4AE3 U6 C2 Review

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What is a potential consequence of poor welding technique?

Enhanced flexibility of the structure
Introduction of gas pockets or solid impurities into the weld metal (correct)
Improved durability of the weld
Increased strength of the parent metal

What can occur when the heat from welding and flame cutting affects the weld metal?

It becomes brittle and susceptible to cracking (correct)
It becomes more resistant to corrosion
It becomes stronger and more durable
It becomes more flexible

Why is it important to design a weld joint using sound engineering practice?

To ensure the weld is aesthetically pleasing
To ensure the weld is strong enough for the service conditions (correct)
To reduce the cost of the welding process
To increase the weight of the structure

What is the purpose of the ASME Code Section IX?

To provide guidelines for welding and brazing (D) Signup and view all the answers

What is the consequence of a defective weld joint?

It will not be strong enough for the service conditions (A) Signup and view all the answers

Why do provinces in Canada have laws stipulating that boilers, pressure vessels, and pressure piping be made in accordance with ASME Code Section IX?

To ensure the safety and integrity of these structures (B) Signup and view all the answers

What is the definition of welding according to ASME IX?

A localized coalescence of metals produced by heating or pressure with or without filler material. (D) Signup and view all the answers

What is the main difference between non-fusion and fusion welding?

Whether the parent metal is melted or not. (C) Signup and view all the answers

What is the role of flux in the non-fusion welding process?

To prevent oxidation of the metal surfaces while they are being heated. (D) Signup and view all the answers

What is the primary difference between brazing and soldering?

The temperature at which the process is performed. (D) Signup and view all the answers

Which of the following is NOT a characteristic of non-fusion welding?

The parent metal is melted. (C) Signup and view all the answers

What is the typical temperature range for soldering?

Below 450°C. (D) Signup and view all the answers

What is the primary advantage of using brazing for constructing copper heating boilers?

Copper is an excellent heat conductor. (D) Signup and view all the answers

What is the purpose of ensuring the parts fit properly before brazing or soldering?

To ensure the joint is clean and free of grease. (D) Signup and view all the answers

What is the difference between silver brazing and regular brazing?

The filler metal is stronger in silver brazing. (C) Signup and view all the answers

What is the primary purpose of heat in the non-fusion welding process?

To melt the filler metal and form an adhesive bond. (B) Signup and view all the answers

What is the approximate pressure of a fully charged oxygen cylinder?

2175 psi (B) Signup and view all the answers

What is the purpose of a pressure regulator in oxyacetylene welding and cutting?

To reduce the pressure of the gas to the required level (C) Signup and view all the answers

Why are oxygen and acetylene regulators not interchangeable?

Due to different thread types (C) Signup and view all the answers

What is the typical colour of the hose that supplies oxygen to the welding/brazing torch?

Green (A) Signup and view all the answers

What is the minimum temperature required to cut steel using oxyacetylene cutting?

870°C (D) Signup and view all the answers

What is the purpose of a flashback arrestor in oxyacetylene welding and cutting?

To prevent explosive flashbacks (D) Signup and view all the answers

What is the typical pressure of oxygen used to cut steel plate?

280 kPa (A) Signup and view all the answers

Why can't stainless steel be flame cut directly?

Because it rapidly forms heat-resistant oxides (A) Signup and view all the answers

What is the purpose of the cutting handle valve in oxyacetylene cutting?

To permit high-pressure oxygen to jet from the cutting tip (B) Signup and view all the answers

What is the approximate pressure of a fully charged acetylene cylinder?

1725 kPa (A) Signup and view all the answers

What is the primary difference between brazing and soldering?

Brazing uses a higher temperature than soldering (A) Signup and view all the answers

Which type of gas is used for brazing or very large soldered joints?

Acetylene (B) Signup and view all the answers

What is the purpose of flux in brazing and soldering?

To remove oxidation and promote the flow of filler metal (D) Signup and view all the answers

What is the primary characteristic of fusion welding?

The parent metal melts and mixes together (D) Signup and view all the answers

Which type of welding is no longer used for industrial purposes due to weak weld joints?

Forge welding (D) Signup and view all the answers

What is the term for the fuel used in OFW processes?

Any fuel that produces a high-temperature flame (A) Signup and view all the answers

What is the primary difference between OFW and brazing?

OFW heats the parent metal to above the melting temperature (C) Signup and view all the answers

What is the purpose of a hand torch in soldering?

To provide the correct amount of heat for the job (A) Signup and view all the answers

What is the term for the equipment used for brazing and soldering?

Non-fusion welding equipment (B) Signup and view all the answers

Why is MPS gas used for soldering copper pipe?

Because it produces a higher temperature than propane (B) Signup and view all the answers

What is the primary advantage of OFW over other welding processes?

Portability of equipment (C) Signup and view all the answers

What is the approximate temperature at which acetylene burns with pressurized oxygen?

3300°C (B) Signup and view all the answers

Why is acetylene dissolved in liquid acetone in the cylinder?

To reduce the risk of explosion (D) Signup and view all the answers

What is the purpose of the porous filler material in the acetylene cylinder?

To prevent the acetone from sloshing around (A) Signup and view all the answers

Why is oxygen a powerful oxidizer?

Because it promotes vigorous combustion (B) Signup and view all the answers

What is the recommended pressure for acetylene supply to a welding or cutting torch?

