Furnace / Fired Heaters Tube decoking ON-LINE! at Distillate Synthesis Plant in Malaysia – World First!

Top view of heater Blocked furnace fired heater tube Coke deposit removed Header pipes to represent furthest distance Morning cleaning information Serpentine under construction Serpentine installed in furnace booth CCTV internal image Tube Tech bespoke pumps Furnace efficiency graph

Blocked serpentine furnace coils cleared in one day

The client asked Tube Tech to develop a technology and method  to clear a single fully blocked serpentine furnace tube measuring  100mm diameter x 45m.

Initially the client wanted to follow the traditional route of unblocking the furnace by cutting off the bends, unblocking the tube by using water jets and re-welding. However this meant switching off all 4 furnaces at a cost of many millions of dollars.

Tube Tech a globally renowned engineering solutions provider suggested unblocking both lines whilst the unit was online at 430 degrees centigrade so as to avoid incurring these costly production downtime for the plant.


As with many projects this would be another challenging first for Tube Tech. A replica furnace was constructed, directly linked to a heater at their UK headquarters. The tube was blocked with concrete to simulate harder than average fouling and the temperature raised to 430C on-line.

An independent, globally recognised petrochemical consultant witnessed the trial on behalf of the client and approved its use.


The trial was were carried out in three stages.

Heat eat was quenched by a constantly-monitored injection of water with steam being safely contained and vented.

The furnace tubes were navigated by means of a modified high-pressure jetting lance, modified to withstand the severe temperatures and high torque which it would encounter within the furnace tubes. Buoyancy pockets would assist the drill in reaching the “coal face.”

Mike and his team practiced the procedure many times with military precision at over 430 degrees C.

When on site the client had reduced the temperature to 120 degrees due to other site conditions. As a result the blockage was cleared in 1 day instead of the anticipated 3.

Tube Tech Comment

Mike Watson, Technical & Managing Director: “Whilst we were unable to carry out cleaning online at 430 degrees C we had proved the concept several times in front of an independent furnace specialist.

Still navigating 45m through bends to unblock rock solid coke formation at 120 degrees C is no easy task and may in itself be a world first. Of course furnace de-coke and cleaning online for the client would have been the icing on the cake. Nevertheless the client was ecstatic to hear we had broken through both blocked serpentine furnace coils so quickly, which was to substantially improve the furnaces performance.”

Contact Tube Tech Today

For more information or to discuss your cleaning challenge call us on +44 1268 786999 or e-mail info@tubetech.com, alternatively click here to fill out our contact form.

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