Pipe rig tests

Pipe rig tests in the Netherlands In The Netherlands in the mid 1980s a pipe rig was developed and used at several pumping stations to measure lead and copper concentrations in the drinking water. The rig consists of three pipes through which water is flowed continuously except when sampling. The flow rate is about 0.05 m/s. The metal concentration in the drinking water is measured after 24-hour stagnation. 

For copper, the rig tests are applied at pumping stations where the water has a high copper solubility. For lead, the rigs are plaeed at the majority of the pumping stations that deliver water to areas with lead pipes. The results from the pipe rig test show a good correlation with metal concentrations at the tap. The Netherlands government has accepted the pipe rig test for compliance monitoring. 

Experimental procedure The experimental procedure for pipe rig tests is related to the German standard DIN 50931, Part 1 (see above). 

The variety of situations that can occur in authentic plumbing systems cannot be fully represented by any single simple sit-and-soak or pipe-rig test procedure. 

The pipe-rig test procedme, carried out in this research can provide the information necessary for the evaluation of potential migration from metallic materials when in contact with potable water. 

A pipe-rig test procedure can simulate an authentic situation and so give a direct quantitative assessment of the potential to contaminate by metals in relation to the particular operating conditions and test water used. Consequently pipe rigs are necessary for the evaluation of potential migrations fi om metallic materials. 

An example of a basic environmental test bed would be a temperature controlled tank of a liquid, perhaps sea water. This basic structure is applicable to a considerable range of products and can involve acceleration by using more severe conditions than in service. In one use of such a rig, the insulation on oil riser pipes is tested by circulating hot oil through the pipe whilst it is immersed in the tank. 

RDT or 30MS sampling are appropriate for identifying areas that require priority action to reduce lead levels. Previous studies show that the lead pipe test (pipe rigs at the treatment facility) can also be suitable for this purpose. 

Until now simplified methods have been available to monitor metal release by metallic pipe materials. In the United Kingdom a sit-and-soak test is available to determine the metal release from drinking water materials. In The Netherlands, copper and lead pipes in combination with water quality are tested in pipe rigs, and in Germany a protocol for testing pipe materials is available (see below). 

Sit-and-soak tests have been earned out with BS 7766 standard test water and with laboratory tap waters (composition of waters given in Table 4.3). Pipe rig experiments have been carried out with laboratory tap waters, and four materials have been tested copper, brass (eopper with brass fittings for pipe rigs), galvanized steel, and stainless steel. 

Results with the laboratory pipe rig waters Because of the different water qualities, it was obviously not possible to study the reproducibility of the results from the tests that used the different laboratory waters being supplied to the respective pipe rigs. However, it was possible to make a few generalizations. 

Figure 4.4 Example of test device for pipe rig experiments...

Seismic structural integrity test rig has been constructed. Piping dynamic test for evaluation of ultimate strength of piping components are under preliminary examination. 

Slides Tungsten filaments, turbine blades, lead drain pipes and organ pipes, glaciers creep-testing rigs micrographs of creep cavities. 

The article hy Wilson and Flessner gives the dividing line as roughly 50 ft/s between slow flames that can be simply quenched and fast flames that must also be decelerated. Fast flames described in the article have speeds above 60 ft/s as opposed to turbulent flames, which are described as having speeds from 5 to 100 m/s in most venting systems. The test rig described in the article was composed of 6-inch diameter pipe. 

The deflagration flame arrester must he subjected to a series of at least 10 explosion (deflagration) tests in a rig with a pipe at least 5 feet (1.5 meters) long with various mixtures of propane in air and different test conditions to test the entire spectrum of possible deflagrations. Also, a series of 3 flashback tests, using a mixture of 4.2 volume percent of propane in air, must be conducted. 

Also the thermohydrolysis of the urea solution after the injection into the hot exhaust gas upstream of the SCR catalyst has been investigated at the diesel test rig. Urea solution was atomized about 3 m upstream of the SCR catalyst into the hot exhaust equivalent to a residence time in the pipe section of 0.1 s at 440°C. As expected for the thermolysis reaction, ammonia and isocyanic acid were found at the catalyst entrance at all temperatures (Figure 9.3). The 1 1 ratio of both components shows that only the thermolysis but not the hydrolysis is taking place in the gas phase. It can also be seen that the residence time of 0.1 s is not sufficient for the quantitative thermolysis of urea, as appreciable amounts of undecomposed urea were always found. The urea share even raises with lowering the flue gas temperature, although the residence time... 

However, the PVC powder was tested in a 52 mm internal diameter pipeline, 71 m in length, and found to exhibit unstable plugging in the vicinity of saltation or minimum pressure (i.e., prior to the fluidized dense-phase region). That is, dilute-phase transport was only possible on this test rig. Also, solids/gas loadings were quite low (e.g., max m 20). Note that the unstable plugging was accompanied by sudden increases in pressure and severe pipe vibrations. 

Oilfields in the North Sea provide some of the harshest environments for polymers, coupled with a requirement for reliability. Many environmental tests have therefore been performed to demonstrate the fitness-for-purpose of the materials and the products before they are put into service. Of recent examples [33-35], a complete test rig has been set up to test 250-300 mm diameter pipes, made of steel with a polypropylene jacket for thermal insulation and corrosion protection, with a design temperature of 140 °C, internal pressures of up to 50 MPa (500 bar) and a water depth of 350 m (external pressure 3.5 MPa or 35 bar). In the test rig the oil filled pipes are maintained at 140 °C in constantly renewed sea water at a pressure of 30 bar. Tests last for 3 years and after 2 years there have been no significant changes in melt flow index or mechanical properties. A separate programme was established for the selection of materials for the internal sheath of pipelines, whose purpose is to contain the oil and protect the main steel armour windings. Environmental ageing was performed first (immersion in oil, sea water and acid) and followed by mechanical tests as well as specialised tests (rapid gas decompression, methane permeability) related to the application. Creep was measured separately. 

Distributor performance should always be water-tested prior to startup. A similar recommendation was made by others (318a), with emphasis on critical services and large-dieuneter (> 8 ft) towers. This test can be performed in situ or at the manufacturer s shop. If not performed in situ, the piping supplying liquid to the distributor should be closely duplicated at the test rig. If maldistribution is apparent, it is best to seek the manufacturer s advice. The author is familiar with experiences where severe maldistribution problems could have been detected and rectified prior to startup if a water test had been performed. One experience has been reported (349) where a water test led to the solution of an absorber separation problem which resulted from maldistribution. 

Material tested Pipe material Internal diameter (mm) Fittings Rig volume (litres)... 

Figure 4.3 Design of test rigs, (a) Pipe materials (copper, galvanized steel, stainless steel) (b) copper pipe with brass fittings...

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