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CHAPTER 9

PIPELINE OPERATIONS

Section I. Duties of Personnel

CHIEF DISPATCHER

The chief dispatcher is usually the petroleum distribution officer in a petroleum pipeline and terminal operating battalion or petroleum group. The dispatcher has operational control over the whole pipeline system. As a rule, the dispatcher's office is normally located at the headquarters responsible for the control of the pipeline distribution system. The duties of the shift dispatchers are the same as those of the chief dispatcher. Shift dispatchers control operations in the name of the chief dispatcher.

Required Knowledge

The chief dispatcher must know--

  • Knowledge and Skills, as required, by the Spill Prevention Control and Countermeasures (SPCC) Plan, for the particular installation and site over which the dispatcher has operational control.
  • Capacity of storage tanks at each installation.
  • Line fill and throughput for each section of pipeline.
  • Hydraulics, including how to determine the normal working pressure for each section of line and the maximum discharge pressure that each pump station can develop.
  • Number and location of pump stations.
  • Line profile and the critical points in the line.
  • Stock status and daily needs.
  • Physical and chemical properties of each petroleum product pumped.
  • Equipment controls and input and take-off rates.
  • Safety features for protection of equipment and products pumped.
  • Safety requirements for personnel and personal protective equipment (PPE) necessary for specific operations.
  • Procedures for blending in additives and interfaces.

Required Determinations

The chief dispatcher must determine--

  • Type of product to be pumped.
  • Destination of each batch.
  • Amount of each product in each batch.
  • Estimated size of interfaces and estimated times of arrival of interfaces at pump stations and terminals.
  • Starting and stopping times of all pumping operations.
  • Type of cut to be made with each interface.
  • Pipeline pump station pressures and flow rates.
  • Condition of the interior, corrosion inhibitors, and scraper program.

Required Actions

The chief dispatcher must--

  • Coordinate the development of monthly and daily schedules.
  • Relay daily pumping orders to district dispatchers.
  • Keep necessary records based on hourly reports from pump stations, tank farms, dispensing stations, and other installations.
  • Keep records of fuel received into the pipeline system, fuel delivered to installations along the line, fuel left in the system, and fuel lost.
  • Report daily information to higher headquarters.

Chief Dispatcher's Office

Personnel in the scheduling and dispatching sections of the office of the chief dispatcher have various duties. These duties are described below:

Scheduling Section

Personnel in the scheduling section prepare the monthly pipeline schedules which are based on requirements to maintain stock levels. They also prepare daily pumping schedules from the monthly schedule. The daily schedules are usually prepared a week in advance.

Dispatching Section

Personnel in the dispatching section start, adjust, and stop all pumping operations. To do this, they issue daily pumping orders to the district dispatchers. These orders are based on the daily and monthly schedules and take into consideration any last minute changes or emergency requirements.

DISTRICT DISPATCHERS

District dispatchers are located at subcontrol headquarters in the pipeline system. Each controls pumping operations in their district according to the instructions of the chief dispatcher. Hourly pumping and delivery reports are sent to the chief dispatcher. The hourly reports include barrels pumped from or received into each storage location, corrected to 60° F. Also the report includes suction and discharge pressures and RPMs for operating pumps, batch changes, and flow rates. A district dispatcher has certain freedom of action in emergencies. In the case of a line break, fire, or other interruption, the district dispatcher--

  • Isolates the affected section of the line.
  • Diverts upstream pumping into empty storage tankage or orders the line shut down.
  • Halts pumping in the broken section of the pipeline.
  • Instructs the terminal station downstream from the break to begin drawing fuel from its tankage and to continue pumping or shut down.
  • Informs the chief dispatcher at once of the shutdown.
  • Identifies the shutdown section and reports the disposition and amount of flow to and from available tankage.

Section II. Pipeline Communications System

DESCRIPTION

An efficient communications system is a must for the operation and maintenance of military pipelines. The system must be separate, continuous, and dependable. The communications system must have-

  • High-quality transmission to keep errors to a minimum.
  • Enough channels or circuits to carry the traffic load.
  • Prompt connections to avoid delays.
  • Immediate alternate systems so there will be no interruptions in pipeline operations.