Below 100 kPa (15 psi) (B) Signup and view all the answers

What is the primary difference between an oxyacetylene outfit and an arc welding process?

Welding speed (D) Signup and view all the answers

What is the purpose of the needle valve in the oxy-fuel torch?

To control the flow of oxygen and acetylene (C) Signup and view all the answers

What is the importance of keeping valve protection caps in place and hand-tight when the cylinder is not in use?

To prevent physical damage to the cylinders (D) Signup and view all the answers

Why is OFW no longer commonly used in boiler, pressure vessel, and pressure piping manufacturing?

Due to its slower welding speed (C) Signup and view all the answers

What is the primary reason why a weld joint can be weakened despite being well-executed?

The weld joint is not designed using sound engineering practice (A) Signup and view all the answers

What is the consequence of introducing gas pockets or solid impurities into the weld metal?

The weld metal becomes brittle and susceptible to cracking (A) Signup and view all the answers

What is the purpose of the laws stipulated by provinces in Canada regarding boilers, pressure vessels, and pressure piping?

To ensure the safety and durability of boilers, pressure vessels, and pressure piping (D) Signup and view all the answers

What is the result of physically distorting a structure through improper weld methods?

The structure becomes useless (B) Signup and view all the answers

What is the primary reason why a weld joint that is defective will not be strong enough for the service conditions it will encounter?

The weld joint is not strong enough to withstand the service conditions (D) Signup and view all the answers

What is the consequence of the heat from welding and flame cutting affecting the weld metal?

The weld metal becomes brittle and susceptible to cracking (D) Signup and view all the answers

What is the primary purpose of the application of pressure in the welding process?

To ensure the coalescence of metals (B) Signup and view all the answers

What is the primary characteristic of the filler metal used in non-fusion welding?

It has a lower melting point than the parent metal (C) Signup and view all the answers

What is the primary difference between the base metal and the filler metal?

The base metal is the parent metal, while the filler metal is the added material (B) Signup and view all the answers

What is the primary purpose of cleaning the parts before brazing or soldering?

To remove oxidation from the metal surfaces (C) Signup and view all the answers

What is the primary advantage of using copper for constructing heating boilers?

It is an excellent heat conductor (D) Signup and view all the answers

What is the primary purpose of the silver brazing process?

To build-up the weld deposit thickness (A) Signup and view all the answers

What is the primary characteristic of the brazing process?

It involves melting the filler metal (A) Signup and view all the answers

What is the primary purpose of the ASME Code Section IX?

To provide guidelines for constructing boilers and pressure vessels (B) Signup and view all the answers

What is the primary difference between the soldering and brazing processes?

Soldering is done at a lower temperature than brazing (C) Signup and view all the answers

What is the primary purpose of the flux in the non-fusion welding process?

To prevent oxidation of the metal surfaces (A) Signup and view all the answers

What is the primary reason why OFW is not commonly used for boiler, pressure vessel, and pressure piping manufacturing?

All of the above (D) Signup and view all the answers

What is the purpose of the oxygen cylinder in an oxyacetylene outfit?

To supply pressurized oxygen to the torch (C) Signup and view all the answers

What is the approximate temperature at which acetylene burns with atmospheric oxygen?

2500°C (B) Signup and view all the answers

What is the primary purpose of the needle valve in the oxy-fuel torch?

To regulate the flow of oxygen and acetylene (C) Signup and view all the answers

What is the recommended maximum pressure for acetylene supply to a welding or cutting torch?

100 kPa (B) Signup and view all the answers

What is the primary advantage of OFW over other welding processes?

It is more portable and does not require an external power source (A) Signup and view all the answers

What is the primary purpose of the porous filler material in the acetylene cylinder?

To prevent the acetone from sloshing around (C) Signup and view all the answers

What is the approximate temperature required to melt steel using OFW?

3300°C (A) Signup and view all the answers

Why is oxygen a powerful oxidizer?

Because it is highly reactive (D) Signup and view all the answers

What is the primary purpose of the valve protection caps on the cylinders?

To prevent the cylinders from being damaged (B) Signup and view all the answers

What is the primary reason why MPS gas is used instead of propane for soldering copper pipe in sizes up to two-inch?

Because MPS gas burns at a higher temperature and has a greater heating value (D) Signup and view all the answers

What is the primary difference between OFW and brazing?

The temperature reached during the process (B) Signup and view all the answers

What is the primary advantage of fusion welding over non-fusion welding?

Fusion welding produces a stronger weld joint (A) Signup and view all the answers

What is the purpose of the mixing chamber in the torch used for soldering?

To mix air and propane (B) Signup and view all the answers

What is the primary characteristic of non-fusion welding?

The parent metal is heated below its melting temperature (D) Signup and view all the answers

What is the purpose of cleaning the remaining flux from the surfaces after brazing or soldering?

To prevent corrosion of the parent metal (B) Signup and view all the answers

What is the primary difference between oxyacetylene and MPS gas?

The heating value of the gas (C) Signup and view all the answers

What is the purpose of the orifice in the torch used for soldering?

To regulate the flow of propane to the burner tip (D) Signup and view all the answers

What is the primary advantage of using oxyacetylene outfits for brazing?

They produce a higher flame temperature (D) Signup and view all the answers

What is the primary difference between forge welding and fusion welding?

The method of joining the metal pieces (A) Signup and view all the answers

What is the primary reason for using a pressure regulator in oxyacetylene welding and cutting?

