Safety & Compliance · SOP

Welding Fume Extractor Filter Replacement & Airflow Check

This procedure details the safe replacement of the main filter element and subsequent airflow verification on a stationary welding fume extractor. Routine execution maintains capture velocity at the extraction nozzle and prevents motor overload.

Estimated Time

30 min

Difficulty

Intermediate

Regulation

WorkSafeBC OHS Reg.

Version

1.0

Free download — no sign‑up, no email.Take this SOP to your shop floor and make it yours.

↓ PDF (print‑ready) ↓ Word (editable)

Purpose

To establish a repeatable, safe method for replacing the primary filter element (HEPA/carbon) on a welding fume extractor and verifying that the system’s capture airflow meets minimum operational thresholds. Proper filter replacement prevents fugitive emissions, keeps the motor from running under excessive static pressure, and ensures compliance with regional occupational health & safety ventilation standards.

Scope

This SOP applies to all stationary welding fume extractors equipped with a removable filter cassette (HEPA, activated carbon, or combination) and an integral fan assembly. It covers the filter cartridge change-out, cleaning of internal housing, and a quantitative airflow check using an anemometer. Does not include ductwork inspection or replacement of fan/motor components.

Safety Precautions

LOTOLockout/Tagout: Isolate and lock out the main electrical disconnect for the fume extractor. Verify zero energy with a qualified electrician before opening any access panels.
PPEPersonal Protective Equipment: Wear safety glasses, impact-resistant gloves, and welding-rated gauntlets. If the spent filter contains hazardous particulates (e.g., hexavalent chromium), use a half‑face respirator with P100 filters.
CONTContaminated Filter Handling: Place the used filter directly into a sealed plastic bag to prevent dust resuspension. Dispose per local hazardous waste regulations.
BURNHot Surfaces: If the extractor was recently operated, allow 15 minutes cool-down before opening. Use a thermal imager or touch-check with the back of the hand first.

Required Tools & Materials

Replacement filter cartridge (HEPA/activated carbon — OEM part number)
Screwdriver set (flathead & Phillips No. 2)
Adjustable wrench or socket set
Digital anemometer (hot‑wire or vane, ±0.1 m/s resolution)
Compressed air blow‑gun (for cleaning housing interior)
Disposable rags, mild degreaser
Lockout/tagout kit (padlock, hasp, danger tag)
Torque wrench (if fasteners have specified torque)
Safety glasses, welding gauntlets, P100 respirator (if required)
Sealed waste bag for used filter

Digitize Your Safety & Compliance

Throw away the paper checklists. Have your operators complete safety audits, crash reports, and daily inspections directly on their phones using SafeDesk. Stay compliant with WorkSafeBC without the administrative bloat.

Try SafeDesk →

Procedure: Step-by-Step

1Lock out / tag out (LOTO). Turn off the extractor at the main disconnect. Apply a padlock and danger tag. Test the start button — the unit must not energise. Notify affected personnel.

2Access the filter housing. Remove the side access panel using a Phillips screwdriver. Store fasteners in a labelled container. If a secondary inner door is present, release the over‑centre latches.

3Remove the spent filter. Grasp the filter handle (or carefully pry the frame) and slide it straight out. Avoid tilting. Place the used filter directly into a sealed waste bag. Dispose according to facility hazardous waste protocol.

4Inspect and clean the housing. Use a damp rag to wipe away accumulated dust and debris. Do not use compressed air inside the housing — it will redistribute fine particulates. Check gasket surfaces for tears or compression set. Replace gasket if damaged.

5Install the new filter. Orient the new filter so the airflow direction arrows point toward the motor/fan. Slide it fully into the track until the gasket contacts the housing flange. Push evenly to ensure full seal.

6Reassemble and torque. Replace the access panel and tighten fasteners in a cross‑pattern sequence to 5 N·m (or per manufacturer spec). Re‑energise following LOTO removal procedure.

7Measure capture airflow. Start the extractor and let it stabilise for 30 seconds. Hold the anemometer probe at the centre of the extraction nozzle face, 25 mm from the opening. Record the velocity (m/s). Acceptable threshold: ≥ 0.5 m/s. If below spec, inspect for duct blockages or fan issues.

8Document and sign off. Enter the date, new filter part number, measured airflow, and any observations into the maintenance log. Attach a “Filter Changed” sticker with date to the housing. Notify shift supervisor that the unit is back in service.

Welding Fume Extractor Filter Replacement & Airflow Check

Digitize Your Safety & Compliance

Software that works like your best tools.