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Mississippi Welding

Mississippi  ·  PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
60
Passing score
70%
Exam time
120 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

Mississippi State Portion 60 questions

Oxyacetylene Welding and Cutting 11 Q · 18%
Oxyacetylene welding equipment components and assemblyWelding flame types and adjustment (neutral, carburizing, oxidizing)Cylinder safety, handling, and storagePressure regulators, gauges, and hose fittingsTorch startup, shutdown, and leak testing proceduresBackfire and flashback causes and preventionOxyfuel gas cutting process, tips, and working pressuresWelding joint types, positions, and quality inspection
Blueprint and Plan Reading 6 Q · 10%
AWS welding symbols and their components (reference line, arrow, tail, weld symbol)Five basic weld joint types (butt, lap, corner, T-joint, edge)Welding positions and AWS position designations (1G/2G/3G/4G, 1F/2F/3F/4F)Reading groove weld dimensions (root opening, groove angle, depth of bevel, groove weld size)Fillet weld size, leg, and throat dimensionsOrthographic projection and multiview drawing interpretationLine types on mechanical drawings (object, hidden, centerline, dimension, extension, cutting plane, section, leader lines)Title block information and drawing scale
Brazing 5 Q · 8%
Brazing vs. braze welding definitions and principles (capillary action, temperature requirements, AWS definitions)Joint design and clearance for brazing and braze welding (fit-up, joint types, dissimilar metal expansion)Base metal cleaning methods (chemical cleaning, mechanical cleaning, pickling, degreasing)Flux selection, composition, and application methods (AWS classifications, forms, application techniques)Brazing filler metal selection by base metal combination (AWS classifications, solidus/liquidus temperatures, service temperatures)Torch tip selection, flame adjustment, and working pressures for brazing and braze weldingStep-by-step brazing and braze welding procedure (heat application, filler metal addition, joint cleaning)Safety precautions and health hazards (cadmium/beryllium fumes, ventilation, PPE, toxic flux handling)
Pipe Welding 6 Q · 10%
Pipe joint preparation (beveling, root face, root opening dimensions)Welding positions for pipe (1G, 2G, 5G, 6G) and directional techniques (uphill vs. downhill)Root pass welding techniques and keyhole methodIntermediate and cover pass procedures (pass sequence, electrode selection, weave patterns)GTAW root bead welding process and equipmentPipe fit-up, alignment tools, tack welding, and featheringPipe welding defects (causes, prevention, and repair)Welder and procedure qualification standards (ASME, API 1104)
Materials 10 Q · 17%
Ferrous metal classification and carbon content rangesPhysical and mechanical properties of metals (tensile strength, ductility, hardness, toughness, brittleness)Iron-carbon phase diagram and microstructural constituents (ferrite, pearlite, austenite, martensite, cementite)SAE/AISI/ASTM steel numbering systemsStainless steel types and weldability characteristicsNonferrous metals and alloys (aluminum, copper, brass, bronze, titanium) and their welding considerationsHeat treatment processes (annealing, normalizing, quenching and tempering, stress relieving)Metal identification methods (spark test, torch test, fracture test, magnetic test)
SMAW 9 Q · 15%
SMAW equipment components and power source types (AC, DC, inverter, engine-driven)Electrode classification system (AWS numbering, covering types, polarity, position designations)Current and polarity selection (DCEN, DCEP, AC) and effects on penetration and depositionArc striking, arc length control, and travel/work angle techniquesWeld bead types and electrode motion (stringer, weave, whip-and-pause, Z-weave)Weld defects and quality inspection (undercut, porosity, slag inclusion, overlap, incomplete fusion)Multiple-pass pipe welding procedures (root pass, intermediate passes, cover pass)Electrode storage, handling, and reconditioning (low-hydrogen electrode care, drying ovens)
GTAW 9 Q · 15%
Current polarity selection (DCEN, DCEP, AC) and effects on penetration and cleaning actionTungsten electrode types, color codes, and preparation methodsShielding gas selection and flow rate settingsGTAW equipment setup including power source controls, torch assembly, and remote current controlWelding techniques for joint types in all positionsRoot bead welding procedure for pipe using GTAWPulsed arc GTAW and special current features (upslope, downslope)GTAW troubleshooting and weld defect identification
Testing and Inspection 4 Q · 7%
Nondestructive examination (NDE) methods (visual, magnetic particle, liquid penetrant, ultrasonic, radiographic, eddy current)Destructive testing methods (bend, tensile, nick break, peel, impact, hardness, macroetch)Welding procedure specification (WPS) purpose, variables, and categories (qualified, prequalified, standard)Procedure qualification record (PQR) requirements and documentationWelder performance qualification testing (positions, specimens, acceptance criteria)Common pipe welding defects and their causes (porosity, slag inclusions, undercutting, cracking, lack of fusion)Essential versus nonessential welding variables and conditions requiring requalificationWelding codes and standards (AWS, ASME, API) and their jurisdictional scope

Key Distinctions

Two-stage acetylene regulator (first stage)vsTwo-stage oxygen regulator (first stage)

The acetylene regulator's first stage drops cylinder pressure to about 50 psig (350 kPa), while the oxygen regulator's first stage drops it to about 200 psig (1400 kPa) before the second stage takes it to working pressure.