To reduce the pressure of the gas to the required level (B) Signup and view all the answers

Why is it essential to keep the threads of the oxygen cylinder and regulator clean?

To prevent combustion of lubricants or other materials (C) Signup and view all the answers

What is the typical pressure range of oxygen regulators used for cutting thick steel?

0-2760 kPa (0-400 psi) (C) Signup and view all the answers

Why is a flashback arrestor fitting necessary in oxyacetylene welding and cutting?

To prevent explosive flashback (A) Signup and view all the answers

What is the primary limitation of oxyacetylene cutting?

It can only be used for ferrous metals (D) Signup and view all the answers

What is the purpose of the cutting handle valve in oxyacetylene cutting?

To permit high-pressure oxygen to jet from the cutting tip (C) Signup and view all the answers

Why are oxygen and acetylene regulators not interchangeable?

Because of differences in thread types (A) Signup and view all the answers

What is the minimum temperature required to cut steel using oxyacetylene cutting?

870°C (C) Signup and view all the answers

Why can't stainless steel be flame cut directly?

Because it forms heat-resistant oxides (A) Signup and view all the answers

What is the purpose of the shut-off valve and threaded cap on a gas cylinder?

To prevent gas leakage when not in use (A) Signup and view all the answers

What is the purpose of having different threads on oxygen and acetylene cylinders and regulators?

To prevent accidental connection of the oxygen regulator to the acetylene cylinder (B) Signup and view all the answers

Why should lubricating and penetrating oil not be used on the oxygen regulator or pressure gauge threads?

Because they can cause combustible materials to ignite (B) Signup and view all the answers

What is the purpose of the special flame arrestor fitting in the gas supplies to the torch?

To prevent explosive flash back (A) Signup and view all the answers

What is the purpose of the shut off valve and threaded cap on each gas cylinder?

To protect the valve when a gas pressure regulator is not attached (B) Signup and view all the answers

What is the significance of the colours of the hoses that supply oxygen and acetylene to the welding/brazing torch?

The green hose supplies oxygen and the red hose supplies acetylene (B) Signup and view all the answers

Why is it important to keep the oxygen cylinder and regulator threads clean?

To prevent combustible materials from igniting (B) Signup and view all the answers

What is the primary reason why stainless steel and aluminum cannot be flame cut?

They rapidly form heat-resistant oxides when exposed to flame. (B) Signup and view all the answers

What is the purpose of the waster plate in flame cutting stainless steel?

To allow the cutting torch to be applied to the mild steel plate. (D) Signup and view all the answers

What is the primary difference between DCEN and DCEP in SMAW?

The amount of heat energy concentrated in the electrode. (B) Signup and view all the answers

What is the main advantage of using prime-mover driven welding generators?

They are portable (B) Signup and view all the answers

What is the purpose of the coating on the electrode in SMAW?

To provide a shield for the weld puddle (B) Signup and view all the answers

What is the function of the transformer in a SMAW power supply?

To change the voltage and current from one set of values to another. (A) Signup and view all the answers

What is the significance of the letter 'E' on an SMAW electrode?

It indicates the electrode is suitable for electric arc welding (B) Signup and view all the answers

What is the primary reason why DC machines are preferred over AC machines in SMAW?

DC machines provide better control of the welding process. (D) Signup and view all the answers

What is the typical pressure of oxygen used to cut steel plate?

280 kPa (B) Signup and view all the answers

What is the meaning of the first two digits of an AWS certified welding electrode?

The minimum tensile strength of the wire core material (A) Signup and view all the answers

What is the purpose of selecting an electrode with a tensile strength at least as great as the parent material?

To ensure the weld has the same strength as the parent material (D) Signup and view all the answers

What is the primary advantage of using DCEN in SMAW?

It produces higher rates of weld deposition and faster welding speeds. (A) Signup and view all the answers

What is the significance of the digit that follows the tensile strength in an AWS electrode designation?

It indicates the weld position the rod may be used in (B) Signup and view all the answers

What is the primary limitation of oxyacetylene cutting?

It is not suitable for cutting aluminum and stainless steel. (A) Signup and view all the answers

What is the purpose of the cutting handle valve in oxyacetylene cutting?

To permit high-pressure oxygen to jet from the cutting tip. (B) Signup and view all the answers

What is the purpose of the slag coating on the weld puddle in SMAW?

To act as insulation against the air while cooling takes place (C) Signup and view all the answers

What is the difference between a combustible and a mineral-coated electrode in SMAW?

The type of coating used on the electrode (A) Signup and view all the answers

What is the primary difference between the power supply for SMAW and oxyacetylene cutting?

The power supply for SMAW is electrical, while oxyacetylene cutting uses gas. (C) Signup and view all the answers

What is the purpose of the electrode coverings in SMAW?

To aid in stabilizing and directing the arc (B) Signup and view all the answers

What is the significance of the four-digit code on an AWS certified welding electrode?

It indicates the minimum tensile strength of the wire core material (A) Signup and view all the answers

What is the primary advantage of GMAW over SMAW?

It is faster and cleaner (C) Signup and view all the answers

What is the purpose of the rutile coating on the SMAW electrode?

To provide a gaseous shield and a slag coating (D) Signup and view all the answers

What type of welding process is GTAW?

