Process Description
Liquid Pipeline Overview
Supplier No. 1 is located at the west end of the West Leg of the pipeline. Supplier No. 1 normally supplies 20 MBPD of gasoline to the Liquid Pipeline. The west end of the pipeline normally operates at 430 PSIG.
Pump Station No. 1 handles all the flow of liquid coming from Supplier No. 1 via the West Leg. Pump Station No. 1 consists of two centrifugal Booster Pumps P-101A/B which are configured in series operation. Normally only one of the pumps is in operation. The inlet pressure to Pump Station No. 1 is normally 350 PSIG. The outlet pressure of Pump Station No. 1 is normally 555 PSIG.
The liquid from Pump Station No. 1 enters the western end of the Central Leg. Supplier No. 2 is connected into the Central Leg approximately midway along the pipeline leg. Supplier No. 2 normally supplies 15 MBPD of gasoline to the Liquid Pipeline. The combined flow from suppliers No. 1 and 2 are sent to Pump Station No. 2 at the east end of the Central Leg.
Pump Station No. 2 consists of two centrifugal Booster Pumps P-201A/B which are configured in series operation. Normally only one of the pumps is in operation. The inlet pressure to Pump Station No. 2 is normally 360 PSIG. The outlet pressure of Pump Station No. 2 is normally 554 PSIG.
The liquid from Pump Station No. 2 enters the western end of the East Leg. Supplier No. 3 is connected into the East Leg approximately midway along the pipeline leg. Supplier No. 3 normally supplies 15 MBPD of gasoline to the Liquid Pipeline. The combined flow from suppliers No. 1, 2 and 3 (50 MBPD) are sent to the Terminus at the east end of the East Leg. After being metered at the Terminus, the fuels are sent to a tank farm at battery limits. The Terminus normally operates at 100 PSIG.
Storage Tank T-701 is connected to the East Leg of the pipeline just before the Terminus. In case the liquid fuels cannot be taken off to the tank farm after the Terminus, the fuels can be sent to Storage Tank T-701 so that the flow rates from Suppliers No. 1, 2 and 3 do not have to be reduced. Return Pumps P-701A/B are used to return fuels from T-701 back to the East Leg as needed.
Supplier No. 1
Supplier No. 1 supplies hydrocarbon fuel (normally gasoline) to the West Leg of the pipeline. The flow of fuel passes through flow control valve FV-011 and on to Filter F-001 to remove any solids suspended in the fuel prior to entering Supplier No. 1 Meter Run MR-001. MR-001 uses a turbine flow meter to accurately measure the volumetric flow of the liquid entering the West Leg of the pipeline. A densitometer on the metering skid measures the density of the liquid so that the mass flow into the pipeline can be calculated from the volumetric flow given by the turbine flow meter.
Motor-operated valves MV-011 and MV-2000 are located at the inlet of the Filter F-001 and at the outlet of Meter Run No. 1 MR-001 so that the flow from Supplier No. 1 can be stopped in case of normal shutdown or in case of an emergency. The piping for the supply line and the meter run are located at grade.
West Leg
Hydrocarbon liquid from Supplier No. 1 Meter Run MR-001 flows through piping and enters the beginning of the West Leg of the Liquid Pipeline just upstream of isolation valve MV-2001 which is located at grade. The Western Leg of the Liquid Pipeline system is 16 inches in diameter and 50 miles. It runs at approximately a constant elevation from beginning to end. The pipeline runs underground after MV-2001 and is 8 feet under the surface of the land.
There are four more motor operated isolation valves, MV-2001, MV-2002, MV-2003 and MV-2004 on the Western Leg. The pipeline emerges from underground at each isolation valve and returns underground after the valve. This allows the valve to be accessed at the surface for maintenance and repair. A gate valve is used for each valve with a motor actuator. The motor opens or closes the valve in 30 seconds. These valves are used to isolate sections of the pipeline in case of an emergency (e.g. a leak or fire near the pipeline property) or maintenance on a section of the pipeline.
Note that the pipeline MOVs normally are outfitted with an equalization line and hand valves in parallel to the MOV at the valve station in case there is very high differential pressure across the MOV when it is closed. The equalization line is used to manually direct liquid to the low-pressure side of the valve. This is done because a large differential pressure across the MOV will inhibit the opening of the disk inside the gate valve assembly. The force of the motor pulling the disk can often result in damage to the seal trim on the disk. Opening the equalization line reduces the pressure difference across the MOV to avoid damage when opening the MOV. The equalization line and its valves are not simulated. It is assumed these local operations are performed as necessary.