EQUIPMENT AND USE

Teletypewriters, telephones, and radio teletypes are the main items of equipment in the system. Radios provide communication between all dispatchers and between pump stations. Radio communication is also used to maintain contact with maintenance support teams and mobile air and land patrols. The communications system begins at the petroleum pipeline and terminal operating company. Each company uses teletypewriters, radios, telephones, and radio teletypes to control operations. Telephones are used by company elements for administration purposes. They are also used for similar purposes by battalion and group headquarters. As a rule, all pump stations and tank farms have the same teletypewriter and telephone capabilities. Standby radio communications are provided between adjacent pump stations.

Teletypewriter Service

This is furnished on a party-line basis to all pump stations and tank farms in each district. Each end of the party line includes the subcontrol stations at either end of the district. The circuit at each pump station ends in a page-printing teletypewriter.

Party Line Telephone System.

This is provided to all pump stations and tank farms in the district. It is also provided to the subcontrol station at each end of the district. Each station on the party line is given an identifying code ring.

SYSTEM EXPANSION AND CONTROL

The system is expanded when there are petroleum pipeline and terminal operating battalions and petroleum group headquarters. The system is controlled by the chief dispatcher. He uses the system to control the flow of products through the pipeline.

SIGNAL OFFICER

A signal officer is assigned to petroleum battalion or group headquarters. One of his major functions is to coordinate with appropriate signal agencies to ensure that they provide the required support. The signal officer has staff supervision over assigned and attached signal troop units. He supervises internal communication support activities for the headquarters. He also inspects subordinate units to ensure equipment is properly maintained and operated. The signal officer assigned to a petroleum group headquarters takes part in the communications planning of the petroleum distribution system. This duty may include--

  • Preparation of signal plans and policies for the headquarters and its subordinate operating units.
  • Acquisition and allocation of required circuits and frequencies.
  • Preparation of plans for emergency communication.
  • Designation of alternate means of communications to be used when the existing systems are disrupted.

CHIEF DISPATCHER CONTROL STATION

The chief dispatcher is normally positioned away from the first district dispatcher. The first district dispatcher is usually at the harbor end of the pipeline system. However, the chief dispatcher control station may be combined with the first district dispatcher subcontrol station if needed. The chief dispatcher has a tape-printing and transmitting teletypewriter, a telephone, and radio facilities. As a rule, the teletypewriter is used as the main method of communication.

  • The chief dispatcher has a direct teletypewriter channel to the district dispatcher at each subcontrol station. This channel is on a party-line basis as long as there are no more than nine subcontrol stations in the pipeline system. The chief dispatcher has a teletypewriter switchboard in which circuits to district dispatchers end. The switchboard allows the chief dispatchers to contact any or all district dispatchers separately or in any combination. It also allows district dispatchers to contact adjacent district dispatchers.
  • The chief dispatcher has a telephone that allows him to talk to subcontrol stations 1 and 2.
  • The chief dispatcher also has mobile, high-frequency radio facilities. These facilities may be integrated into the common system at the chief dispatcher control station or any subcontrol station. The radio has a radio-teletypewriter and voice capability. This gives the chief dispatcher another means of contacting district dispatchers on a net operation basis. The radio system may be operated by remote control from the office of the chief dispatcher and the dispatcher at each district.
  • The chief dispatcher notifies all pump stations of an impending shipment by having the message punched on a teletypewriter tape. The message is sent to all district dispatchers at the same time. On receipt of the message, district dispatchers decide if it is intended for all pump stations. The district dispatchers then transmit the message through their respective communication circuits. If a circuit to any district station is out of order, the chief dispatcher uses the radio equipment for communication.

DISTRICT DISPATCHER SUBCONTROL STATIONS

All district dispatcher subcontrol stations have teletypewriters and telephones. As a rule, the teletypewriter is used as the main system of communications and the telephone as the secondary system. The system is organized as described below.