Fully manual arc welding process (B) Signup and view all the answers

What is the primary characteristic of GMAW that makes it faster than SMAW?

The use of a continuous consumable wire electrode (A) Signup and view all the answers

What is the purpose of the inert shielding gas in GTAW?

To protect the weld area from atmospheric contamination (C) Signup and view all the answers

What is the primary advantage of GTAW over other welding processes?

It gives the operator greater control over the weld (C) Signup and view all the answers

What is the primary limitation of GMAW?

It is rarely used outdoors (B) Signup and view all the answers

What is the purpose of the power supply in SMAW?

To connect the work piece cable and the electrode holder (A) Signup and view all the answers

What is the primary difference between GMAW and SMAW?

The speed of the welding process (C) Signup and view all the answers

What is the primary characteristic of SMAW?

It uses a mineral coating of rutile and iron (C) Signup and view all the answers

What is the primary function of the flux in the Submerged Arc Welding process?

To shield the arc from the atmosphere (C) Signup and view all the answers

What is the purpose of the flux in the weld joint after the welding process is complete?

To protect the weld from oxidation (A) Signup and view all the answers

What is the typical maximum current used in Submerged Arc Welding?

4000 amps (A) Signup and view all the answers

What is the primary purpose of Post-Weld Heat Treatment (PWHT)?

To relieve stresses in the weld metal (D) Signup and view all the answers

What is the term used to describe the process of making steel harder by heating and then quenching (rapidly cooling) it?

Heat treatment (A) Signup and view all the answers

What is the primary advantage of using Submerged Arc Welding (SAW) over manual or semi-automatic welding?

Neater and more uniform appearance (A) Signup and view all the answers

What is the function of the machine in Submerged Arc Welding (SAW)?

To control the rate of weld progression and filler material admission (A) Signup and view all the answers

What is the primary difference between the constant voltage and drooping voltage characteristics of Submerged Arc Welding machines?

The self-adjusting arc length (D) Signup and view all the answers

What is the purpose of the granular flux in Submerged Arc Welding (SAW)?

To shield the arc from the atmosphere (A) Signup and view all the answers

What is the primary advantage of using two electrodes simultaneously in Submerged Arc Welding (SAW)?

Increased flexibility (B) Signup and view all the answers

What is the primary reason why a hardened cutting tool becomes brittle?

Because it is quenched in water or oil (A) Signup and view all the answers

What is the Heat Affected Zone (HAZ) in a weld joint?

The area where the weld metal and adjacent parent metal are heated (B) Signup and view all the answers

What is the purpose of post weld heat treatment (PWHT) in welded boilers and pressure vessels?

To restore the ductility of the weld metal (D) Signup and view all the answers

What happens when a brittle material is subjected to stress?

It breaks without deforming (C) Signup and view all the answers

What is the purpose of preheating a weld joint?

To prevent rapid cooling of the HAZ (A) Signup and view all the answers

Why do blacksmiths reheat a hardened cutting tool to a lower temperature?

To restore its ductility (B) Signup and view all the answers

What is the result of quenching a heated steel?

It becomes harder and more brittle (C) Signup and view all the answers

What is the purpose of the ASME codes in relation to boilers and pressure vessels?

To provide regulations for the construction and maintenance of boilers and pressure vessels (D) Signup and view all the answers

What is the difference between a brittle and a ductile material?

A brittle material breaks without deforming, while a ductile material deforms before breaking (B) Signup and view all the answers

Why is it important to use post weld heat treatment (PWHT) in boilers and pressure vessels?

To prevent brittle fracture (C) Signup and view all the answers

What is the reason for having different threads on oxygen and acetylene cylinders and regulators?

To prevent accidental connection of oxygen to acetylene cylinder (A) Signup and view all the answers

Why is it crucial to keep the oxygen cylinder and regulator threads clean?

To prevent combustible materials from igniting (C) Signup and view all the answers

What is the purpose of the green and red hoses in an oxyacetylene setup?

To supply acetylene and oxygen to the torch (C) Signup and view all the answers

What is the function of a flashback arrestor fitting in an oxyacetylene setup?

To prevent explosive flashbacks (C) Signup and view all the answers

What is the purpose of the shut-off valve and threaded cap on a gas cylinder?

To protect the valve when a regulator is not attached (B) Signup and view all the answers

Why is it important to use the correct thread on an oxygen cylinder and regulator?

To prevent accidental connection of oxygen to acetylene cylinder (D) Signup and view all the answers

What is the primary purpose of the slag coating on the weld puddle in SMAW?

To protect the weld metal from atmospheric contamination (B) Signup and view all the answers

What is the primary characteristic of GMAW that makes it faster than SMAW?

The lack of need for a welder to intermittently stop and replace filler rods (A) Signup and view all the answers

What is the primary advantage of GTAW over other welding processes?

Its ability to provide greater control over the weld (D) Signup and view all the answers

What is the primary purpose of the electrode coating in SMAW?

To provide a gaseous shield (B) Signup and view all the answers

What is the primary characteristic of the weld produced by GMAW?

It is cleaner and faster than SMAW (D) Signup and view all the answers

What is the primary purpose of the shielding gas in GMAW?

To protect the weld metal from atmospheric contamination (A) Signup and view all the answers

What is the primary difference between GMAW and GTAW?

The type of electrode used (C) Signup and view all the answers

What is the primary purpose of the power supply in GMAW?