West Leg PIG Launcher L-001 is located at the beginning of the Western Leg of the pipeline above grade just before MV-2001. A small supply line from MR-001 passes through hand valve HV-013A (a gate valve) to provide liquid to push the PIG (pipeline inspection gizmo) out of the launcher and into the Western Leg as needed. A PIG can be used for inspection and for cleaning the pipeline, depending on its design. The PIG launcher consists of a pipe with a larger diameter than that of the Western Leg and is fitted with a swing cover plate at the larger end for loading the PIG. On the simulator, loading of the PIG by swinging the cover plate and inserting the PIG is accomplished with HV-013C. These operations are always done in the field but are presented to the operator on the simulator so that the basic operation of PIG loading and launching can be practiced. The launcher also has a transition piece that tapers to the diameter of the pipeline. Hand valve HV-013B isolates the launcher from the Western Leg.
The Western Leg is constructed such that the PIG can travel smoothly in the liquid flowing through the pipeline to the West Leg PIG Receiver R-001 at the end of the Western Leg. Normally all the valves for L-001 are closed. Note that a PIG launcher also has vent, drain and equalization valves along with pressure gauges for local operation (draining, venting, purging, filling). These are excluded on the simulator and all appropriate local operations for loading and launching the PIG are assumed to be performed correctly.
After the last segment of the West Leg, the pipeline emerges to the surface and enters the West Leg PIG Receiver R-001. R-001 is essentially a mirror image of West Leg PIG Launcher R-001. Flow from the pipeline is routed into R-001 through HV-014A. R-001 is also outfitted with a small line and valve HV-104B to allow liquid flow into R-001 so that the PIG will enter.
The main flow from the Western Leg diverts through a barred tee upstream of HV-014A and is sent to Pump Station No. 1. Barring (lengths of steel bar) on the tee prevents the PIG from flowing into the side port of the tee. Liquid flow from R-001 through HV-014B is combined with the flow to Pump Station No. 1. Normally all the valves for R-001 are closed. Note that there is no unloading function for R-001 because this is assumed done in the field after a PIG is received in R-001.
Pump Station No. 1 Controls
Pump Station No. 1 consists of two variable speed centrifugal pumps that operate in series. The purpose of Pump Station No. 1 is to boost the pressure of the liquid coming from the West Leg of the pipeline so that the flow rate of liquid through the West Leg can be maintained as the liquid travels on to the Central Leg. The operation of the pump station is highly automated for purposes of ease of operation and improved safety.
Liquid normally flows from the West Leg to Pump Station No. 1 through the pump station’s inlet motor operated valve (MOV) MV-2005I. Direct flow from the West Leg to the Central Leg is made by bypassing the Pump Station No. 1 which will open the mainline MOV MV-2005M. Liquid flows from MV-2005I through Filter F-101 which removes any suspended solids that may be present in the liquid from the West Leg.
The liquid normally flows from F-101 to No. 1 Booster Pump P-101A. P-101A is outfitted with suction and discharge valve MOVs (MV-101AS and MV-101AD). Both valves are open when P-101A is running. P-101A is a centrifugal pump outfitted with an electric motor powered by a variable frequency drive (VFD). In normal operation, the speed of P-101A is adjusted to maintain the inlet pressure to Pump Station No. 1. The VFD adjusts the frequency of the electric power to the motor and therefore adjusts the speed of P-101A. In case the VFD is not in operation, electric switchgear will directly connect power from the utility supply to the motor and it will run at full speed.
In case P-101A is not in service, liquid flow from F-101 will automatically bypass P-101A through a check valve in the bypass line.
Flow continues from P-101A or its bypass line to No. 1 Booster Pump P-101B. P-101B is identically outfitted to P-101A, including a bypass line with a check valve. Normally, P-101B’s motor is off and the flow from P-101A bypasses P-101B through the check valve. In case additional boosting of pressure is needed, both P-101A and P-101B can be operated at the same time.
The flow from P-101B or its bypass line then flows through control valve CV-101. Normally CV-101 is fully open when pump is running. In case the VFD is out of service the pump motor(s) run at full speed and control of the station’s pressures are then accomplished by adjusting the position of CV-101. Flow from CV-101 passes through the pump station’s outlet MOV MV-2005O.
