Letting off Steam: Steam traps reduce failure and condensate return at refinery
Written by Sam Mawby
Keeping
on top of the constant challenge of repairing and replacing thousands
of mechanical steam traps is no longer a problem at KNPC’s Shuaiba
Refinery in Kuwait following the successful conversion of 1,750
mechanical traps to Ottawa-based Thermal Energy International Inc.’s
award-winning GEM Venturi orifice steam-trap design. As a result, KNPC,
a subsidiary of the Kuwait Petroleum Association, has seen the
high-pressure (HP) hot condensate header pressure drop from highs of
175 psig (pound-force per square inch gauge) to just 90 psig.
Commissioned in 1968, Shuaiba Refinery, located some 33 miles south of
Kuwait City, occupies nearly 330,000 acres, producing about 30 types of
light, medium and heavy petroleum products. These consist of mainly
gas, ordinary naphtha, various kinds of fuels such as high-octane
gasoline, kerosene and ATK as well as automotive diesel, marine diesel,
fuel oil and sulphur.
As is the case in oil refineries worldwide, steam is the primary means
of transporting energy from the numerous boilers and steam generators
to the point of use and is used throughout the oil refinery for
applications ranging from trace heating systems designed to keep the
product at the correct viscosity to large reboilers consuming many tons
of steam per hour.
As the steam gives up its useful heat, it condenses to water. The steam
trap’s function is to remove this water and air from the steam
pipe-work. At Shuaiba Refinery, the mechanical steam traps were failing
at a rate of in excess of 10 percent per annum. Steam traps can fail in
either the open position, resulting in the trap passing live steam, or
closed, which prevents the discharge of condensate from the system.
When Canada’s was first approached by the Shuaiba Refinery, failed
mechanical traps had caused the condensate return pressure to rise to
175 psig, preventing the 150 psig steam stem from being able to
discharge. During a recent unplanned boiler outage, the refinery was
able to run on just two boilers, which prior to the installation of the
GEM Venturi Orifice steam traps would have resulted in a loss of steam
pressure to the refinery’s extremities and impacted on production.
“Use of GEM traps has resulted in an 85 psig reduction in the HP hot
condensate header pressure as well as steam savings from the reduction
in steam loss,” said Habib Atesh, engineering and maintenance manager
at Shuaiba Refinery. “In addition, GEM traps are superior as only the
strainers require maintenance.”
Instead of utilizing a valve mechanism to close off steam for maximum
energy and water conservation, the efficient GEM steam traps use the
Venturi orifice design to drain condensate from the steam system. As
the GEM steam traps have no moving parts to wedge open or fail, “it
provides the ultimate in reliability necessitating only minimal
maintenance and requiring no spares, testing or monitoring equipment,”
the company says.
Available in a range of sizes for a full cross section of applications,
the hardwearing GEM steam traps are manufactured from corrosion
resistant stainless steel and are guaranteed for 10 years, eliminating
the need for repair or replacement. They can provide a fast payback
from reduced energy costs and increased reliability. In addition it can
improve product processing by enhancing process control of the cleaning
system, and also reducing equipment repairs, downtime and replacement
costs.
Sam Mawby is technical director with Thermal Energy International Inc. in Ottawa. For more information, visit www.thermalenergy.com. This was originally published in REM.
Keeping
on top of the constant challenge of repairing and replacing thousands
of mechanical steam traps is no longer a problem at KNPC’s Shuaiba
Refinery in Kuwait following the successful conversion of 1,750
mechanical traps to Ottawa-based 