  • Each subcontrol station has a direct teletypewriter channel to the chief dispatcher. This channel is provided on a private-line basis unless the chief dispatcher decides otherwise.
  • Subcontrol stations 1 and 2 have direct telephone lines to the chief dispatcher.
  • Each subcontrol station has a small telegraph and telephone switchboard. This switchboard terminates circuits coming into and within the district. This arrangement allows the operation to be flexible. Access to through circuits allows individual district dispatchers to function as the chief dispatcher in an emergency.
  • All pump stations and tank farms in a district communicate through a party line telephone channel with manual code ringing and a party line teletypewriter channel. These channels end in the subcontrol stations at either end of the district. The teletypewriter circuit at each district station ends in a teletypewriter that can receive and send both tape and page copy.
  • Relay services are provided by the subcontrol stations. These services are mostly the relaying of chief dispatcher channels to distant subcontrol stations. Services are provided to other stations on the pipeline system by request.
  • Each subcontrol station has mobile radio equipment. This equipment allows the subcontrol station to contact the chief dispatcher and any other subcontrol station. The radio equipment may be used to communicate if the party line teletypewriter circuit is interrupted.

Section III. Schedules

Scheduling Factors

Scheduling is planning the movement of bulk petroleum products by pipeline from the base terminal to intermediate terminals and pipe head terminals. Before products can be scheduled for movement, the chief dispatcher must determine when and where specific products will be required and how much storage space is available. He must also know how long it will take for the product to reach its destination after it has been started through the pipeline. Past experience is the best way to determine daily requirements throughout the pipeline system. With the above factors in mind, the chief dispatcher prepares consumption graphs. These graphs show projected consumption and deliveries. Under the supervision of the chief dispatcher, the scheduling and distribution sections prepare a monthly pipeline schedule and a daily pumping schedule.

CONSUMPTION GRAPH

The chief dispatcher keeps a consumption graph for each product handled at each storage point. Each terminal keeps similar graphs for large volume users. The graphs are valuable for showing present and future stocks and storage positions. They also show trends in consumption. Sudden increases or decreases in consumption are quickly recognized and can be reflected in scheduling. A consumption graph must show the total barrels of any given product for each terminal or storage location. A separate graph should not be prepared for each tank. Figure 9-1, is a consumption graph for diesel. Information for this graph is given below.

  • Storage capacity for the product in thousands of barrels (vertical axis) is plotted against time in monthly intervals (horizontal axis). Days are figured from 0001 of one day to 0001 of the next.
  • Allowance for vapor space is 5 percent of the total storage capacity. This is reflected at the top of the graph.
  • Safety level is shown at the bottom. The safety level is normally determined (at theater level) based on collective data.
  • Calculated issues and receipts are shown by a broken line. Actual issues and receipts are shown by a solid line. All receipts are shown by a vertical line at the end of the day. Daily issues to local customers and pipeline issues are shown on the same graph.
  • Allowances must be made for tank cleaning and repairs. The reduced storage capacity is subtracted from the total capacity.
  • Differences in stock on hand from day to day show the rate of consumption. The average consumption rate from past experiences is used to plan for future issues. Based on this projected consumption rate, the system must be replenished by pipeline.

Figure 9-1. Consumption graph

MONTHLY PIPELINE SCHEDULE

The monthly pipeline schedule as shown in Figure 9-2, shows the programmed movement of products through the pipeline. The products required for the 30-day period must be determined. Then a schedule can be prepared to compute the time it will take for a product to reach its destination after it has started into the pipeline. This schedule is merely a graph which shows line capacity in barrels (distance) plotted against time (hour). It is prepared on a sloping tabletop, which can be equipped with a full-length parallel rule. It is best to use an adjustable protractor with the parallel rule to ensure that the flow is plotted correctly. Information on this graph is given below.

