diving profession is physical demanding. It is rare to see an active commercial welder-diver over the age of 50.

5. What is the availability of work for an entry-level welder-diver?
This is a difficult question to answer. It is more appropriate to ask the company with whom you seek and/or gain employment. There are a number of diving procedures that serve the various types of underwater industrial requirements, each of which have different underwater welding needs. Like many professions, work availability is always subject to: supply vs. demand, the economics of a given industry, whether you are free to relocate outside your place of residence (including overseas), what other related skills you have in addition to diving and welding, etc. A number of welder-divers have established a reputation of high-quality workmanship and/or productivity and are asked for by name. The company you choose to work for is also a factor.
The answer to the question is that there is work available for entry-level welder-divers; however, the amount of work available is subject to the aforementioned variables.

6. What salary can I expect to make as a welder-diver?
An average salary vs. grade index would be interesting to look at if there were one, but the truth of the matter is that salaries for welder-divers cover a wide range. We know some welder-divers earn $15,000 per year while others earn in excess of $100,000. Because the majority of welder-divers are paid on a project-by-project basis, salaries are subject to the same variables as work availability. In addition, other factors such as depth, dive method and diving environment affect pay rates. The company with whom you gain employment should be able to tell you the salary range you can expect to earn.

7. What other skills are recommended to supplement my qualifications as a welder-diver?
The commercial diving and underwater welding industry is as diverse as the customers it serves. The welder-diver qualifications required for a given assignment vary from project to project. Ideally, a diving contractor would like its welder-divers to be "a jack of all trades and a master of them all!" Practically speaking, possessing the skills that are common to underwater welding operations, in addition to welding and diving, are recommended. Primarily these skills are: underwater cutting (oxyfuel, abrasive water jet, mechanical cutting equipment, etc.); fitting and rigging; inspection and nondestructive testing (visual, magnetic particle, ultrasonics, radiography, eddy current, etc.); drafting; and underwater photography (still photo and video).
Not all welder-divers posses the variety of skills that may be required to complete an underwater welding project. Diving contractors typically combine personnel resources to satisfy the capabilities required. Hence, the more skills the welder-diver maintains the more valuable he becomes in meeting project qualification requirements. The most desirable underwater welder-divers are those who are qualified to: assist the diving contractor in pre-job planning (e.g., having the ability to photograph/video, draft and report on work requirements prior to the actual underwater welding operation); cut, clean, rig, install, and fit up the sections they will weld; and work with personnel responsible for inspecting the completed welds.

Formal training is recommended for whatever skills you wish to qualify for. Many diving contractors, and the customers they serve, work under quality programs that demand evidence of training and/or qualifications. Therefore, it is recommended that the training you receive be accredited or offer a certificate of completion (e.g., a welding certificate, a diving certificate, an ASNT Level II or CSWIP ultrasonic certificate, riggers certificate, etc.). Maintaining the qualifications you obtain is just as important as receiving them as there has been many a job lost to a welder-diver who has let his certification lapse.

8. What future career opportunities are there for an experienced welder-diver?
There are a number of career opportunities for experienced welder-divers. Many go on to become engineers, instructors, and diving operations supervisors, fill management positions, qualify as AWS Certified Welding Inspectors (CWI), and serve as consultants for underwater welding operations and other related fields.

Ideally, a career as a welder-diver should serve as a stepping stone to other opportunities for those who choose the profession.

Industry has and will continue to demand higher quality standards for underwater welds and more certification of underwater welding systems and personnel. These demands will challenge the underwater welding community to meet more complex technical specifications, safety standards, welding criteria, inspection methods, environmental factors, and other considerations. To meet these challenges, tomorrow's welder-divers will rely on the knowledge and experience of their predecessors who have gone on to become welding engineers, welding engineer divers, supervisors and instructors. These individuals will provide the technical support needed for coming underwater welding operations.

A career as a welder-diver can be an exciting and rewarding profession. It cannot be overstated that safety through training is paramount to any welder-diver candidate.
The majority of work performed by an average welder-diver does not involve the welding operation itself, but rather executing the task that lead up to and follow the actual welding activities. Except under special circumstances, a welder-diver in most cases must possess both certified welder skills and commercial diving skills.

It is suggested that if you have no prior commercial diving experience you should attend one of the many recognized commercial diving schools. Commercial dive schools vary insofar as duration of course, cost, etc., however, most offer a basic commercial diver certificate upon successful completion. The candidate may be required to pass a diving physical prior to school acceptance and in some cases a written exam. It is suggested that a dive physical be taken regardless, to avoid going through the expense of training only to later find you have a disability that prevents your entering the profession. A listing of U.S. commercial diving schools accredited by the Association of Commercial Diving Educators can be obtained by contacting: Association of Diving Contractors (ADC), 2611 FM 1960 W., Suite F204, Houston, TX 77068; (713) 893-8388; Fax (713) 893-5118.

© 2001 American Welding Society550 LeJeune Rd., Miami, Florida, USA 33126Tel. 305-443-9353 · Fax 305-443-7559http://www.aws.org/e-mail: info@aws.org