CWS (CWNP) flashcards
CWS · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Arc flash filter shade
- The darkness rating of a welding helmet lens. Shade number rises with amperage and process; SMAW at 200 A typically needs shade 12, low-amp GTAW shade 8–10.
- Hot work permit
- A written authorization required before welding outside a designated area. It verifies fire hazards are controlled and specifies a fire watch that remains after work ends.
- Fire watch duration
- The period a trained watcher stays at the hot-work site after welding stops. Common rule is 30 minutes minimum, with a final check before leaving the area.
- Acetylene pressure limit
- Acetylene line pressure must not exceed 15 psi (103 kPa). Higher pressure risks decomposition and explosion, so regulators are set below this limit.
- Discontinuity vs defect
- A discontinuity is any interruption in weld uniformity. It becomes a defect only when it exceeds the acceptance criteria of the governing code.
- Hexavalent chromium fume
- A carcinogenic fume produced when welding stainless steel. Its exposure limit is extremely low, so local exhaust ventilation at the arc is required.
- Visual inspection scope
- Examination performed before, during, and after welding. It detects surface porosity, undercut, spatter, and crater cracks but cannot reveal internal lack of fusion.
- Undercut acceptance limit
- Under AWS D1.1 statically loaded butt joints, undercut shall not exceed 1/32 in (0.8 mm), with a maximum 1/16 in (1.6 mm) for intermittent undercut.
- Flashback arrestor
- A device fitted at the regulator and torch on oxy-fuel lines. It stops a flame from traveling back into the hose or cylinder.
- PPE baseline for welding
- Leather gauntlet gloves, flame-resistant sleeves or jacket, safety glasses under the helmet, and hearing protection where the noise survey exceeds 85 dBA.
- Deposition rate formula
- Pounds of filler deposited per hour. For E70 stick electrodes, a working approximation is DR = 0.0003 × current in amps × operating factor.
- Operating factor
- Arc-on time divided by total paid time. It captures fit-up, positioning, chipping, and breaks; raising it from 25% to 40% cuts labor cost per unit by about 37%.
- Heat input formula
- Heat input in kJ/in = (60 × volts × amps) ÷ (1000 × travel speed in in/min). Higher travel speed lowers heat input and reduces distortion.
- Cost per foot of weld
- Sum of filler metal cost (deposited weight per foot × price per pound ÷ deposition efficiency) and labor cost (labor rate ÷ travel speed in ft/hr).
- Fillet weld over-welding
- Deposited area scales with leg size squared. A 1/4 in fillet where 3/16 in is required adds about 78% more metal, raising cost with no strength benefit.
- Deposition productivity metric
- Pounds of deposited weld metal per labor hour, tracked against a target set by process, position, and joint type. A falling trend signals fit-up or cleanup problems.
- Rework cost impact
- Rework and scrap are the largest hidden cost drivers. A 2% rework rate on a job with 20% margin can erase profitability, so defects must be tracked by type.
- Positioner productivity gain
- Converting a vertical-up weld to flat with a positioner typically raises deposition rate 30–50% and improves operating factor, so labor standards must be re-baselined.
- Process deposition comparison
- FCAW and GMAW deposit metal two to four times faster than SMAW. Process substitution is often the largest single productivity lever in a weld shop.
- Travel speed effect
- Raising travel speed lowers heat input and distortion but risks lack of fusion if the puddle does not wet in. It must stay within the qualified WPS range.
- WPS and PQR relationship
- A WPS is the written procedure; the PQR is the test record that supports it. The supervisor verifies welders follow the qualified WPS parameters without altering them.
- Qualification vs certification
- Qualification is demonstrated by a performance test. Certification is the employer's written confirmation that the welder is qualified; the employer owns and signs it.
- Continuous qualification lapse
- A welder's qualification expires after a defined period without welding with the qualified process, commonly 6 months under ASME. Supervisors must log arc time to prevent lapses.
- Progressive discipline sequence
- Verbal coaching, then written warning, then final warning, then termination. Each step is documented with dates and specific observed behavior to withstand challenge.
- Corrective action model
- Contain the defect, find the root cause with 5 Whys or a fishbone, implement the fix, verify effectiveness, and update the WPS or work instruction.
- Root cause vs blame
- Blaming the welder is not a corrective action. A valid root cause addresses the system, such as unclear instructions, poor fit-up, or unqualified parameters.
- Shift handoff documentation
- Open nonconformances, in-process WPS parameters, and equipment issues must be passed in writing. Verbal-only handoffs are a common source of repeated defects.
- Training gap analysis
- Comparing required skills against the welder's qualified range. Gaps in code-required parameters need requalification, not just technique coaching.
- Behavior-specific feedback
- Feedback that names the observed action, its impact, and the expected correction, such as travel speed exceeding the WPS range on the last three passes.
- Safety enforcement consistency
- Supervisors must enforce PPE and hot-work permits uniformly. Inconsistent enforcement is a leading indicator of incident risk and erodes safety program credibility.
- Welder performance test
- A test weld made under controlled conditions to demonstrate a welder can produce sound welds per the applicable code, recorded and certified by the employer.
- Documented coaching record
- A dated note of the observed behavior, the discussion held, and the agreed correction. It supports later discipline and demonstrates supervisory due diligence.