Piping, processing facilities

Gas processing facilities generally work best at between 10 and 100 bar. At low pressure, vessels have to be large to operate effectively, whereas at higher pressures facilities can be smaller but vessel walls and piping systems must be thicker. Optimum recovery of heavy hydrocarbons is achieved between 20 bar and 40 bar. Long distance pipeline pressures may reach 150 bar and reinjection pressure can be as high as 700 bar. The gas process line will reflect gas quality and pressure as well as delivery specifications. 

If produced gas contains water vapour it may have to be dried (dehydrated). Water condensation in the process facilities can lead to hydrate formation and may cause corrosion (pipelines are particularly vulnerable) in the presence of carbon dioxide and hydrogen sulphide. Hydrates are formed by physical bonding between water and the lighter components in natural gas. They can plug pipes and process equipment. Charts such as the one below are available to predict when hydrate formation may become a problem. 

Many materials are conveyed within a process facility by means of pumping and flow in a circular pipe. From a conceptual standpoint, such a flow offers an excellent opportunity for rheological measurement. In pipe flow, the velocity profile for a fluid that shows shear thinning behavior deviates dramatically from that found for a Newtonian fluid, which is characterized by a single shear viscosity. This is easily illustrated for a power-law fluid, which is a simple model for shear thinning [1]. The relationship between the shear stress, a, and the shear rate, y, of such a fluid is characterized by two parameters, a power-law exponent, n, and a constant, m, through... 

Silver is usually found in extremely low concentrations in natural waters because of its low crustal abundance and low mobility in water (USEPA 1980). One of the highest silver concentrations recorded in freshwater (38 pg/L) occurred in the Colorado River at Loma, Colorado, downstream of an abandoned gold-copper-silver mine, an oil shale extraction plant, a gasoline and coke refinery, and a uranium processing facility (USEPA 1980). The maximum recorded value of silver in tapwater in the United States was 26 pg/L — significantly higher than finished water from the treatment plant (maximum of 5.0 pg/L) — because of the use of tin-silver solders for joining copper pipes in the home, office, or factory (USEPA 1980). 

Process Facilities 15 Area electrical classification 16 Accessibility for mechanical integrity (sampling, maintenance, repairs) 17 Protection of piping and vessels from vehicles and forklifts 18 Protection of small-bore lines, fittings from external impact, personnel 19 Routing of process piping, critical controls cable trays, critical utilities 20 Vent, drain, and relief valve discharge locations... 

Localized failures of pressurized piping, process pumps, vessels or other parts of the process under pressure will cause a "torch" or "jet" fire. These fires may project flames in any direction, for a considerable distance, depending on the contained pressures and volumes of the source. Any facility that retains large amounts of high pressure liquids or gases can produce jet for extended periods if adequate isolation and depressurization capability is unavailable. The worst offenders in these cases are wellheads, high pressure gas pipelines and storage facilities. 

Piping in processing facilities may be routed and supported in several ways the most common are ... 

Processing facilities have experienced several serious pipe trench fires. Contributing to the size of the fires were inadequate or plugged drains, lack of isolation valves, pipelines on the ground, or inadequate fire stops along the length of the trenches. Pipe trench fires can result in significant business interruption. 

Outside battery limit (OSBL) defines the work and responsibilities outside the battery limit. The OSBL includes auxiliaries required for the chemical process unit, including tank storage for feedstock and refined products, waste treatment, cooling towers, flares, and utilities that are not included in the battery limit but are required for the unit. Also included are the pipeways, racks, and sleepers, which are used to convey all of the utility s interconnecting process piping to and from the processing facility... 

Piping Instrumentation Drawings (P IDs), that are "as-built" verified for the existing hydrocarbon processing facilities. ... 

Processing Facilities. The phenolic-foam-producing process is simUar to that used with rigid polyurethane foams. Production of composite sandwich panels, board-type products, pipe covers, are possible. 

Generally, the concentration of antimony in the air varies from 1 x 10-6 mg/m3 to 170 x 10-6 mg/m3 and can be as high as 1000 x 10-6 mg/m3 near antimony processing facilities (33). Because of the stability of antimony in aqueous systems, the concentration of dissolved antimony in rivers is very small (about 5 ppb antimony). Also, despite the fact that antimony is in the solder used in water pipes, it does not appear to dissolve in the drinking water. 

The first commercial Twister installation was implemented by Pefronas and Sarawak Shell Berhad (SSB) on the Bll offshore gas processing facility in Decanber2003. The unit dehydrates bOOMMcfd of non-associated sour gas fed to the onshore Malaysian LNG plant at Bintulu, to control pipe corrosion, and has at the time of writing being in continuous operation since start-up with over 99% availability. Table 9.1 compares capital expenditure for the Twister and other options for offshore gas development... 

Chemical processing facilities usually contain many pressurized pipelines. These lines may be at elevated or cryogenic temperatures and may convey flammable, toxic, reactive, or corrosive fluids. Piping systems transporting such flvuds must be designed, installed, operated, and maintained properly to... 

The optimum piping arrangement in a tank form, as elsewhere in a process facility, is the most direct route between two points, allowing for normal line expan-.sion and stresses. Exhibit 15-40 illustrates piping between tanks and pumps. Anchor points, or places vdiere piping movement is restricted, mast be established..Tank nozzles are one such anchor point. The second anchor point may be the pump nozzle if line growth is permitted through the dike, or it may be... 

The modem chemical or petroleum processing facility is characterized hy its complex piping layout. A portion of the complexity is reflected in the presence of various types of fittings (some examples are shown in Figure 3-4). 

Process facilities susceptible to earthquakes should be provided with suitable restraints for fire protection systems. The extent of these restraints are normally dictated by local ordinances and primarily concern the bracing of pipework and adequate securing of firewater pump base plates and controller panels for earthquake forces. Pump houses should be adequately constructed and braced so they will not collapse onto the firewater pump or distribution piping. 

When possible, firewater mains should be arranged in loops around process facility and tank farms. Shutoff valves should be located to allow isolation of system segments for maintenance while stiU providing water for all facilities. The minimum water rate with a section of pipe out of service should be at least 60% of the design rate at design pressure for that area. A firewater header should be provided in each process facility area to serve hose stations. 

Speckle shearing interferometry, or shearography, is a full field optical inspection teclmique that may be used for the nondestructive detection of surface and, sometimes, subsurface defects. Whilst being more sensitive in the detection of surface defects, it may also be considered for pipe inspection and the monitoring of internal conoslon. In contrast, laser ultrasound and other forms of ultrasound, are point by point measurement techniques, so that scanning facilities and significant data processing is required before information on local defects is extracted from any examination of extensive areas [1 - 3]. 

Steam-Generating Facilities These form the second largest investment item for chemical-plant auxiliaiy equipment. Variations in capacity, location indoors or outdoors, the type of fuel used, pressure and temperature levels, and the type of process served have an important effect on actual cost as well as on cost relative to other auxiliaiy items. Package boiler instaUations can be purchased as shop-built units which are assembled, piped, and wired ready to be erected on the owner s foundations. They are available in units up to about 136,000 kg/h (300,000 Ib/h), although units larger than about 45,360... 

---