To provide a constant voltage, direct current (A) Signup and view all the answers

What is the primary characteristic of the GTAW process?

It is a fully manual arc welding process (B) Signup and view all the answers

What is the primary advantage of SMAW over other welding processes?

It is a more forgiving welding process for beginners (B) Signup and view all the answers

What is the primary reason why stainless steel cannot be flame cut directly?

It forms heat resistant oxides when exposed to flame (C) Signup and view all the answers

What is the function of the cutting handle valve in a cutting torch?

To control the flow of oxygen to the cutting tip (C) Signup and view all the answers

What is the primary advantage of prime-mover driven welding generators?

They are portable (A) Signup and view all the answers

What is the result of the electrical energy converted into heat when an electric current passes from the weld electrode to the parent material in the form of an arc?

The generation of heat energy (D) Signup and view all the answers

What is the primary difference between DCEN and DCEP in SMAW?

The amount of heat energy concentrated in the electrode (B) Signup and view all the answers

What is the purpose of the gaseous envelope produced by the combustible electrode coating in SMAW?

To protect the weld puddle from oxygen, hydrogen, and moisture (A) Signup and view all the answers

What is the purpose of the waster plate in cutting stainless steel?

To allow the cutting torch to cut the stainless steel (B) Signup and view all the answers

What is the significance of the letter 'E' on an SMAW electrode?

It indicates the electrode is suitable for electric arc welding (D) Signup and view all the answers

What is the primary reason why cast iron is more difficult to cut than mild steel?

It is more brittle (D) Signup and view all the answers

What is the purpose of the slag coating on the weld puddle in SMAW?

To act as insulation against the air while cooling takes place (C) Signup and view all the answers

What is the primary function of the transformer in a SMAW power supply?

To change voltage and current values (A) Signup and view all the answers

What is indicated by the first two digits of an AWS certified welding electrode?

The minimum tensile strength of the wire core material (A) Signup and view all the answers

What is the primary advantage of using DC machines in SMAW?

They provide better control of the welding process (A) Signup and view all the answers

What is the primary difference between mineral-coated and combustible-coated electrodes?

The way they protect the weld puddle (B) Signup and view all the answers

What is the typical application of welding generators mounted on a truck or trailer?

Remote pipeline use (B) Signup and view all the answers

What is the primary purpose of changing the oxygen pressure in oxyacetylene cutting?

To suit the thickness of the plate being cut (C) Signup and view all the answers

What is the primary reason why oxyacetylene cutting is often referred to as ‘flame cutting’?

Because it is inaccurate (B) Signup and view all the answers

What is the purpose of the electrode coating in SMAW?

To protect the weld puddle and stabilize the arc (D) Signup and view all the answers

What is the significance of the digit that follows the tensile strength in an AWS certified welding electrode?

It indicates the type of welding position the electrode can be used in (D) Signup and view all the answers

What is the primary advantage of using DC welding over AC welding?

It is preferred by industrial welders (A) Signup and view all the answers

What is the primary purpose of the flux in Submerged Arc Welding (SAW)?

To provide a path for the current (D) Signup and view all the answers

What is the result of the molten flux rising to the surface of the weld in SAW?

It solidifies as a glass-like covering for the weld bead (A) Signup and view all the answers

What is the primary advantage of using Submerged Arc Welding (SAW) over manual or semi-automatic welding?

It is faster and more efficient (D) Signup and view all the answers

What is the purpose of post-weld heat treatment (PWHT)?

To relieve internal stresses in the weld metal (D) Signup and view all the answers

What is the term used to describe the process of making steel harder by heating and then quenching (rapidly cooling) it?

Quenching (B) Signup and view all the answers

What is the primary difference between the electric arc in SAW and other arc welding processes?

The arc is shielded by a granular flux (C) Signup and view all the answers

What is the purpose of the valve protection caps on the cylinders?

To protect the valve from damage (C) Signup and view all the answers

What is the primary difference between DC and AC current in SAW?

DC is used for welding with a constant voltage, while AC is used for welding with a drooping voltage (C) Signup and view all the answers

What is the purpose of the steel wool in starting the arc in SAW?

To facilitate the ignition of the arc (A) Signup and view all the answers

What is the primary advantage of using multiple electrodes in SAW?

It increases the welding speed (D) Signup and view all the answers

What is the primary reason why a weld joint becomes hard and brittle after welding?

Due to rapid cooling of the heat affected zone (B) Signup and view all the answers

What is the purpose of post-weld heat treatment in welding boilers and pressure vessels?

To relieve the stresses in the weld joint (D) Signup and view all the answers

What is the effect of rapid cooling on the heat affected zone during welding?

It makes the weld joint more brittle (D) Signup and view all the answers

What is the purpose of preheating the weld joint during welding?

To reduce the temperature gradient between the heat affected zone and the parent metal (D) Signup and view all the answers

What is the result of tempering a hardened cutting tool?

It becomes more ductile (D) Signup and view all the answers

What is the primary reason why boilers and pressure vessels are prone to sudden failures?

Due to the brittle nature of the weld joints (C) Signup and view all the answers

What is the purpose of the ASME codes in relation to boilers and pressure vessels?

To provide guidelines for welding and fabrication (D) Signup and view all the answers

What is the effect of quenching on the hardness of steel?

It makes the steel harder (D) Signup and view all the answers

What is the primary advantage of using post-weld heat treatment in welding boilers and pressure vessels?

