Vident Partners provides vetted welding expert witnesses for cases involving weld failures, welder qualification and inspection, hot work fires and explosions, welding fume exposure, and code compliance on structures, pipelines, pressure equipment, and vehicles nationwide. Request a referral today.
Find a Welding Expert →Overview
A welding expert answers one of two questions. Did this weld fail because of how it was made, or did welding work start the fire or expose the worker? The first is a question about metal, procedure and inspection. The second is about controls around hot work. A good expert works from the fracture, the procedure qualification, the inspection records and the code that applied. This page covers welds and welding practice. Why a metal broke in general belongs to a metallurgist or failure analyst, and fume-related illness belongs to an occupational physician.
The best known example is the 2010 San Bruno pipeline rupture. The NTSB found that the rupture was caused by a fracture that originated in the partially welded longitudinal seam of a short pipe section 1. The Board determined that the probable cause included inadequate quality assurance and quality control in 1956, which allowed the installation of a substandard and poorly welded pipe section with a visible seam weld flaw that grew over time to a critical size 1. It noted that the fabrication would not have met generally accepted industry quality control and welding standards then in effect 1. Two lessons recur in weld cases. A flaw may sit for decades before it fails, and the standard is the one in force when the work was done.
The analysis usually moves through these steps:
Pipelines show how specific those rules can be. Under 49 CFR 192.227, each welder or welding operator must be qualified under listed sections of API Std 1104 or section IX of the ASME Boiler and Pressure Vessel Code, with stated exceptions 2. Under 49 CFR 192.241, visual inspection of welding must be conducted by an individual qualified by appropriate training and experience, to ensure the welding followed the procedure and the weld is acceptable 3. Structures, vessels, ships and vehicles each have their own codes, and the contract often names one.
Many welding claims are about the sparks. OSHA's general industry rule says management must recognize its responsibility for the safe usage of cutting and welding equipment on its property and establish procedures 4. Before cutting or welding is permitted, the area must be inspected by the person responsible for authorizing the work, preferably with a written permit 4. Fire watchers are required where other than a minor fire might develop, or where listed conditions exist, such as appreciable combustible material closer than 35 feet to the point of operation 4. A fire watch must be maintained for at least a half hour after the work ends 4.
Work is not permitted in listed situations, including areas not authorized by management, sprinklered buildings while protection is impaired, and explosive atmospheres that may develop inside uncleaned or improperly prepared tanks 4. Construction has its own rule: drums and other containers that held flammable liquids must be handled under stated precautions 5. So a fire investigator and a welding expert often work together. One addresses origin and cause, and the other addresses whether the job met hot work practice.
Exposure claims look at the process, the metal, the ventilation and the duration. In construction, general ventilation must maintain welding fumes and smoke within safe limits, and local exhaust hoods must be placed as close as practicable to the work 6. For hexavalent chromium, one of the metal hazards an exposure case may involve, OSHA sets a permissible exposure limit of 5 micrograms per cubic meter, with an action level of 2.5 7. IARC's Volume 118, published in 2018, addresses welding 8. An industrial hygienist usually measures or reconstructs the exposure, and a physician addresses causation.
Look for a certified welding inspector, a welding engineer, or a metallurgist with hands-on experience with the code at issue. Ask about direct work on the process in dispute, since pipeline, structural and pressure vessel practice differ. A failure analyst addresses the fracture. A fire investigator addresses origin and cause. A safety engineer addresses hot work programs, and a structural or mechanical engineer addresses how the failed weld affected the wider system.
OSHA's general industry rule requires fire watchers where appreciable combustible material sits closer than 35 feet to the point of operation, and a fire watch must be maintained for at least a half hour after the work ends.
Case Types
Structural weld failures in buildings, bridges, and cranes
Pipeline and pressure vessel weld failures
Hot work fires and tank explosions
Welder qualification and inspection record disputes
Welding defects in vehicles, trailers, and equipment
Welding fume and hexavalent chromium exposure claims
Arc flash, electrocution, and burn injuries
Construction contract disputes over defective welding
Qualifications
Related Specialties
FAQ
Look for a certified welding inspector, welding engineer, or metallurgist with hands-on experience in the process and code at issue. Pipeline, structural, and pressure vessel practice differ. Ask whether the expert can direct lab work on the failed weld and read procedure qualification records.
An expert identifies the governing code, then checks the procedure, the welder's qualification, and inspection records, and examines the actual weld by fractography and metallography. The NTSB's San Bruno report shows how a weld flaw can sit for decades and then grow to a critical size.
Under 29 CFR 1910.252, fire watchers are required where other than a minor fire might develop or where listed conditions exist, such as appreciable combustible material closer than 35 feet to the point of operation. The watch must be maintained for at least a half hour after the work ends.
Under 29 CFR 1910.1026, the permissible exposure limit in general industry is 5 micrograms per cubic meter, with an action level of 2.5. An industrial hygienist usually measures or reconstructs exposure.
Usually the one in force, or named by contract, when the work was done. In San Bruno, the NTSB said the 1956 fabrication would not have met industry quality control and welding standards then in effect. An expert should identify which edition applied before saying a weld was deficient.
In general, welding expert fees are determined by the expert themselves, based on a variety of criteria. Among those criteria are hands-on experience, inspection credentials, forensic experience, laboratory needs, and publications. Vident does have some influence over expert fees by comparing experts within a specialty, but ultimately it is a personal decision by the expert.
Sources
Vident Partners connects attorneys with qualified welding expert witnesses. Complimentary consultation, 24-hour turnaround, no obligation.
Request an Expert →