  • Before the graph is made, the number of hours a line is to be pumped each day must be determined. Time is shown from the beginning to the end of a given working day. The chart is drawn with the vertical axis showing line fill.
  • The horizontal axis is drawn to show the time period.
  • Terminals are located on the chart by their respective line fill distance downstream from the base terminal. The terminals are plotted vertically.
  • Each batch is labeled by product and batch number. Each type of product is marked on the graph with a different color.
  • The distance in barrels divided by the pumping rate equals the number of hours it will take for a given batch to reach a designated place.
  • The slope of the throughput lines stays constant when there is no intermediate stripping and when the pumping rate stays the same. Stripping is when all or part of one or more batches is taken off the main pipeline at an intermediate terminal.
  • When products are taken into a terminal and half of the pipeline is shut down, this is plotted on the monthly pipeline schedule. A dotted line on the horizontal time axis shows the time the pipeline is shut down. A dotted line on the vertical axis shows the portion of the pipeline to be shut down. A second vertical dotted line shows when the pipeline goes back on stream. It should be noted on the schedule that this is a static condition.
  • Stripping of product at a terminal is shown in the same manner as a static condition--with horizontal and vertical dotted lines. It is noted in the block formed by the dotted lines that a stripping action is taking place.
  • The vertical lines represent terminals and stations. The points at which the sloping lines intersect the vertical lines show scheduled arrival times.
  • When all of the throughput lines have been drawn, the graph represents all scheduled pumping and delivery operations for the month.

Figure 9-2. Monthly pipeline schedule

DAILY PUMPING SCHEDULE

The daily pumping schedule as shown in Figure 9-3 is used as a basis for preparing pumping orders. It is an abbreviated tabular form of the monthly schedule for each day concerned. This schedule shows changes and emergency needs. It is usually prepared a week in advance so that the dispatching section can have a week's supply. The dispatching section uses the daily pumping schedule to prepare the graphic progress chart and the daily pumping order.

Figure 9-3. Daily pumping schedule

Section IV. Line Operations

TESTING OPERATIONS

The chief dispatcher keeps a week's supply of daily pumping schedules. He uses them to arrange with the base terminal to test the products before pumping begins. They are tested according to MIL-HDBK-200. Test results are recorded on DA Form 2077 Arrangements are also made for line sampling and testing while the product is enroute. This is done to mark the progress and position of interfaces. Instructions for testing and disposing of interface are given to the terminals where they are to be taken off.

PUMPING OPERATIONS

The chief dispatcher decides the specific times batches are to be pumped into the line. All stations along the line are told of the starting time, amount of product, route, and destination. The input station reports every hour on cumulative barrels pumped, temperatures, pressures, and batch numbers. Pump stations along the line report every hour on line and atmospheric temperatures, pressures, product code, and batch number. This information is recorded on DA Form 4193 as shown in Figure 9-4. The reports are sent to the district dispatchers who, in turn, send the reports to the chief dispatcher. Pump stations are told of the expected arrival time of scrapers that may be in the line.

OPERATION REPORTS

Operation reports cover hourly pumping and delivery data from the various pipeline pump stations. These reports are sent to the appropriate district dispatcher. The reports provide a check on the operation of the line. The chief dispatcher decides the progress of batches and the position of interfaces by using the various operation reports. This information is recorded on the daily pumping record. Some of the information is used along with the graphic progress chart or with the stream tape. Discrepancies between barrels pumped and barrels delivered must be investigated. The pipeline day begins at midnight. At that time, the chief dispatcher sends a time signal to regulate all clocks in the system. The first report is made at 0100. Station 1 reports first, and all others follow in order. The report from a branch line takeoff station follows that from the main line station where the branch begins. Reports from input stations, way stations, and takeoff stations will differ in content. Reports need be no more than a single teletype line. They are letter and figure-coded to save space and time. Data should be arranged in sequence. Then, they will coincide with station logs and dispatcher's pumping record. More station reports and information are given below.

