- Products
- Severe Service Valves
- Anti-Surge - Compressor Recycle
- Pipeline Surge Relief Control
- Centrifugal Pump Minimum Flow Recirculation
- Fire Water Deluge System
- Separator Level Control
- Vector Velocity Control Trims
- Turbotrol and Multi-Spline Trims
- Choke Valves
- Globe Control Valves
- Aftermarket
- Rotary Control Valves
- Actuators and Instruments
- Subsea Products
- Product Enquiries
- Industry Sectors
SEVERE SERVICE
VALVES
SEVERE SERVICE
VALVES
PIPELINE SURGE RELIEF CONTROL
(incompressible fluids)
If a valve suddenly closes or a pump trips out, either at the start or the end of a pipeline or at an intermediary pump station, the flow at that point will be brought to rest or significantly reduced. The fluid upstream and downstream is not “aware” of this stoppage and continues to flow under its mass momentum. The fluid upstream is compressed, causing a pressure surge, while downstream there will be a rarefaction in pressure, which will encourage reverse flow.
Pressure surges and reverse flows are extremely dangerous, causing damage to pumps and possibly fracturing pipelines. A surge on a long pipeline operating at a normal pressure of 17.5 bar can generate a transient pressure of 96 bar if uncontrolled.
Example of severe service surge-control application
One customer was experiencing severe vibration due to cavitation with a competitor’s control valve. KKI was asked to supply a trial valve that would eliminate the cavitation and provide stable control while subjected to extremely high velocities. The valve also had to fit into the existing space on the pumping station.
Seven stages of pressure drop were specified by KKI to ensure that the pressure of the medium did not fall below the vapour pressure, thereby preventing cavitation and eliminating both the noise and vibration that had previously been experienced.
Great care was also taken to control the velocity through the valve. Although the valve was described as a 16” angle design, the trim components and size were the same as used on a 24” valve.
Prior to shipment to Alaska, the valve was fully tested by KKI for confirmation of both the CV and flow characteristic. After successful extensive customer trials, KKI received an initial order for 36 of these anti-surge pipeline control valves, each one specifically designed around the flow conditions of each individual pump. KKI subsequently received and delivered an order for ten more units. The valves continue to function satisfactorily with minimum service requirement.