It increases the ductility of the weld joint (A) Signup and view all the answers

What is the purpose of heating the entire weld joint to a specific temperature during post-weld heat treatment?

To restore the ductility of the weld joint (B) Signup and view all the answers

What is the main characteristic of fillet welds?

They have parent material behind the weld puddle. (B) Signup and view all the answers

What is the purpose of the small short welds in a groove weld?

To hold the work pieces in position while the material is being welded. (C) Signup and view all the answers

What type of joint is used to attach nozzles and firetube tubesheets to boiler shells?

Tee joint (A) Signup and view all the answers

What is the advantage of fillet welds over groove welds?

They are easier to perform because they have backing material. (D) Signup and view all the answers

What is the purpose of machining the edges of the work pieces in a groove weld?

To ensure the edges are smooth and match in contour. (A) Signup and view all the answers

What is the characteristic of a butt joint?

It connects work pieces that have their thicknesses centered in-line. (C) Signup and view all the answers

What is the term used to describe a weld joint that is welded from both sides?

Double-welded (B) Signup and view all the answers

What is the purpose of the root face in a groove weld?

To provide additional parent material at the root (B) Signup and view all the answers

What is the minimum requirement for the weld joint according to ASME 1 PW-9.1?

Full penetration butt welds (D) Signup and view all the answers

What is the purpose of machining the weld joint surfaces?

To achieve full penetration (D) Signup and view all the answers

What is the most common form of weld preparation used for welding lengths of high-pressure pipe?

V-groove (B) Signup and view all the answers

What is the term used to describe the distance the root extends to the back side of the parent metal?

Root penetration (D) Signup and view all the answers

What is the purpose of cleaning the weld surface after each pass?

To remove slag particles (D) Signup and view all the answers

What is the result of inadequate weld joint preparation?

Poor quality root pass (B) Signup and view all the answers

What is the advantage of using double-welded joints compared to single-welded joints of the same thickness?

Reduced parent material distortion (B) Signup and view all the answers

What is the term used to describe the process of the weld metal joining with the parent metal?

Fusion (C) Signup and view all the answers

What is the primary purpose of a strength weld in a pressure vessel?

To ensure the vessel's integrity and safety (C) Signup and view all the answers

What is the significance of a certified pressure welder in boiler and pressure vessel construction?

They have thousands of hours of documented welding time and have passed a welding performance test (A) Signup and view all the answers

What type of joints are welded from one side of the parent metal in a double-welded joint?

Passes 1-7 (D) Signup and view all the answers

What is the purpose of a seal weld in a boiler or pressure vessel?

To prevent leakage (D) Signup and view all the answers

What is the primary characteristic of a welded joint in a pressure vessel?

It is as strong as the parent metal (A) Signup and view all the answers

What is the purpose of the ASME code in relation to boilers and pressure vessels?

To ensure the vessel's integrity and safety through welding and fabrication procedures (A) Signup and view all the answers

What is the primary purpose of staybolts in a boiler?

To support flat surfaces in close proximity to one another (D) Signup and view all the answers

What is the significance of the coupons in a welding performance test?

They are used to test the weld joint's integrity (D) Signup and view all the answers

What is the purpose of the seal welds applied to expanded tube attachments in a boiler?

To prevent leakage (B) Signup and view all the answers

What type of welds are critical to the strength, safety, and longevity of a boiler?

Pressure boundary welds (C) Signup and view all the answers

What is the primary purpose of a nozzle attachment in a boiler or pressure vessel?

To attach fittings or piping (A) Signup and view all the answers

What is the purpose of the weld beads applied to handhole openings in a high-pressure boiler?

To prevent leakage (C) Signup and view all the answers

What is the significance of modern quality assurance procedures in welded fabrication?

They are used to ensure the vessel's integrity and safety (B) Signup and view all the answers

What is the purpose of the pressure boundary seal welds in welded fin tube waterwall panels?

To prevent flue gas, ash, and soot leakage (D) Signup and view all the answers

What is the purpose of the lifting lugs welded to the top of the steam drum in a boiler?

To enable easy transportation and installation (C) Signup and view all the answers

What is the purpose of the manhole flue welded to the front head of the steam drum in a boiler?

To enable easy access for inspection and maintenance (D) Signup and view all the answers

What is the purpose of the manhole flue in a boiler?

All of the above (D) Signup and view all the answers

What type of weld is used to secure the tube stub in place when attaching tubes to a header?

Groove weld (C) Signup and view all the answers

What is the purpose of a repad in a pressure vessel?

To stiffen the area of the shell weakened by the hole (A) Signup and view all the answers

What is the purpose of stays and staybolts in a boiler?

To prevent flat boiler or pressure vessel surfaces from bulging due to the effects of pressure (A) Signup and view all the answers

What type of weld is used to attach a manhole flue to a shell?

Full penetration groove weld (B) Signup and view all the answers

What is the purpose of a diagonal stay in a firetube boiler?

To tie flat surfaces to other supporting structures (B) Signup and view all the answers

What is the purpose of a through stay in a firetube boiler?

To provide additional support for the water-wetted tubesheet surfaces (D) Signup and view all the answers

What is the purpose of the ASME code in relation to boilers and pressure vessels?

To provide guidelines for the fabrication and installation of boilers and pressure vessels (A) Signup and view all the answers

What is the purpose of a handhole in a boiler?