Input Station Report

An input station provides various data to the dispatcher. These data include--

  • Batch number and product code.
  • Tank number from which fuel is being pumped.
  • Line temperature.
  • Atmospheric temperature.
  • Suction pressure.
  • Station discharge pressure.
  • Any change in gravity.
  • Barrels pumped in last hour, corrected to 60° F.
  • Cumulative barrels pumped since midnight, corrected to 60° F.

Pump Station Report

A pump station provides various data to the dispatcher. These data include--

  • Batch number.
  • Line temperature.
  • Atmospheric temperature.
  • Suction pressure.
  • Discharge pressure of each pump operating.

Figure 9-4. DA Form 4193 (Petroleum Products- Pump Station Hourly Operations Record)

Figure 9-4. DA Form 4193 (Petroleum Products-Pump Station Hourly Operations Record) (continued)

Takeoff Station Report

A takeoff station provides various data to the dispatcher. These data include--

  • Batch number.
  • Tank number into which fuel is being pumped.
  • Product or grade (API gravity).
  • Observed temperature.
  • Sample number.
  • Cumulative barrels received since midnight, corrected to 60° F.

Additional Information

Other needed information will be sent hourly to the chief dispatcher from the district dispatchers. Data on rate of flow, position of interfaces, and inputs and takeoffs from the main line should be sent to the chief dispatcher. He uses these to keep a current plot on the graphic progress chart.

Reporting Instructions

There are various instructions that stations use for reporting data to the dispatcher. These instructions are given below.

  • Station 1 puts its report on the teletype promptly on the hour.
  • All other stations stand by to report in sequence.
  • Any station not able to report in sequence must report after all other stations have reported.
  • All information not pertinent to the report is excluded.
  • The sequence of reports is interrupted only by emergencies.
  • Any station not reporting is contacted by the chief dispatcher.

Section V. Dispatching Records And Controls

Daily Pumping Record

The daily pumping record as shown in Figure 9-5, is known also as the operation sheet or train sheet. The format may be changed locally to suit local needs or the requirements of higher headquarters. Basically, the record details operations of the whole line in the same way the station log details station operations. The chief dispatcher uses data in hourly operations reports to keep the daily pumping record. The vertical axis shows a complete pipeline day beginning at 0000 and ending at 2400. The horizontal axis is divided into separate sections for each pump station and terminal in the pipeline system. Station sections are labeled by station number or location. The first section is used for the base terminal. Other stations and terminals follow from left to right downstream. A suggested format is described below.

Figure 9-5. Suggested format for daily pumping record

Information Recorded

The tank column next to the left-hand time column is used to record the number of the tank from which fuel is being pumped. Cumulative input is the hourly batch total of fuel pumped. The initial station suction pressure is that supplied by gravity or a feeder pump. Individual pump discharge pressures and RPMs are recorded to show any problems. RPMs should be the same for all pumps operating properly. Suction pressure for pump 1 only is recorded. This is because the discharge pressure of pump 1 is the suction pressure of the next pump. Cumulative takeoff at depots and terminals is the hourly total of deliveries from the line. Rate of flow beyond a takeoff terminal should be no more than the amount pumped into the pipeline minus the rate of takeoff. Therefore, rate of flow beyond a full-stream takeoff must be zero. The tank column for delivery terminals is for the number of the tank receiving product from the line. Temperatures also help samplers to see gravity changes. A section for remarks can be placed below each station section of the format. Batch numbers and changes, switching times, scraper launchings and arrivals, and other needed information may be put in the remarks section.

Preparation and Posting

The daily pumping record is prepared by the dispatcher on duty at midnight and at 0700 or 0800. Postings for 2400 on the old sheet are carried over to 0000 on the new sheet. Properly arranged station logs help the dispatcher when he prepares and posts the daily pumping record. Batch changes, showing time of first and final change (gravity or color) and rate of flow, are posted in the remarks section. Discharge pressures should be monitored closely. Any drop in discharge pressure could show a line tap or break. When a batch is completed at the terminal, the batch number and barrels pumped since midnight should be shown under the respective section. The number of barrels short or over for each hour should be entered in the end point block. The pipeline is over (black) when total deliveries exceed total pumping. The pipeline is short (red) when the total pumping exceed the total deliveries. A cumulative (over or short) is carried for a complete day only. The cumulative total for each shift can be checked by subtracting the hourly deliveries from the hourly pumping since midnight.

