Pipehnes pipelines

Section 10 of this Handbook describes the use of orifice meters for flow measurement. In addition, orifices are commonly found within pipelines as flow-restric ting devices, in perforated pipe distributing and return manifolds, and in perforated plates. Incompressible flow through an orifice in a pipehne as shown in Fig. 6-18, is commonly described by the following equation for flow rate Q in terms of pressure drop across the orifice Ap, the orifice area A, the pipe cross-sectional area A, and the density p. 

Petroleum pipe hues before 1969 were built to ASA (now ANSI) Standard B31.4 for liquids and Standard B31.8 for gas. These standards were seldom mandatoiy because few states adopted them. The U.S. Department of Transportation (DOT), which now has responsi-bihty for pipe-line regulation, issued Title 49, Part 192—Transportation of Natural Gas and Other Gas by Pipeline Minimum Safety Standards, and Part 195—Transportation of Liquids by Pipehne. These contain considerable material from B31.4 and B31.8. They allow generally higher stresses than the ASME Pressure Vessel Code would allow for steels of comparable strength. The enforcement of their regulations is presently left to the states and is therefore somewhat uncertain. 

When raw natural gas comes to the surface it is often saturated with heavier hquids. Should the gas be cooled, in an undersea-pipeline for instance, then some of the heavier components condense to form a slug of liquid in the pipehne. These liquids are removed in a series of large pipes known as a slug catcher - Figure 3.1. 

Small gas utilities with single gate stations will distribute gas as received from the pipeline. The quality of pipehne gas is not constant. Since most gas contracts are based on MMBTU rather than MCF, the pipeline has httle incentive to sell gas stable in BTU. All he must do is stay within contract BTU limits. The pipeline may have little control over the gas quality. In today s market, he may only be the transporter where the user has purchased gas from a producer on the spot market . The demand for gas components will also determine the degree of stripping by the processor or producer who knows what quality of gas will come from a storage field. There are many reasons that the quality of pipeline gas is not stable. A typical span of pipehne BTU over a year might be 1000 -1066 BTU on a 30" mercury column 60T and diy base. 

A relevant restriction to be fulfilled for operating pipeUnes is the flow balance. I.e., the input flow equals the output flow implying constant physical conditions (such as pressure) for all pipeline segments. For instance, assume a serially operated multi-access pipehne where N is the set of access points consisting of destination points and M " feeding locations such that = 0 and JM " = N. The flow rate p is measured... 

The flrst point is a reasonable assumption provided there is a disjunctive categorization of locations into material (net) providers and (net) consumers such that there is one unique flow direction within the pipeline, i.e. Xj > 0 or X/ < 0 for all locations j. I.e. if the pipehne is serially operated, the total safety stock has to be distributed among the provider locations. Another situation occurs for cyclic pipehnes. Here, the material flow is unidirectional, but each location can act as consumer or provider as long as the total flow is balanced. The safety stock can be distributed among all participants along the pipehne as long as all participants can feed surplus material from stock to starving partners. 

Albeit the problem structure for branching pipehnes is generally similar to a pipehne structure with multiple depots located along one main pipeline, it comphcates the mathematical formulation by forcing to track batches along the pipeline branches which equals the modelling of additional pipelines. In the follow-up paper (MirHas-... 

Ship transportation is one of the most attractive transport modes for raw chemical procurement in chemical industry. Raw materials and basic chemicals are required constantly and in huge quantities to supply continuously operating chemical production plants. The ideal transport mode is the pipeline transport. However, pipehnes dedicated for basic and raw chemicals are seldom available due to large distances to bridge, high investment costs, and the inflexibility of sourcing. In most cases, raw and basic chemicals are transported by ships if a sea or river port is available. 

As shown in Fig. 15.6, external DC current is supplied from a power source such as a rectifier. The external DC current is used to cathodicaUy polarize the pipeHne. Impressed Current System (ICS) can be used to protect bare and poorly coated pipeHnes because of high current capacity. The anodes are made of durable materials that resist wear or dissolution. Iron with 14% silicon, carbon, and graphite are some commonly used anodes for pipeline protection [17,18]. All impressed current CPs require routine maintenance because they involve a power supply and more electrical connections than sacrificial systems. 

