Cleaning and Inspection Challenges No.7
Author: Mike Watson, Managing Director, Tube Tech
Following a recent survey of refinery operators from across the world Tube Tech have compiled the Top 10 cleaning and inspection challenges faced by the refining industry.
As a world leading specialist industrial cleaning contractor Tube Tech have solved some of the refining and petrochemical sectors most difficult cleaning challenges. Tube Tech asked over 2500 refinery operators to complete their survey and the Top 10 cleaning and inspection challenges were developed as result of the survey feedback.
Below is the 7th most common cleaning and inspection challenge faced by the refining sector.
No 7 On-Line / Live Flare Line Cleaning.
Flare lines are crucial within the refining and petrochemical industries to deliver and burn hydrocarbon gases that cannot be recovered or recycled. Instead of excess gases being released into the atmosphere burning them within flare systems is far more environmentally acceptable. During flaring the excess hydrocarbon gases are mixed with steam and/or air to create water vapour and carbon dioxide. Refining and petrochemical industries try to minimise the use of flares and many restrict their use to during start-up and shutdown and during unplanned power interruptions.
The flare line system comprises a complex of pipework which passes through the refinery. Much of this pipework is suspended on gantries about 4.6 m above ground.
- Safety – Risk of fire due to pyrophoric iron sulphide, hydrocarbon condensates and gases in the line. Due to the presence of explosive chemical components such as carbon monoxide and hydrogen sulphide within the flare line, no oxygen is allowed to enter the system and no gasses are allowed to escape during cleaning.
- Access – Flare lines are often supported approximately 6m off the ground and can sometimes support other pipelines below them. This means that traditional water pigging is not an option as lines cannot support the extra weight of the water.
- Inspection – Due to limited access-ability, deposit characteristics and dimensions of flare lines, it can often be difficult for clients to assess integrity.
- Financial – Taking a flare line off-line for cleaning means that anything feeding into the line must shut down, which means the entire refinery / petrochemical plant – often costing a substantial 7 figure sum per day.
- Tube Tech’s research and development department have developed a unique technology to clean flare lines without shutting down i.e. on-line even whilst flaring, providing clients with the opportunity to clean flare lines at their own convenience.
- Tube Tech’s method copes with temperatures and pressures inside the flare line, preventing ingress of oxygen, the escape of toxic gases and subsequent flash point. Cleaning is carried out using bespoke pressure lances designed to be heat and scratch resistant when fed into small 25mm vent and drain valve entry points on the flare line.
- An alternative technology is the DrifTT system using a special pig that is driven through the flare line by the motive expansion of nitrogen. As an inert substance, nitrogen does not pose any risks when it makes contact with the pyrophoric deposits within the line.
- Once the DrifTT system had passed through the line a foam swab is sent down the line to clear out the loosened debris.
- Tube Tech also uses intrinsically-safe inspection equipment to take digital images before and after cleaning.
- Tube Tech maintains a considerable digital video archive on flare line cleaning means we can demonstrate our ability to clean flare lines in situ and on-line anywhere in the world.
Tube Tech encourages out of the box thinking engineers to call us to develop more innovative methods to clean static heat transfer and process equipment faster, safer, cleaner, in-situ and online.
Tube Tech are the only company to provide a comprehensive close out report after a cleaning and inspection project has been completed. The report is a storyboard from start to finish which includes contacts, conversations, technical, commercial and future cleaning and inspection recommendations.
Operators interested in the cleaning of any asset including flare lines will initially be asked to provide the following information:
- Technical drawings including any and all access points however large or small,
- Digital images of the working area including any access points,
- Images or better still video clips with sound of the deposit being chipped or scraped away using a fingernail, screwdriver or hammer for example;
- Where appropriate, a tube or pipe sample with attached deposit is extremely helpful (to be sent by DHL).
Once received, Tube Tech provide a completed project summary questionnaire to approve. A technical and commercial proposal is then provided to include a variety of technology options. If required a site visit can be arranged anywhere in the world. With such attention to detail Tube Tech can hit the ground running, provide hourly reporting and digital archives culminating in a global service second to none.