Vacuum Distillation Valves

You are here: Home » Valve Applications

Vacuum distillation is one of the oldest and most important refinery processes. Datian valve specialises in producing refinery valves that improve efficiency and deliver significant cost savings.

VACUUM DISTILLATION PROCESS

Vacuum distillation is the process of separating atmospheric residue to produce heavy, medium, and light gas oil as well as a vacuum residue. Approximately 50% of the VDU output is light or middle vacuum gas oil that are typically processed further in distillate hydrotreating units. They are relatvely unproblematic. Please see top left tab for VDU process steps.

Vacuum Residue Refinery Problems

Heavy gas oil or vacuum residue make up the rest. The vacuum residue is a thick slurry like medium with an API rating in the range of 5° to 7°. As a result, VDU pipelines and equipment can clog and capacity is severely reduced. This is illustrated in the picture below, which shows two ball valves (onr open and one closed) interconnected with a T-Piece. The dead space area is shown in black.

The answer to this problem in the past has been to continuously back flush the lines to remove sediment and slurry that has settled in dead spaces – typically in piping T-pieces or ball valves. However, continuous flushing adds cost and reduces VDU capacity by approximately 10%.

1) THE NO DEAD SPACE DIVERTER VALVE

The Datian valve VDU Diverter valve shown above eliminates the need for continuous back flushing. The associated dead space accumulating equipment (t-pieces and ball valves) are replaced by the Datian valve diverter valve. Because the diverter valve is dead space free, continuous flushing is no longer required. The piston (in green) on the left hand side closes the left leg and is flush with the inlet. The right hand piston is in the open position but seals flush with the outlet. There is no redundant space for sediment, slurry, or coke particles to settle. As such the Datian valve diverter valve can be seen as a seamless extension of the plant piping.

In addition the valve is more compact than the comparible t-piece and ball valves. Finally, it allows the medium to be routed into 2 or more process lines – one for example for intermediate storage and the second to a FCC or delayed coking unit.

ISOLATION AND EMERGENCY SHUT DOWN VALVES

As with the special VDU Diverter valve, Datian valve has worked with several refiners and engineering offices over the past few years to create a reliable emergency bottoms isolation system. This can include the above mentionned diverter valve or be achieved through a combination of:

2) DATIAN VALVE Y-GLOBE VALVE FOR ISOLATION (REFINERY VALVE DESIGN)

The Datian valve Y-Globe valve is ideal for distillation processes due to it's ability to handle large flow rates in an unimpeded manner. This is a result of it's:

Like the diverter valve, the Y-Globe eliminates dead space with the use of piston or back seating options. It can be provided with a quick opening or closing on/off trim. It is the ideal isolation valve for vacuum residue isolation applications.

3) EMERGENCY SHUT-DOWN CONTROL VALVE

In a fire related emergency in the CDU and VDU section of the refinery, the emergency shut-down control valve is critical. Datian valve has designed a special heavy duty control valve with on/off functionality that is:

All three of the valves profiled in this expose bring significant safety and efficiency benefits to the vacuum distillation unit.

TOP RATED PRODUCTS

VIDEO GALLERY

TECHNICAL ARTICLE

Pump Run Out Protection
Pump Run Out Protection
2014/09/16 - pm3:58
Applications of DATIAN ARC valve
2014/09/16 - pm3:43