Measuring the pipehne potential with reference to a nonpolarized reference electrode (e.g., CU/CUSO4) is one of the most commordy used methods for potential survey (PS) of the pipeline. This method is based on the potential criteria Usted in the previous section. Presently, battery operated, inexpensive, light (50 MO or higher) internal resistance voltmeters with a resolution of 1 mV are widely available. Microprocessor digital recorders caUed data loggers are more frequendy used for monitoring pipehne potential. 

C. Ringas, J.M. Leeds, P. Osthuizen, The appKcation of DC voltage-gradient technology to accurately determine buried pipehne rehabilitation requirements, in Pipeline Risk Assessment, Rehabilitation and Repair Conference, Houston, Texas, September 12-15, 1994, organized by Pipeline Industry and Pipes Pipelines International. 

The results of case indicate that 8 pipehne should be replaced partially or wholly because of its high risk level and severe pipehne corrosion 6 pipehne should be provided with regular inspection with an interval of about one and a half years, and its anti-corrosion wall should be thickened The rest six pipelines are at a low risk level, thus their test interval can be extended with regular inspection and maintenance. 

The most interesting example of the use of Sprut-9 took place in Kazakhstan on the Mangyshlak oil field. Very viscous oil is produced on this field, and it has to be preheated for pipehning. Part of a pipeline passed along the bottom of a saline lake, and the water produced rapid breakdown of the thermal insulation and antirust coating of the pipe, sharply decreasing the pipe s transfer capacity. A group of divers... 

The only alternative to the adhesive method for underwater pipelines repair is replacement. The cost of construction of underwater mains crossing large rivers amounts to 10-50 milhon dollars. The cost of repair by the adhesive method is 10-50 thousand dollars. These data were obtained for repair of pipehne junctions through the Volga, Yenisei, and Moscow rivers, and for operations in the Okhotsk Sea, in swamps near the river Goryn (Belarus), in Bulgaria (Stevis Corporation), and from other projects. 

The motors mounted on the front wheel of ADT are close to the cooling tank which is connected with the diesel engine water tank. Fixed the diameter of pipeline to the motor 2, the flow distribution of these two motors can be optimized by increasing the diameter of pipeline to the motor 1. The Flow distributed to the driving motor 1 and 2 can be seen in Figure 13. The x-axis in Figure 13 represents the diameter difference of the pipehnes which connected to the motor 1 and 2 respectively. 

The diameter of pipeline to the driving motor 3 is optimized as d3=32mm when the difference of the water supply volume between the motor 1 and motor 3 reaches the minimum. The flow rate of cooling pipehne and the motor temperature can be adjusted by varying the diameter of the pipe. The larger the pipeline diameter, the flow volume distributed to cooling... 

Mine dewatering rising mains from mid-shaft to surface—2 x 200DN pipelines Compressed air supply line from surface to underground— 1 x 200DN pipeline Raw water/ Fire water dropper for the mine to mid-shaft and shaft bottom—1 x 150 DN pipehne... 

The depot receives fuels via three pipelines from refineries located in different parts of Britain. At the time of the incident an aggregate total of 189,000 British tons (212,000 US tons) of aviation fuel, diesel, gasoline, and 15,000 British tons (16,800 US tons) of heating oil in the tankage were stored in the Buncefield storage tanks. Pipehnes transport fuel in batches and various grades of fuel were separated into dedicated tanks according to fuel type [ 1 ]. 

The task of purging pipehnes for maintenance is almost second-nature to well-experienced operators in this imit. Typically, pipeline clearing is routine and is uneventful. This time, however, the utihty dry air system was also being utiUzed as a source for instrument air in the operating area. Hence, this corrosive material was able to backflow throughout the instrument air system into monitoring and control systems. The backflow created expensive instrument damages. 

Pipeline Dividing up an instruction ejfficution into overlapping steps that can be executed simultaneously with other instructions, each step represents a different pipehne stage. 

The EDCA process incorporates standard techniques for compiling historical information, pipehne and soil surveys, external pipeline inspections, and data einalysis. The procedure includes no new measurement techniques, but it does allow for the future addition of such techniques. Some rules ind information about EDCA arc present in NACE RP0502—Pipeline External Corrosion Direct Assessment Methodology. 

For natural gas, transportation begins at the point where the gas leaves the facility after production separation and dehydration at the gas plant. Natural gas pipelines between the gas well and the gas plant are considered to be part of the production process, rather than transportation, and wastes that are rmiquely associated with production that are generated along such a pipehne are exempt. 

---