GRAPHIC PROGRESS CHART

The graphic progress chart as shown in Figure 9-6, shows the position of batches and their progress through the pipeline. It is prepared one day in advance. The chart cover a 24-hour period.

Preparation

The chart is prepared on a sloping table using a full-length parallel rule, a flow rate scale, and a protractor or adjustable triangle. Any scale can be used. The chart is prepared as follows:

  • Hours are shown on the vertical axis.
  • Line fill terminals and pump stations are shown on the horizontal axis. Line fill is shown to the right of the midpoint, zero barrels. Scheduled input is shown to the left of the midpoint. The midpoint represents the base terminal.
  • Terminals, stations, and branch lines are shown on the vertical lines at the corresponding downstream line fill distance from the input point or base terminal.
  • To determine when a new product is to be started into the line, a horizontal line is drawn left from the entry point (base terminal). The line is drawn a distance equal to the number of barrels scheduled to enter. An adjustable triangle that has been preset for the desired rate of flow is used to draw a sloping, broken line from the end of the quantity line back to the base terminal time line. The point where the broken line crossed the base terminal time line shows the time that the new product must be started.
  • A solid sloping line is extended to the right from the base terminal time line at the same rate of flow. The degree of slope of this line shows the pumping rate of the throughput line. If the terminal is told to strip product from the pipeline, the slope of the throughput line must be changed. The stripping action is shown by a broken vertical line.
  • Shutdown of the line is shown by a broken horizontal line.
  • The points at which the sloping lines intersect the vertical lines (terminals and stations) show scheduled arrival times.

Figure 9-6. Graphic progress chart

Use

The chart is put in use at midnight. The dispatcher transfers batch positions from the bottom of the previous day's chart to the top of the new chart. Actual positions of a given batch are determined by hourly deliveries at terminals and the reported passing of interfaces. When batches are moving ahead of or behind schedule, the dispatcher can adjust the chart to show the change of the flow rate. He draws a new broken flow rate line to project delivery. As a rule, the desired action is to adjust the flow rate temporarily to put the batch on schedule. Each hour, the dispatcher draws horizontal lines using the appropriate color for each batch to show the position of the different fuels in the line. When all the batch lines have been drawn, the chart represents all scheduled pumping and delivery operations for the day.

DAILY PUMPING ORDER

There is no set format for the daily pumping order. Table 9-1, page 9-18, shows a sample pumping order. General guidelines for preparing the order are as follows:

  • Time is shown in chronological sequence. Definite times should be shown for specific actions.
  • Locations are shown from the base terminal through intermediate terminals and pump stations to the head terminal.
  • Specific orders must be given for the respective terminals and stations. Orders should be stated briefly and clearly.
  • All product and batch numbers must be designated.
  • Amounts of products to be handled and type of interface cuts must be specified.

STREAM TAPE OPERATION

Stream tape operation is another way to show the movement of fuels through the pipeline. It allows the dispatcher to determine instantly and accurately the location of any batch, buffer, dye, plug, or scraper. Arrival time at any terminal or branch line can be estimated easily. The operation and items needed are described below.

Dispatching Board

This board is needed for the stream tape operation. It is a long worktable that parallels a pipeline profile mounted on the wall above it. Components of the board include a system of markers to show stations and terminals, the stream tape, and the guides or track in which the tape moves. There are separate tracks and tapes for each pipeline in the system.

Station Markers

The station markers may be movable metal or plastic pointers mounted on metal or plastic guides. The first marker at the left or upstream end of the board represents the base terminal or input points. Markers going to the right or downstream represent all other stations and terminals. The markers are spaced at distances and to the same scale as the pipeline profile on the wall above.