To provide access to smaller parts, such as headers and waterlegs (A) Signup and view all the answers

What type of weld is used to attach a staybolt to a boiler?

Fillet weld (B) Signup and view all the answers

What is the primary advantage of having backing material in fillet welds?

It prevents the heat of the arc from burning through the parent metal. (D) Signup and view all the answers

What is the purpose of machining the edges of parent metal pieces before making a groove weld?

To smooth the edges and match them in contour. (A) Signup and view all the answers

What type of joint is used to attach nozzles and firetube tubesheets to boiler shells?

Tee joint (C) Signup and view all the answers

What is the purpose of making small short welds to hold the work pieces in position during groove welding?

To hold the work pieces in position while being welded. (C) Signup and view all the answers

What is the primary difference between groove welds and fillet welds?

The presence of backing material. (C) Signup and view all the answers

What is the purpose of setting the work pieces apart by the approximate thickness of the welding rod during groove welding?

To allow for the correct size of the weld puddle. (C) Signup and view all the answers

What is the purpose of the weld bead in Figure 29?

To help prevent leakage between the handhole and the boiler shell (C) Signup and view all the answers

What is the primary purpose of the seal welds in Figure 28?

To prevent leakage between the tube and the shell (C) Signup and view all the answers

What is the purpose of the manhole flue in the front head of the steam drum shown in Figure 27?

To provide access to the drum for maintenance (A) Signup and view all the answers

What is the purpose of the lifting lugs on the top of the steam drum shell in Figure 27?

To enable the drum to be lifted during transportation and installation (A) Signup and view all the answers

What is the purpose of the riser tube stubs on the side of the steam drum in Figure 27?

To connect the drum to the tubes of the boiler (B) Signup and view all the answers

What is the purpose of the pressure boundary seal welds in the waterwall panels shown in Figure 31?

To prevent flue gas, ash, and soot leakage from the furnace into the boiler room (C) Signup and view all the answers

What is the purpose of the manhole flue in a boiler?

To reinforce the shell where the manhole opening is and provide a flat surface for the manhole cover plate to seal against (D) Signup and view all the answers

What is the purpose of the repad in the vessel shown in Figure 24?

To provide additional reinforcement to the shell (C) Signup and view all the answers

What is the purpose of the tell-tale hole in the repad?

To show if the pressure vessel weakens and fails beneath the repad (A) Signup and view all the answers

What type of welds are used to secure the tube stub in place?

Groove welds (C) Signup and view all the answers

What is the purpose of the stays in a boiler?

To prevent flat boiler or pressure vessel surfaces from bulging due to the effects of pressure (C) Signup and view all the answers

What is the purpose of the through stays in a firetube boiler?

To provide support for the water-wetted tubesheet surfaces (A) Signup and view all the answers

How are the stays typically fastened to the tubesheets?

By welding (B) Signup and view all the answers

What is the purpose of the yoke in a boiler?

To hold the cover plate in place (B) Signup and view all the answers

What type of welds are used to attach the manhole flue to the shell?

Full penetration groove welds (A) Signup and view all the answers

What is the purpose of the handholes in a boiler?

To provide access to smaller parts such as headers and waterlegs (A) Signup and view all the answers

What is the primary purpose of the root face in a weld groove?

To provide additional parent material at the root (B) Signup and view all the answers

What is the consequence of not achieving full penetration in a weld joint?

The weld joint will have a poor quality root, affecting its integrity (D) Signup and view all the answers

What is the purpose of the 'V-groove' weld preparation?

To allow for single-sided welding of thick materials (D) Signup and view all the answers

What is the primary purpose of a certified pressure welder in the fabrication or repair of a boiler or pressure vessel?

To perform all weld joints on the pressure boundary of the vessel (A) Signup and view all the answers

What is the advantage of using double-welded joints over single-welded joints for thicker materials?

They reduce parent material distortion and residual stress (D) Signup and view all the answers

What is theterm for the metal components that directly restrain forces that arise due to the vessel’s internal pressure?

Pressure boundary (B) Signup and view all the answers

What is the purpose of machining the weld joint surfaces in a double-welded joint?

To facilitate welding from both sides (A) Signup and view all the answers

What is the purpose of the groove angle in a weld preparation?

To ensure full penetration of the weld metal (B) Signup and view all the answers

What is the typical method of attaching nozzles to shells and headers in a boiler or pressure vessel?

Welded attachments (D) Signup and view all the answers

What is the result of inadequate fusion in a weld joint?

The weld joint will have a weak bond between the weld metal and the parent metal (A) Signup and view all the answers

What is the purpose of cleaning the weld surface after each pass?

To remove slag particles and prevent them from being embedded in subsequent passes (A) Signup and view all the answers

What is the primary advantage of using modern welded fabrication techniques in constructing boilers and pressure vessels?

They can produce joints that are as strong as, if not stronger than, the parent material (A) Signup and view all the answers

What is the term used to describe the distance the root extends to the back side of the parent metal?

Root penetration (C) Signup and view all the answers

What is the purpose of the x-ray test in the certification process of a pressure welder?

To inspect the internal structure of the weld joint (D) Signup and view all the answers

What is the purpose of the root pass in a weld joint?

To fuse the metal at the root of the joint (D) Signup and view all the answers

What is the term for the type of weld joint that is designed to be as strong as the parent material?

