Pipehnes systems

The wet gas pipehne system continuously exhibits the need for probes. In wet gas systems, liquid carryover in instrument supplies, valve operations, and chemical injectors is a corrtinual problem. 

The mean values and the standard deviations of the pipehne system unconditional lifetimes in the (12) lehabdity state subsets, respectively are... 

Through the Surface Pipeline Security Branch within the TSA. The Security Branch is designed to enhance the security preparedness of the nation s hazardous liquid and natural gas pipehne systems. 

There are limitations to what CP can do. The CP current must be able to flow through a conducting environment onto the metallic surface being protected. Using the same pipeline example, a basic CP installation such as shown in Fig. 13.10 would protect only those external surfaces of the pipe that are in contact with the conducting environment. The internal surfaces of the pipe would receive no protection. This would remain true even if the pip>e contained a conductive material since the metallic pipe would intercept the protective current and simply carry it back to its source. Similarly, any portions of the pipehne system in air (such as aboveground... 

When the system which was to be linked to the autosampler system was purchased, it was found that the conductivity cell was excessively large and primarily designed to be fitted to a A" pipehne for analytical purposes this was clearly too large. However, the pH cell provided an Ingold standard electrode system with dimensions which allowed it to be placed within the conductivity sensor, as shown in Fig. 7.21. It is therefore possible to configure a flow cell in which the conductivity sensor houses the pH electrode. The latter also serves to take up most of the cell volume so that the wash-out requirements are not too excessive. The cell is filled by taking a sample from the autosampler with pump 1 hquid fills the cell and overflows via the weir arrangement and the top of the cell. 

Relvas, S., Matos, H., Barbosa-Povoa, A., Fialho, J., and Pinheiro, A. Pipehne scheduhng and inventory management of a multiproduct distribution oil system. Industrial engineering chemistry research, 45(23) 7841-7855, 2006. 

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. 

In 2005, the natural gas distribution grid in Brazil was about 12.9 thousand kilometers long, and is concentrated in the states of the Southeast, especially in Rio de laneho and Sao Paulo, which have about 72% of total distribution in the network (BEN, 2008). The northeast region has 1.6 thousand kilometers of pipehne distributing natural gas (12% of the national distribution system). 

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. 

Watch for signals from leak detection systems. For H2S-containing systems that focus directly on the measurement of H2S, pressure changes can indicate a leak, while temperature changes can be a sign of a loss of containment and potential fire. Signals from these detection systems can start a well shut-in or isolation of sections of pipehne, so it is important to know the features of the system you are working with. 

Bin System. The bin system is primarily of historical interest. In this system the coal is processed at a location apart from the furnace, and the end product is pneumatically conveyed to cyclone collectors, which recover the fines and clean the moisture-laden air before returning it to the atmosphere. The pulverized coal is discharged into storage bins and later conveyed by pneumatic transport through pipehnes to utihzation bins and from there to the furnace. 

Figure 8.16 shows an equivalent electrical circuit that simulates the pipeline cathodic protection depicted in Figure 8.9. Both pipeline and sacrificial anode (galvanic anode or inert anode) are buried in the soil of uniform resistivity. The pipehne is connected to the negative terminal and the anode to the positive terminal of an external power source (battery). The arrows in Figure 8.16 indicates the direction of the ciurent flow from the anode to the pipehne. The electron flow is also toward the pipehne to support local cathodic reactions and the protechve current (Ip) flows from the pipehne to the power supply. The soil becomes the electrolyte for complehng the protective electrochemical system or cathodic protechon circmt [24].

Brito, A.J., de Ahneida, A.T. 2009. Multi-attribute risk assessment for risk ranking of natural gas pipehnes. ReUabUity Engineering System Safety, 94(2), 187-198.doi 10.1016/j.ress.2008.02.014. 

There essentially two major valve types one with a hnear characteristic and one with an exponential characteristic. One should keep in mind, however, that a hnear valve may not behave linearly when installed in a pipeline circuit. The flow rate is not determined solely by the valve characteristics, but also depends on the resistanee of the pipehne and the pump characteristics. It is therefore essential to evaluate the entire eincuitiy in which the valve is installed. Figure 31.14 shows how the pump pressure varies with the flow through the system. At F = 0 the pump head is APp o- The maximrrm flow without valve is F. The range of the valve covers only a part of the total possible range and varies from F ose. to F... 

Thermal expansion and contraction are key items of concern in the design of a thermoplastic piping system. Design parameters should be developed and incorporated into the installation specifications. Thermoplastic piping materials have a higher coefficient of expansion than some other common pipehne materials, however, the forces generated by thermal stresses are much lower because the modulus of elasticity is lower and it is capable of stress relaxation. 

U.S. Department of Transportation, Office of Pipehne Safety. 1995. Exemplary Practices and Success Stories In One-CaU Systems. Washington, DC. May. 

Useful observations have also been obtained based on a comprehensive assessment of the Joule-Thomson cooling effect predicted for CO2 pipehne packing during the initial system startup. The assessment results from a series of dynamic simulations built upon different operating scenarios. 

A typical CFRP liner system consists of primers, thickened resins, resins, reinforcing fabric, and topcoat. The most effective resin systems for long-term civil infrastructure rehabilitation applications, such as rehabilitation of PCCP lines, are ambient-cure thermoset epoxy systems. In order to minimize environmental hazards present inside the pipehne during application of the materials, epoxy systems that are made of 100% solids and are VOC compliant are utilized. 

Alexander, C., Francini, B., State of the art assessment of composite systems used to repair transmission pipehnes. Stress Engineering Services, Inc. and Kiefiier Associates, Inc., Proceedings of IPC2006,6th International Pipeline Conference, IPC2006—10484, Calgary, Alberta, Canada, September 25—29, 2006. 

ASME PCC-2 Article 4.1, Non-metaUic Composite Repair System for Pipehnes and Pipework High Risk Applications, 2006. 

DueU, J.M., Wilson, J.M., Kessler, M.R., 2008. Analysis of a carbon composite overwrap pipehne repair system. International Journal of Pressure Vessels and Piping 85, 782—788. http //dx.doi.Org/10.1016/j.ijpvp.2008.08.001. 

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