Welding Safety & Quality Control Flashcards

Per ANSI Z49.1 and NFPA 51B, combustible materials that cannot be protected should be relocated at least how far from a hot work location?

Answer: 35 ft (11 m)

The 35 ft (11 m) rule is the standard radius for removing or protecting combustibles around hot work.

Under OSHA 1910.253, stored oxygen cylinders must be separated from fuel-gas cylinders by a minimum of 20 ft or by a noncombustible barrier of what height?

Answer: 5 ft

OSHA requires 20 ft separation or a noncombustible barrier at least 5 ft high with a half-hour fire-resistance rating.

Acetylene should never be used at a withdrawal pressure exceeding which value?

Answer: 15 psig

Above 15 psig, acetylene becomes unstable and can decompose explosively.

According to the AWS F2.2 lens shade selector, what is the suggested shade number for SMAW using a 3/16 in. electrode?

Answer: Shade 12

For 5/32–1/4 in. electrodes, the minimum shade is 10 and the suggested comfort shade is 12.

Under AWS D1.1, which party is responsible for qualifying the WPSs and the welding personnel used on the job?

Answer: The Contractor

D1.1 puts responsibility for WPS and welder qualification on the Contractor, while the Engineer may accept or require verification.

A CWS needs to check welds on an austenitic stainless steel pressure line for surface cracks; which NDE method is NOT suitable?

Answer: Magnetic particle testing

Austenitic stainless steel is nonferromagnetic, so magnetic particle testing cannot produce indications.

What is the OSHA permissible exposure limit (8-hr TWA) for hexavalent chromium, a common hazard when welding stainless steel?

Answer: 5 µg/m³

OSHA 1910.1026 sets the hexavalent chromium PEL at 5 µg/m³ as an 8-hour TWA.

OSHA considers a confined-space atmosphere oxygen-deficient when oxygen content falls below what level?

Answer: 19.5%

Below 19.5% oxygen the atmosphere is oxygen-deficient and hazardous.

Why must pure oxygen never be used to ventilate or 'sweeten' a confined space before welding?

Answer: Oxygen enrichment makes clothing and materials ignite and burn violently

Oxygen-enriched atmospheres (above 23.5%) make ordinary materials, including clothing, extremely flammable.

Per AWS D1.1, final visual inspection of welds on ASTM A514 and A517 steels must be performed no sooner than how long after welding is completed?

Answer: 48 hours

The 48-hour delay allows delayed hydrogen-induced cracking to appear before acceptance.

Under AWS D1.1, E70XX low-hydrogen electrodes removed from hermetically sealed containers may be exposed to the atmosphere for a maximum of how long?

Answer: 4 hours

D1.1 limits E70XX exposure to 4 hours before the electrodes must be returned to a holding oven or rebaked.

In an inspection and test plan, what does a 'hold point' require?

Answer: Work cannot proceed until the designated inspection is performed and released

A hold point is a mandatory stop where work stays on hold until the specified party inspects and releases it.

Where should the welding work lead be connected to reduce safety and equipment hazards?

Answer: As close to the weld area as practical on the workpiece

A close work connection keeps stray welding current from flowing through chains, bearings, conduit, or structural members.

What is the primary purpose of an image quality indicator (IQI or penetrameter) in radiographic testing?

Answer: To verify the radiograph's sensitivity and technique quality

The IQI shows whether the radiographic technique is sensitive enough to reveal discontinuities of the required size.

Which control is generally most effective at keeping welding fumes out of the welder's breathing zone?

Answer: Local exhaust ventilation positioned near the arc

Local exhaust captures fumes at the source, which is preferred over dilution ventilation or PPE in the hierarchy of controls.

Long-term overexposure to which welding fume constituent is linked to a Parkinson-like neurological disorder?

Answer: Manganese

Manganese overexposure can cause manganism, a neurological disorder resembling Parkinson's disease.

A welder develops flu-like chills and fever several hours after welding galvanized steel; what is the most likely cause?

Answer: Metal fume fever from zinc oxide

Inhaling zinc oxide fumes from galvanized coatings causes metal fume fever.

Why must chlorinated hydrocarbon degreasing solvents be kept away from arc welding operations?

Answer: Arc UV radiation can break them down into toxic phosgene gas

Ultraviolet radiation from the arc decomposes chlorinated solvent vapors into phosgene, a highly toxic gas.

Per AWS D1.1 for statically loaded nontubular connections, what is the maximum undercut allowed on material 1 in. thick or greater?

Answer: 1/16 in.

For material 1 in. or thicker, undercut must not exceed 1/16 in. for any length.

When a nonconforming weld is proposed for a 'use-as-is' disposition, who must normally approve it?

Answer: The responsible Engineer

Accepting a nonconformance without repair is a design decision that requires the Engineer's approval and documentation.