CR Asia Singapore (CRAS) used a Common Header Delivery System to mechanically clean three common header heaters at ExxonMobil’s Pulau Ayer Chawan (PAC) refinery.
Most of these heaters are not piggable because of their design, as the pipes are inaccessible. Mechanical pigging requires a closed loop system so that bi-directional cleaning can be achieved. However, by using a Common Header Delivery System, the three common headers could be accessed and decoked without having to cut any pipes or remove the flanges
All ten passes on the three different sized heaters were decoked safely and on schedule. It was a notable achievement for CRAS as it was the first time the team had encountered a ten-pass configuration.