Stream Tape

The paper tape is 4 to 6 inches wide. It is supplied in rolls. The rolls are mounted under the left end of the dispatching board. The tape is fed through guides at the base terminal marker. The top edge of the tape has a printed scale. The scale shows the line fill at the proper number of barrels per inch. In commercial use, the bottom edge may have one or two colored bands. The upper band stands for the shipper, and the lower band stands for the product. If there is only a single band, it stands for the product.

Table 9-1. Sample format for daily pumping order

TIMES

 

LOCATION

 

DESIRED ACTION

 

0001

Base Terminal

Pump DF, batch 3-17, 8,000 barrels at 1,000 barrels per hour.

 

Pump Station 1

Pump 8,000 barrels of DF at 1,000 barrels per hour

 

Pump Station 2

Pump JP-4, batch 2-16

 

Intermediate Terminal

No action

 

Pump Station 3

Pump DF, batch 3-14

 

Pump Station 4

Pump MOGAS, batch 1-13

 

Head Terminal

Receive JP-4, batch 2-12, at 1,000 barrels per hour.

0800

Base Terminal

Switch from DF, batch 1-17, to JP-4, batch 2-18, and pump 8,000 barrels.

 

Pump Station 7

Monitor the passage of interface, the end of batch 3-17, and the front of batch 2-18. Report.

 

Pump Station 2

Monitor the passage of interface, the end of batch 2-16, and the front of batch 3-17. Report.

 

Intermediate Terminal

Prepare to receive JP-4, batch 2-16. Check passage of interface, end of batch 1-15, and front f batch 2-16. At API gravity of JP-4, open JP-4 tankage and strip 500 barrels of JP-4 for 10 hours.

 

Pump Station 3

Monitor passage of interface, end of batch 1-15, and front of batch 2-16. Report.

 

Pump Station 4

Continue to pump MOGAS, batch 1-13.

 

Head Terminal

Switch from JP-4, batch 2-3, to receive MOGAS, batch 1-13. Receive 5,000 barrels for five hours. Interface will be taken into MOGAS tankage.

1600

Base Terminal

Switch from JP-4, batch 2-18, to MOGAS, batch 1-19. Pump 8,000 barrels.

1800

Intermediate Terminal

Close JP-4 tankage at good API gravity for JP-4. Monitor passage of interface, end of batch 2-16, and front of batch 3-17.

Report.

 

Head Terminal

Start receiving MOGAS, batch 1-13, at 1,000 barrels per hour.

The number, width, and use of the posting spaces vary. Usually, the top half of the tape is used for pumping information. This includes hours, barrels pumped, batch numbers, gravities, batch totals, batch changes, dates, and other data. The bottom half of the tape is used for delivery information. This includes hours, barrels delivered, total deliveries, station designations, and opening times. The 4-inch tape is divided into four posting spaces, each three-fourths of an inch wide. The tape may be rerolled at the downstream end of the board for storage. The steam tape can be used to record a variety of operations, including pumpings, batch changes, and deliveries. The tape can be used in the following ways.

