Welding and cutting in boilermaker work

In April, two weeks before its planned spring outage, Riverbend Generating Station's Unit 2 trips on a waterwall tube leak. The operators see the drum level falling faster than the feedwater can make up, hear the hiss of steam from the furnace, and take the unit off line. Within a day, Ironbridge Industrial has a crew on site and the outage has been pulled forward. Kiera Lafontaine, now a second-year apprentice, is on that crew. Over the last year she has learned the safety side of the trade, heavy rigging and layout and fitting. This course follows her through a season in which cutting and welding are the work: the waterwall repair at Riverbend, a shell repair on Tank 14 at Bayou Junction, back-gouging on Northgate's spring work, and the floor tube welds in the Pinecrest Paper recovery boiler.

Welding and cutting run through nearly everything a boilermaker does. Before a tube can be replaced, it has to be cut out. Before a shell plate can be welded, its edges have to be cut and beveled. Before a cracked weld can be repaired, it has to be gouged or ground out to sound metal. Most of the welds boilermakers make are on pressure parts: tubes, headers, drums, shells and nozzles that will hold steam, water or process fluid under pressure. Those welds are covered by codes, made to written procedures by qualified welders, and inspected before the equipment goes back into service. The welder program teaches the processes in depth. This course is about using them on the work boilermakers do, in the places boilermakers work.

The processes a boilermaker uses

A boilermaker crew on an outage or a turnaround carries a small set of cutting and welding processes and uses each one where it fits.

Two things set boilermaker welding apart from shop welding. The first is position and access. A shop welder turns the work so that the weld is flat or horizontal; a boilermaker welds the tube where it is, often overhead or in a fixed position, sometimes with a mirror, inside a furnace on a scaffold, with the next tube 1/2 in away. The second is that the weld is going back into service on equipment that is already running. A repaired waterwall tube will see the full drum pressure and the full heat of the furnace within days of the last pass, so the weld has to be right the first time, and everyone involved, from the welder to the inspector, knows it.

Pressure welding is regulated work

Welding on boilers and pressure vessels is controlled by law in both countries. In the United States, each state that regulates boilers adopts the ASME Boiler and Pressure Vessel Code for new construction and the National Board Inspection Code, the NBIC, for repairs and alterations. Louisiana's boiler rules require that repairs and alterations follow the NBIC and be made by an owner or user, or by an organization holding a National Board certificate of authorization for the R symbol stamp. Ironbridge holds an R certificate, which means its quality program has been reviewed and it works under the eye of an authorized inspector, usually employed by the plant's insurer. Welders are qualified under ASME Section IX by the company they weld for, and each qualification is recorded on a welder performance qualification record, the WPQ.

The documents behind a code weld have names that every boilermaker learns early.

• Welding procedure specification (WPS). The written recipe for a weld: process, base metal group, filler metal, thickness range, positions, preheat, interpass temperature, postweld heat treatment, current, voltage and travel speed ranges. The welder works to the WPS posted at the job.
• Procedure qualification record (PQR). The record of the test weld that proved the WPS makes a sound weld with the required properties. The PQR is why the WPS can be trusted.
• Welder performance qualification (WPQ). The record that a particular welder passed a test weld using a WPS. It sets what that welder may weld: process, position, thickness, diameter, backing and filler group.
• Continuity log. The record that each qualified welder has used each process on code work within the allowed time. Under ASME Section IX, a welder who goes six months without using a process loses that qualification and must requalify.

Kiera is not yet a qualified pressure welder. She will spend her second year doing everything around the weld: cutting out, fitting, preheating, cleaning, grinding, watching the welders and running non-pressure welds. She will practice tube welds in Ironbridge's training booth at Port Allen and take her first test later in her apprenticeship. On the Riverbend repair she works with Marcel Beaudry, Ironbridge's lead tube welder, who has been welding boiler tubes for twenty-two years and still keeps his own notebook of every repair.

Checking the welders before the outage

The first thing Harjit Gill, Ironbridge's quality control manager, does when the crew is called out is check that every welder on the list is current. A welder whose qualification has lapsed cannot strike an arc on a pressure part, however good they are, and finding that out after the weld is made means cutting the weld out. Harjit keeps the continuity log for every welder in a spreadsheet; before the crew leaves the yard, he runs the list against the date.