Central Leg
Hydrocarbon liquid from Pump Station No. 1 flows through piping and enters the beginning of the Central Leg of the Liquid Pipeline just upstream of isolation valve MV-2006 which is located at grade. The Central Leg of the Liquid Pipeline system is 16 inches in diameter and 50 miles long. It runs at approximately a constant elevation from beginning to end. The pipeline runs underground after MV-2006 and is 8 feet under the surface of the land. There are four more motor operated isolation valves, MV-2007, MV-2008, MV-2009 and MV-2010 on the Central Leg. The pipeline emerges from underground at each isolation valve and returns underground after the valve. This allows the valve to be accessed at the surface for maintenance and repair. A gate valve is used for each valve with a motor actuator. The motor opens or closes the valve in 30 seconds. These valves are used to isolate sections of the pipeline in case of an emergency (e.g. a leak or fire near the pipeline property). MV-2008 is located on the tie-in line from Supplier No. 2 Meter Run MR-002 which is located mid-way between MV-2007 and MV-2009.
Central Leg PIG Launcher L-002 is located at the beginning of the Central Leg of the pipeline above grade just before MV-2006. L-002 PIG operations are not simulated.
After the last segment of the Central Leg the pipeline emerges to the surface and enters the Central Leg PIG Receiver R-002. R-002 PIG operations are not simulated.
The flow from the Central Leg is sent to Pump Station No. 2.
Supplier No. 2
Supplier No. 2 supplies hydrocarbon fuel (normally gasoline) to the Central Leg of the pipeline. The flow of fuel passes through flow control valve FV-021 and on to Filter F-002 to remove any solids suspended in the fuel prior to entering Supplier No. 2 Meter Run MR-002. MR-002 uses a turbine flow meter to accurately measure the volumetric flow of the liquid entering the Central Leg of the pipeline. A densitometer on the metering skid measures the density of the liquid so that the mass flow into the pipeline can be calculated from the volumetric flow given by the turbine flow meter.
Motor-operated valves MV-021 and MV-2008 are located at the inlet of the Filter F-002 and at the outlet of Meter Run No. 2 MR-002 so that the flow from Supplier No. 2 can be stopped in case of normal shutdown or in case of an emergency. The piping for the supply line and the meter run are located at grade. Flow from MR-002 continues through a short run of pipe above grade to the tie-in with the Central Leg.
Pump Station No. 2 Controls
Pump Station No. 2 is identical in configuration to Pump Station No. 1. It consists of two variable speed centrifugal pumps that operate in series. The purpose of Pump Station No. 2 is to boost the pressure of the liquid coming from the Central Leg of the pipeline so that the flow rate of liquid through the Central Leg can be maintained as the liquid travels on to the East Leg. The operation of the pump station is highly automated for purposes of ease of operation and improved safety.
Liquid normally flows from the Central Leg to Pump Station No. 2 through the pump station’s inlet motor operated valve (MOV) MV-2011I. Direct flow from the Central Leg to the East Leg is made by bypassing the Pump Station No. 2 which will open the mainline MOV MV-2011M. Liquid flows from MV-2011I through Filter F-201 which removes any suspended solids that may be present in the liquid from the Central Leg.
The liquid normally flows from F-201 to No. 2 Booster Pump P-201A. P-201A is outfitted with suction and discharge valve MOVs (MV-201AS and MV-201AD). Both valves are open when P-201A is running. P-201A is a centrifugal pump outfitted with an electric motor powered by a variable frequency drive (VFD). In normal operation, the speed of P-201A is adjusted to maintain the inlet pressure to Pump Station No. 2. The VFD adjusts the frequency of the electric power to the motor and therefore adjusts the speed of P-201A. In case the VFD is not in operation, electric switchgear will directly connect power from the utility supply to the motor and it will run at full speed.
In case P-102A is not in service, liquid flow from F-201 will automatically bypass P-201A through a check valve in the bypass line. Flow continues from P-201A or its bypass line to No. 2 Booster Pump P-201B. P-201B is identically outfitted to P-201A, including a bypass line with a check valve.
Normally, P-201B’s motor is off and the flow from P-201A bypasses P-201B through the check valve. In case additional boosting of pressure is needed, both P-201A and P-201B can be operated at the same time.
The flow from P-201B or its bypass line then flows through control valve CV-201. Normally CV-201 is fully open when pump is running. In case the VFD is out of service the pump motor(s) run at full speed and control of the station’s pressures are then accomplished by adjusting the position of CV-201. Flow from CV-201 passes through the pump station’s outlet MOV MV-2011O.