Strength weld (A) Signup and view all the answers

What is the purpose of the welding performance test in the certification process of a pressure welder?

To evaluate the welder's ability to follow a specific procedure (D) Signup and view all the answers

What is the consequence of not having adequate inter-pass fusion in a weld joint?

The weld joint will have a lack of strength between subsequent passes (B) Signup and view all the answers

What is the primary purpose of the ASME code in the construction of boilers and pressure vessels?

To provide guidelines for the fabrication of boilers and pressure vessels (B) Signup and view all the answers

What is the term for the process of attaching nozzles or fittings to the shell or header of a boiler or pressure vessel?

Attachments (C) Signup and view all the answers

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Questions and Answers

What is a potential consequence of poor welding technique?

What can occur when the heat from welding and flame cutting affects the weld metal?

Why is it important to design a weld joint using sound engineering practice?

What is the purpose of the ASME Code Section IX?

What is the consequence of a defective weld joint?

Why do provinces in Canada have laws stipulating that boilers, pressure vessels, and pressure piping be made in accordance with ASME Code Section IX?

What is the definition of welding according to ASME IX?

What is the main difference between non-fusion and fusion welding?

What is the role of flux in the non-fusion welding process?

What is the primary difference between brazing and soldering?

Which of the following is NOT a characteristic of non-fusion welding?

What is the typical temperature range for soldering?

What is the primary advantage of using brazing for constructing copper heating boilers?

What is the purpose of ensuring the parts fit properly before brazing or soldering?

What is the difference between silver brazing and regular brazing?

What is the primary purpose of heat in the non-fusion welding process?

What is the approximate pressure of a fully charged oxygen cylinder?

What is the purpose of a pressure regulator in oxyacetylene welding and cutting?

Why are oxygen and acetylene regulators not interchangeable?

What is the typical colour of the hose that supplies oxygen to the welding/brazing torch?

What is the minimum temperature required to cut steel using oxyacetylene cutting?

What is the purpose of a flashback arrestor in oxyacetylene welding and cutting?

What is the typical pressure of oxygen used to cut steel plate?

Why can't stainless steel be flame cut directly?

What is the purpose of the cutting handle valve in oxyacetylene cutting?

What is the approximate pressure of a fully charged acetylene cylinder?

What is the primary difference between brazing and soldering?

Which type of gas is used for brazing or very large soldered joints?

What is the purpose of flux in brazing and soldering?

What is the primary characteristic of fusion welding?

Which type of welding is no longer used for industrial purposes due to weak weld joints?

What is the term for the fuel used in OFW processes?

What is the primary difference between OFW and brazing?

What is the purpose of a hand torch in soldering?

What is the term for the equipment used for brazing and soldering?

Why is MPS gas used for soldering copper pipe?

What is the primary advantage of OFW over other welding processes?

What is the approximate temperature at which acetylene burns with pressurized oxygen?

Why is acetylene dissolved in liquid acetone in the cylinder?

What is the purpose of the porous filler material in the acetylene cylinder?

Why is oxygen a powerful oxidizer?

What is the recommended pressure for acetylene supply to a welding or cutting torch?

What is the primary difference between an oxyacetylene outfit and an arc welding process?

What is the purpose of the needle valve in the oxy-fuel torch?

What is the importance of keeping valve protection caps in place and hand-tight when the cylinder is not in use?

Why is OFW no longer commonly used in boiler, pressure vessel, and pressure piping manufacturing?

What is the primary reason why a weld joint can be weakened despite being well-executed?

What is the consequence of introducing gas pockets or solid impurities into the weld metal?

What is the purpose of the laws stipulated by provinces in Canada regarding boilers, pressure vessels, and pressure piping?

What is the result of physically distorting a structure through improper weld methods?

What is the primary reason why a weld joint that is defective will not be strong enough for the service conditions it will encounter?

What is the consequence of the heat from welding and flame cutting affecting the weld metal?

What is the primary purpose of the application of pressure in the welding process?

What is the primary characteristic of the filler metal used in non-fusion welding?

What is the primary difference between the base metal and the filler metal?

What is the primary purpose of cleaning the parts before brazing or soldering?

What is the primary advantage of using copper for constructing heating boilers?

What is the primary purpose of the silver brazing process?

What is the primary characteristic of the brazing process?

What is the primary purpose of the ASME Code Section IX?

What is the primary difference between the soldering and brazing processes?

What is the primary purpose of the flux in the non-fusion welding process?

What is the primary reason why OFW is not commonly used for boiler, pressure vessel, and pressure piping manufacturing?

What is the purpose of the oxygen cylinder in an oxyacetylene outfit?

What is the approximate temperature at which acetylene burns with atmospheric oxygen?

What is the primary purpose of the needle valve in the oxy-fuel torch?

What is the recommended maximum pressure for acetylene supply to a welding or cutting torch?

What is the primary advantage of OFW over other welding processes?

What is the primary purpose of the porous filler material in the acetylene cylinder?

What is the approximate temperature required to melt steel using OFW?

Why is oxygen a powerful oxidizer?

What is the primary purpose of the valve protection caps on the cylinders?

What is the primary reason why MPS gas is used instead of propane for soldering copper pipe in sizes up to two-inch?

What is the primary difference between OFW and brazing?

What is the primary advantage of fusion welding over non-fusion welding?

What is the purpose of the mixing chamber in the torch used for soldering?