VALVES MAKE THE DIFFERENCE IN
DELAYED COKING
mproving safety, maximizing
Ithroughput and profitability, and
minimizing long-term maintenance
and indirect operating costs are difficult tasks for refineries today.
Through innovative design, valves
are put into processes where traditionally they have never been used
before; a good example is coke drum
unheading valves. Also proving successful are design efforts to address
specific operational challenges of
older valve technologies, such as the
improvements that have been made
in isolation valve technology. These
successful efforts have resulted in
refinery valves that are safer, faster
and more reliable than ever before.
TRADITIONAL MANUAL METHODS OF
COKE DRUM UNHEADING ARE LABOR
INTENSIVE, COSTLY TO MAINTAIN,
EXPENSIVE TO REPAIR AND CARRY
INHERENT RISK FOR PERSONNEL ON THE
UNHEADING DECK. THE DEVELOPMENT
OF THE COKE DRUM BOTTOM UNHEADING
VALVE WAS A FIRST STEP IN WHAT HAS
BECOME A NEW STANDARD IN SAFETY
AND RELIABILITY IN COKE DRUM
UNHEADING. BY DAVID ANDERSON
SAFETY OF PLANT
PERSONNEL AND
EQUIPMENT
The process of coke drum unheading
(or opening) within oil refining has
traditionally been one of the most
dangerous activities in the industry.
Such operations have resulted in
many accidents and some fatalities
over the years. In a joint bulletin
entitled, Hazards of Delayed Coker
Unit (DCU) Operations, released in
WHAT IS
DELAYED COKING?
Delayed coking is a thermal-cracking
batch process that involves heating
residual crude oil (resid) in a high-temperature furnace to thermally
crack its hydrocarbon molecules,
converting the resid into valuable
liquids and gases. The process leaves
behind a carbon material—similar in
appearance to lava rock—called
petroleum coke, pet coke, or just
simply "coke." The cracking process
started in the furnace and is
"delayed" or completed in the furnace, thus the name delayed coking.