East Leg
Hydrocarbon liquid from Pump Station No. 2 flows through piping and enters the beginning of the East Leg of the Liquid Pipeline just upstream of isolation valve MV-2012 which is located at grade. The East Leg of the Liquid Pipeline system is 16 inches in diameter and 50 miles long. It runs at approximately a constant elevation from beginning to end. The pipeline runs underground after MV-2012 and is 8 feet2.40 meters under the surface of the land. There are four motor operated isolation valves, MV-2013, MV-2014, MV-2015 and MV-2016 on the East Leg. The pipeline emerges from underground at each isolation valve and returns underground after the valve. This allows the valve to be accessed at the surface for maintenance and repair. A gate valve is used for each valve with a motor actuator. The motor opens or closes the valve in 30 seconds. These valves are used to isolate sections of the pipeline in case of an emergency (e.g. a leak or fire near the pipeline property). MV-2014 is located on the tie-in line from Supplier No. 3 Meter Run MR-003 which is located mid-way between MV-2013 and MV-2015.
East Leg PIG Launcher L-003 is located at the beginning of the East Leg of the pipeline above grade just before MV-2012. L-003 PIG operations are not simulated.
The flow from MV-2016 flows through the last segment of the East Leg to the Storage and Terminus areas of the liquid pipeline.
Supplier No. 3
Supplier No. 3 supplies hydrocarbon fuel (normally gasoline) to the East Leg of the pipeline. The flow of fuel passes through flow control valve FV-031 and on to Filter F-003 to remove any solids suspended in the fuel prior to entering Supplier No. 3 Meter Run MR-003. MR-003 uses a turbine flow meter to accurately measure the volumetric flow of the liquid entering the East Leg of the pipeline. A densitometer on the metering skid measures the density of the liquid so that the mass flow into the pipeline can be calculated from the volumetric flow given by the turbine flow meter.
Motor-operated valves MV-031 and MV-2014 are located at the inlet of the Filter F-003 and at the outlet of Meter Run No. 3 MR-003 so that the flow from Supplier No. 3 can be stopped in case of normal shutdown or in case of an emergency. The piping for the supply line and the meter run are located at grade. Flow from MR-003 continues through a short run of pipe above grade to the tie-in with the East Leg.
Storage Tank
Hydrocarbon liquid flows from MV-2016 on the East Leg through the last segment of approximately 10 miles. The East Leg emerges to the surface and enters the East Leg PIG Receiver R-003. R-003 PIG operations are not simulated. Flow from the East Leg normally flows past R-003 to the Terminus of the pipeline located a short distance from R-003.
Upstream of R-003 there are takeoff and return lines to the Storage Tank on the East Leg. The takeoff and return lines are 8 inches in diameter and will not pass a larger diameter PIG from the East Leg. The takeoff line passes through MOV MV-701 and continues on through pressure control valve PV-701 and into Storage Tank T-701. Normally there is no takeoff flow from the pipeline. Hydrocarbon liquid will be diverted from the East Leg to T-701 in case the pressure at the end of the East Leg becomes too high. This usually happens if the Terminus section of the pipeline is shut down or needs to operate at reduced capacity. T-701 can hold approximately 2 hours of design pipeline flow (50 MBPD) or approximately 4,200 BBL of liquid.
The Pipeline Return Pumps P-701A/B are identical centrifugal electric motor-driven pumps that take suction from the base of Storage Tank T-701 and return hydrocarbon liquid to the East Leg of the pipeline near its end. The pumps are designed to return liquid to the pipeline at flow rates up to 30 MBPD as needed. Normally P-701A/B are not operating. Flow from the discharges of P-701A/B is combined and pass through flow control valve FV-702 and through isolation MOV MV-702. Flow then passes to the East Leg of the pipeline.
Terminus
The Terminus is the very end of the liquid pipeline at the end of the East Leg. All the equipment is above grade. Flow from the East Leg Filter F-004 to remove any solids suspended in the fuel prior to entering Terminus Meter Run MR-004. MR-004 uses a turbine flow meter to accurately measure the volumetric flow of the liquid taken from the East Leg of the pipeline. A densitometer on the metering skid measures the density of the liquid so that the mass flow into the pipeline can be calculated from the volumetric flow given by the turbine flow meter. Flow then continues from MR-004 through pressure control valve PV-041. Motor-operated valves MV-2017 and MV-041 are located at the inlet of the Filter F-004 and at the outlet of Terminus Meter Run MR-004 so that the flow from the East Leg of the pipeline can be stopped in case of normal shutdown or in case of an emergency. Flow from MR-004 continues through a short run of pipe above grade to piping that transfers the liquid to a downstream tank farm.