# Welder continuity check before the Riverbend outage (US units)
from datetime import date

today = date(2027, 4, 12)

def add_months(d, n):
    y, m = divmod(d.month - 1 + n, 12)
    y, m = d.year + y, m + 1
    days = [31, 29 if y % 4 == 0 else 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][m - 1]
    return date(y, m, min(d.day, days))

# (welder, process, date the process was last used on code work)
log = [
    ("M. Beaudry", "GTAW", date(2027, 2, 20)),
    ("M. Beaudry", "SMAW", date(2026, 11, 2)),
    ("S. Nakamura", "GTAW", date(2026, 9, 30)),
    ("S. Nakamura", "SMAW", date(2027, 3, 15)),
    ("J. Okeke", "SMAW", date(2027, 1, 10)),
    ("J. Okeke", "FCAW", date(2026, 12, 1)),
    ("R. Haldane", "GTAW", date(2026, 10, 20)),
]

print("WPQ continuity, checked", today.isoformat())
for who, proc, last in log:
    lapse = add_months(last, 6)          # qualification lapses 6 months after last use
    left = (lapse - today).days
    if left < 0:
        status = "LAPSED - requalify before welding"
    elif left <= 30:
        status = f"OK, but lapses in {left} days"
    else:
        status = "OK"
    print(f"{who:12} {proc:5} last used {last.isoformat()}  lapses {lapse.isoformat()}  {status}")

WPQ continuity, checked 2027-04-12
M. Beaudry   GTAW  last used 2027-02-20  lapses 2027-08-20  OK
M. Beaudry   SMAW  last used 2026-11-02  lapses 2027-05-02  OK, but lapses in 20 days
S. Nakamura  GTAW  last used 2026-09-30  lapses 2027-03-30  LAPSED - requalify before welding
S. Nakamura  SMAW  last used 2027-03-15  lapses 2027-09-15  OK
J. Okeke     SMAW  last used 2027-01-10  lapses 2027-07-10  OK
J. Okeke     FCAW  last used 2026-12-01  lapses 2027-06-01  OK
R. Haldane   GTAW  last used 2026-10-20  lapses 2027-04-20  OK, but lapses in 8 days

The check shows three things. Most of the crew are current. Marcel's SMAW qualification and R. Haldane's GTAW qualification will lapse during the outage unless they use the processes on code work before the dates shown, which they will on the first day. S. Nakamura has not used GTAW on code work for more than six months, so Harjit takes her off the GTAW root list and books her a requalification test in the training booth; she can run SMAW fill and cap passes in the meantime, because that qualification is current. Harjit's rule is to review the log every Monday during a job and the day before every call-out.

Shop work and field work

Ironbridge's yard has a fabrication shop, and some of the welding for the Riverbend repair happens there: the new two-tube panel section is cut, beveled, fitted and welded on a bench, where the welder can position the work and the shop's inspector can check it before it leaves. The field welds, where the new section joins the old wall, happen in the furnace. Field welding brings its own problems: wind and draft, cold steel, poor light, awkward access, dirty and wet surroundings, and a schedule that is costing the plant money every hour. A good field crew controls what it can. It builds a habitat or windbreak, warms the steel to the preheat on the WPS, lights the work, keeps electrodes in a heated oven at the job, and stages its tools so the welder spends the shift welding rather than looking for a grinder.

Cutting is shared between shop and field in the same way. A shell plate for Tank 14 is cut and beveled on the shop's burning table; the opening it fills is cut in the field with a track-mounted torch. Tubes are cut in the field with saws and clamshell cutters, never with a torch inside a boiler, because slag in a tube can block it, and a blocked tube in a furnace overheats and fails.

Hold points and the people who inspect

Every pressure repair is planned around hold points, steps at which the work stops until someone has checked it. On the Riverbend waterwall, the repair plan names five: the cut-out and end preparation, the fit-up of each joint, the completed root pass on the first joint, the radiographs of every butt weld, and the hydrostatic test. At each one, Harjit checks the work for Ironbridge, Peg Lindqvist checks it for Riverbend as the owner's inspector, and Grant Mahler, the authorized inspector, is notified for the points he has asked to witness. Annika Sorensen, a radiographer and ultrasonic technician from Keystone Inspection, takes and reads the radiographs.

Hold points can feel like delays, but they save time. A fit-up rejected at the hold point costs a few minutes with a grinder; the same fault found on a radiograph costs a cut-out and a rewelded joint, and found in service it costs another outage. Kiera's job at every hold point is to have the work ready, clean and measured, with the readings on the traveler, the sheet that follows the joint through the repair.

Safety in cutting and welding on plant work

Every cutting and welding job on a plant site happens under a hot work permit, inside the permit system that BLR-110 covered. In a boiler, the hazards stack up: confined space entry, work at heights on a scaffold inside the furnace, fumes from coated electrodes and from paint and deposits on old tubes, ultraviolet and infrared light, electrical hazards from welding leads running in a wet, steel enclosure, compressed gas cylinders that must stay outside the boiler, and fire in the insulation and lagging on the casing side. The welding crew and the fire watch work together; the fire watch stays after the last arc for the time the permit sets, checking the casing side, where smoldering insulation can hide.

The welding lead itself deserves respect in a boiler. A boiler is a large, grounded steel box, and a welder standing on it is part of the circuit. Leads are inspected for cuts before every shift, the work return clamp goes on the work as close to the weld as possible rather than on the scaffold, and the welder keeps dry gloves and a dry insulating mat. Electrode holders are never left on the scaffold boards with an electrode in them.