Modern Welding (12th ed.), Chapter 12 — Oxyfuel Gas Welding Equipment and Supplies, Section 12.4.3
Acetylene hose fitting nutvsOxygen hose fitting nut

The acetylene nut has a groove machined around its six sides and left-hand threads, while the oxygen nut has flat, smooth sides and right-hand threads, preventing cross-connection.

Modern Welding (12th ed.), Chapter 12 — Oxyfuel Gas Welding Equipment and Supplies, Section 12.5
BackfirevsFlashback

A backfire is a momentary pop often caused by gas flowing too slowly for the tip size (corrected by slightly increasing oxygen and acetylene working pressures), whereas a flashback is a sustained backfire that burns back through the torch into the hoses and possibly the regulators.

Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.2.9
BrazingvsBraze welding

AWS defines brazing as distributing filler metal between closely fitted faying surfaces by capillary action; braze welding does not rely on capillary action.

Modern Welding (12th ed.), Chapter 17 Brazing and Braze Welding, Section 17.1
BrazingvsSoldering

Both use capillary action, but brazing uses filler metal with a liquidus above 840°F (450°C) and soldering is done below 840°F (450°C).

Modern Welding (12th ed.), Chapter 17 Brazing and Braze Welding, Section 17.1
Arrow-side weld informationvsOther-side weld information

On an AWS welding symbol, arrow-side information is always placed below the reference line and other-side information always above it.

Modern Welding (12th ed.), Chapter 3, Section 3.5.3
S position on a welding symbolvsE position on a welding symbol

S (first number left of the symbol) gives the depth of bevel/depth of preparation, while E gives the groove weld size shown in parentheses; if no groove weld size is shown for a single- or double-groove weld, complete joint penetration is required.

Modern Welding (12th ed.), Chapter 3, Section 3.5.6
Root pass restart on pipevsIntermediate pass restart on pipe

For an intermediate pass the arc is struck 3/8" (10 mm) in front of the crater and then moved back into it, whereas the root pass restart strikes the arc 3/8" back on the existing bead.

Modern Welding (12th ed.), Page 23-27
Neutral / oxidizing / carburizing flame (weld pool appearance)vs—

A neutral flame gives a smooth, glossy weld pool; an oxidizing flame makes the pool bubble and spark excessively; a carburizing (reducing) flame makes it dull and dirty (sooty).

Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.3.2
Austenitic stainless steelvsFerritic and martensitic stainless steel

Austenitic stainless is not magnetic (a magnet will not attract it), while ferritic and martensitic grades are magnetic.

Modern Welding (12th ed.), Chapter 28
BronzevsBrass

Bronze is a copper-tin alloy (commonly 88% copper, 12% tin), while brass is a copper-zinc alloy.

Modern Welding (12th ed.), Chapter 22 (Special Nonferrous Welding Applications)
Uphill pipe welding groove anglevsDownhill pipe welding groove angle

Uphill-completed pipe welds typically use a 75° groove angle (37.5° bevel per pipe); downhill welding uses a narrower 60° groove angle.

Modern Welding, Page 23-6; Pipe Welding Procedures, Chapter 4
Prequalified and Standard WPSvsQualified WPS

Prequalified WPSs (per AWS D1.1 Clause 3) and AWS Standard WPSs require no supporting PQR; only a qualified WPS requires a PQR documenting successful testing.

Modern Welding (12th ed.), Chapter 31, Section 31.2
SpheroidizingvsAnnealing / normalizing

Spheroidizing heats high-carbon steel to just below the A₁ lower critical temperature to form cementite spheres and improve ductility, while annealing and normalizing heat above the A₃ critical temperature.

Modern Welding (12th ed.), Chapter 29, Section 29.4.5 (Spheroidizing)

