Skip to content

Cutting torch hose separates from flame arrestor

An incident has come to IMCA’s attention in which an Oxy-Acetylene cutting torch hose separated from the flame arrestor, resulting in a flashback. The incident occurred during welding modification of stabbing guides inside a pile driving hammer. While cutting a steel plate with a torch, the pipefitter experienced a flashback of flames as the connection of the hose suddenly came loose. Immediately the fire watch used the standby fire extinguisher and put out the flames. The men stopped the job and called for the supervisor. The pipefitter was unharmed and no property damage occurred.

Investigation revealed the following:

  • Immediate cause: was identified as inadequate repair using unsuitable techniques and methods. The inside diameter of the hose was larger than the one suited for this type/size of nipple so tape was used to make up the difference. The clamp could not tighten against the barb on the nipple and when the tape warmed up the hose and clamp slipped off over the barbed end;
  • Root Cause: was use of miss-matched materials that were inadequate for the task. The correct size hoses with clamps were ordered but were unavailable at the time. An improvised repair was made using tape to secure a tight fit.

The following corrective actions were taken:

  • Inspect all torch hoses and remove all with this type of improvised connection;
  • Crew trained and provided awareness in proper materials and procedure;
  • A ‘safety stand down’ was conducted on-board to reiterate the importance of pre-job inspection and carrying out the job using the safest methods and materials.

Safety incidents involving pressurised gas fittings, Oxy-acetylene cutting equipment and gas cutting in general are quite commonplace. A sample is included here – please refer to the following similar incidents (key words: flame arrestor, flashback, incorrect, acetylene), but there may be others.

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of all. The effectiveness of the IMCA Safety Flash system depends on Members sharing information and so avoiding repeat incidents. Please consider adding [email protected] to your internal distribution list for safety alerts or manually submitting information on incidents you consider may be relevant. All information is anonymised or sanitised, as appropriate.

IMCA’s store terms and conditions ( apply to all downloads from IMCA’s website, including this document.

IMCA makes every effort to ensure the accuracy and reliability of the data contained in the documents it publishes, but IMCA shall not be liable for any guidance and/or recommendation and/or statement herein contained. The information contained in this document does not fulfil or replace any individual’s or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.