Operations of the pumping stations and storage tanks are coordinated by a dispatcher in order to move oil through the line on schedule. Dispatching orders govern starting or stopping of units, raising or lowering of pressure, opening or closing of important valves, utilization of tankage and sampling of oil.
Whilst different crude oils may be either mixed or kept separate, refined products should be kept separate, because only a small percentage of one product can be blended with another without affecting its specifications. As long as oil in a pipeline moves fast enough, mixing between two adjacent product batches amounts to only a fraction of 1%. Recently elastomer spheroids have come into use in some pipelines for separating batches more effectively and thus reducing interfacial mixing.
The operation of a pipeline, especially one with several points of origin and destination, requires careful planning and control, for which a good system of communication is essential. Modern pipeline systems make extensive use of micro-wave transmission, telephone, telegraph and teletype for intercommunication. Control systems are widely used, including automatic remote control of pumping and take-off stations with the aid of telemetering systems. High speed digital counters are commonplace on new pipeline systems. Various types of modern computers are used to assist in planning and programming for the most economic operation.
Maintenance crews keep the lines and ancillary facilities operating at high efficiency and at minimum cost, with as little loss of operating time as possible. Pipelines, if properly welded, coated and cathodically protected, require little maintenance.
The oil industry’s need for safe, reliable and efficient pipelines to serve terminals, refineries and depots coincides with the need to ensure the safety of the public. Pipeline safety is ensured in many ways, but the main emphasis must always be on building a well-designed pipeline to the best engineering practices to avoid possible failures.
To ensure that all materials and equipment incorporated in a pipeline system are suitable and safe for the conditions under which they are used, they must comply with strict specifications and standards.
It is a standard rule for pipe manufacturers to inspect and test the tubes continuously throughout the process of manufacture. Construction is also carried out with the most careful inspection, supervision and testing procedures. In addition many types of control systems are used, including automatic remote control of pumps and valves, which largely removes human error from these operations.
In addition to visual inspection of the completed pipe, it is standard practice to test the pipeline coating electrically for breaks or pin holes, known as “holidays”, before burying the line. This entire means that the chance of a leak is infinitesimal.
Great importance is attached to fire and accident prevention.
VI. Answer the following questions.
1. Who coordinates operations of the pumping stations and storage tanks?
2 What does a dispatcher do?
3. What devices are used to prevent interfacial mixing?
4. What means of communications do modern pipelines use?
5. What do control systems include?
6. What pipelines require little maintenance?
7. In what ways is pipelines safety ensured?
8. What must comply with strict specifications and standards?
9. What is a standard rule for pipe manufacturers?
10. In what way is the construction of a pipeline carried out?
11. What must be tested before burying the line?
12. What is great importance attached to in safety measures?