Key Terms

Flashback Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.2.9
A sustained backfire that continues burning back through the torch and into the hoses and potentially the regulators; shut off the torch oxygen valve first, then the fuel gas torch valve, then both cylinder valves.
Flashback arrestor Modern Welding (12th ed.), Chapter 12 — Oxyfuel Gas Welding Equipment and Supplies, Section 12.6
A safety device with a heat-sensitive check valve that stops gas flow, and which cannot be reused after a sustained flashback or after reaching 220°F (104°C).
Cracking the valve Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.2.1
Quickly opening a cylinder valve slightly and closing it to blow high-pressure gas through the outlet and remove dirt and particles before attaching regulators.
Keyhole welding procedure Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.4.1
An oxyacetylene butt-joint technique in which filler metal is added only once a keyhole shape appears at the leading edge of the weld pool, ensuring 100% penetration.
Travel angle (OFW) Modern Welding (12th ed.), Oxyfuel Gas Welding, Section 13.3.1
The 35°–45° angle between the torch axis and a line perpendicular to the weld axis used when creating a continuous weld pool.
"C"-shaped weld pool Modern Welding (12th ed.), Oxyfuel Gas Welding, Sections 13.4.2 and 13.4.4
The pool shape that confirms both pieces of a lap joint (or inside corner joint) are molten before filler metal is added.
Overlap Modern Welding (12th ed.), Chapter 6, Page 143
Unfused weld metal lying on the base metal at the weld toe, caused by insufficient heat from too short an arc length, which also produces a high bead with poor penetration.
Fillet weld leg Modern Welding (12th ed.), Chapter 3, Section 3.1 (Fillet Weld discussion near Figure 3-8)
The shortest distance from the toe to the surface of the other piece of base metal; fillet weld size is the length of one side and the effective throat is the minimum distance from the weld face to the root.
Cutting plane line Modern Welding (12th ed.), Chapter 2, Section 2.4.5
The thickest line type on a drawing, made of 3/4" long lines alternating with pairs of 1/8" short dashes; whenever used, a section view must appear on the print.
Hidden edge line Modern Welding (12th ed.), Chapter 2, Section 2.4.1
A line of 1/8" (3 mm) dashes spaced 1/16" (1.5 mm) apart representing edges and features hidden behind material in front of them.
Section lines Modern Welding (12th ed.), Chapter 2, Section 2.4.6
Thin lines drawn at 45° to the object lines to show solid cutaway surfaces in a section view; adjacent parts use opposite directions and different styles can indicate different materials.
Pearlite Modern Welding (12th ed.), Chapter 28
A layered microstructure of ferrite and cementite that always contains 0.77% carbon and forms at 1341°F (727°C) at the eutectoid point.
Spheroidizing Modern Welding (12th ed.), Chapter 29, Section 29.4.5 (Spheroidizing)
A heat treatment that improves ductility of high-carbon steel by forming cementite into small spheres, heating to just below the A₁ critical temperature and holding.
FB3-A flux Modern Welding (12th ed.), Chapter 17 Brazing and Braze Welding, Section 17.4
An AWS paste brazing flux with an activity range of 1050°F–1600°F (565°C–870°C) for steels, copper, copper alloys, nickel, and nickel alloys.
BCuP (copper-phosphorus) filler metal Modern Welding (12th ed.), Chapter 17 Brazing and Braze Welding, Section 17.5
Filler used on copper, copper alloys, silver, tungsten, and molybdenum; it must not be used on ferrous metals, nickel-based alloys, or copper-nickel alloys over 10% nickel.
Performance essential variable (AWS D1.1) Modern Welding (12th ed.), Chapter 31, Section 31.4
A change requiring welder requalification, such as changing weld progression from uphill to downhill or downhill to uphill; a change in amperage within the manufacturer's recommended range is a nonessential variable for SMAW.
Nickel root face Modern Welding (12th ed.), Page 23-11
A 3/32 in (2.4 mm) root face, about the thickness of a nickel, versus a dime root face of 1/16 in (1.6 mm).
1G flat groove position Modern Welding (12th ed.), Chapter 3, Section 3.4.1
A groove weld with the weld axis within 15° of horizontal and the weld face within 30° of horizontal, welded from the upper side of the joint.

Formulas to Know

Theoretical throat of an equal-leg fillet weldthroat = 0.707 × leg size (e.g., 0.707 × 0.3125 in = 0.221 in; 0.707 × 0.5000 in = 0.353 in; 0.707 × 0.1875 in = 0.133 in)
Number of intermittent weld segments along a jointsegments = 1 + (joint length − segment length) ÷ pitch, rounded down (e.g., 1 + (42 − 3) ÷ 8 = 5)
Total weld length for intermittent welds on one sidetotal length = number of segments × segment length (e.g., 5 × 3 in = 15 in)
Unwelded space between intermittent weld segmentsspacing = pitch − segment length (pitch is center-to-center); e.g., 8 − 3 = 5 in; 4 − 2 = 2 in
Groove weld penetration as a percent of plate thickness (single side)% = E ÷ T, where E is the groove weld size in parentheses (e.g., 5/16 ÷ 1 = 31%; 5/16 ÷ 3/8 = 83%; 5/16 ÷ 1/2 = 62%; 5/16 ÷ 3/4 = 42%)
Unwelded root remaining after welding both sidesunwelded = T − (2 × E); e.g., 1 in − 2(5/16) = 3/8 in; 3/8 in − 2(5/16) = 0 (complete joint penetration); 3/4 in − 2(5/16) = 1/8 in
Unwelded root remaining after welding one sideunwelded = T − E; e.g., 1/2 in − 5/16 in = 3/16 in
Bevel angle prepared on each plate of a V-grooveper-plate bevel = included groove angle ÷ 2 (60° ÷ 2 = 30°; 45° ÷ 2 = 22.5°)
Bevelled height of a pipe jointbevelled height = wall thickness − root face (e.g., 0.500 − 0.0938 = 0.406 in)
Groove width at the pipe outside surface at fit-upwidth = root opening + 2 × (bevelled height × tan 35°) (e.g., 0.1250 + 2 × (0.406 × 0.7) = 0.694 in)
Maximum working pressure allowed on a regulator gaugemax reading = 2/3 × maximum dial calibration (e.g., a 300 psig gauge → 200 psig maximum working reading)
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