  • Pumpings. The dispatcher performs a number of the operations starting at 0001 using the daily pumping order. A color-coded tape is selected. The free end is inserted in the track. Each hour, the input point reports the number of barrels pumped. See Table 9-2, page 9-20. This information is first posted on the daily pumping record and then on the stream tape. The dispatcher uses the printed scale to measure a distance from the batch head equal to the barrels pumped in the first hour. A vertical, broken pencil line is then drawn from the proper graduation through the first posting space. The line coincides with the input station marker and shows how far the batch advanced in the first hour. Thereafter, the tape is advanced each hour by the number of barrels reported. Errors in increments will be avoided if the hourly, cumulative batch totals are scaled from the batch head. Hourly barrels and cumulative batch totals are posted in ink parallel with the vertical lines. Hours are posted on the first horizontal line. Batch numbers and gravities are posted in the space below. To estimate the arrival time of the batch head at any terminal, the dispatcher measures the distance in barrels from the batch head to the terminal marker. The distance in barrels divided by the pumping rate per hour equals the number of hours and minutes from the time of the last posting. When the first batch has been pumped, the tape is cut off at the total barrels pumped. A new tape is color coded for the next batch and trimmed to the tape. The old batch number, gravity, tank number, and total barrels are posted on the old tape. This is usually posted in the second posting space next to the junction. The new batch number, gravity, and tank number are posted on the new tape next to the junction and opposite the old data.
  • Batch Changes. Batch changes are reported as the times, in minutes, of the first and final change in color or gravity. Barrels pumped during the hour of change divided by 60 equals the rate per minute. The number of minutes past the hour of the first and final changes multiplied by the rate per minute equals the number of barrels past the hour to the head and tail of the interface. To plot these positions, the tape is advanced to the report hour. A mark is made on the scale opposite the reporting station marker. The two distances in barrels are scaled off from the index and marked. Vertical red pencil lines are then drawn from the two graduations through the first and second posting spaces. The vertical lines should be on either side of the batch head shown by the cut tape. The distance between the red lines shows the position and length of the interface. The station reporting the change and the date and time of first and final changes are posted in red pencil beside the plot.
  • Deliveries. The spliced tape continues to be advanced until another new batch is started or a delivery is to be made. When a delivery begins at some terminal, the proper batch is opposite the appropriate terminal marker on the board. The part of the tape that represents the batch is cut. The downstream end of the cut tape continues to advance in a stripping operation. It advances at a rate equal to the original throughput less the take-off rate. This is the new throughput. If a full-stream delivery is being made, the downstream end does not advance. The upstream end of the tape is advanced and is lapped over the downstream end by the number of barrels delivered. This is true for a stripping operation or a full-stream delivery. Hourly deliveries are posted in the two bottom posting spaces. Barrels delivered each hour are scaled off from the cut, and vertical pencil lines are drawn through both spaces. If there is no printed scale at the bottom of the stream tape, cumulative hourly totals should be scaled from the cut. Barrels delivered each hour are posted in ink, parallel with the vertical lines. Deliveries at different terminals from the same batch are scaled from the same cut. Alternate spaces are posted to show such deliveries. A red pencil line is drawn to mark the last delivery total. The two ends of the tape are spliced in the lapped position. When the tape is removed for storage, all laps are let out again. The tape is then replaced in its original length.

Table 9.2. Sample tabulation of receipts and deliveries

   

DELIVERIES

   

TIME

RECEIVED
FROM
INPUT
POINT

TO
TERMINAL
Y

TO
TERMINAL
Z

TOTAL

OVER
OR
SHORT

CUMULATIVE
OVER
OR
SHORT

0100

482

0

480

480

-2

-2

0200

486

0

482

482

-4

-6

0300

490

0

488

488

-2

-8

0400

502

0

500

500

-2

-10

0500

495

249

249

498

+3

-7

0600

505

248

254

502

-3

-10

0700

498

250

250

500

+2

-8

0800

510

251

261

512

+2

-6

 

(3,968)

(998)

(2,964)

(3,962)

 

(-6)

0900

512

252

260

512

0

-6

1000

507

251

257

508

+1

-5

1100

504

250

252

502

-2

-7

1200

500

249

249

498

-2

-9

1300

498

248

252

500

+2

-7

1400

495

247

251

498

+3

-4

1500

490

248

240

488

-2

-6

1600

488

242

243

485

-3

-9

 

(7,962)

(2,985)

(4,968)

(7,953)

 

(-9)

1700

492

0

494

494

+2

-7

1800

495

0

498

498

+3

-4

1900

498

0

500

500

+2

-2

2000

500

498

0

498

-2

-4

2100

505

503

0

503

-2

-6

2200

502

504

0

504

+2

-4

2300

500

249

252

501

+1

-3

2400

501

251

251

502

+1

-2

 

(11,955)

(4,990)

(6,963)

(11,953)

 

(-2)

Note: Receipts and deliveries are in barrels corrected to 60F.



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