Experiment proof test

Many chemical processes require unusual vessel configurations. The heads of such vessels can have an infinite number of contours. One such contour is shown in Fig. 9. Ig. The design of these heads is very complicated and there are no simple methods of analysis. Experience, proof testing, and sophisticated analyses are generally used to detennine required thicknesses. 

At the present time, there is a fair understanding about the initiation of RPTs in various systems, but in some instances, particularly for metal-water accidents, the theory is poorly developed and untested in controlled laboratory experiments. The area of escalation of a small-scale RPT to a large, coherent explosion has been developed into a logical picture, but again proof tests on a large scale are not available. 

Data from crack velocity experiments are used to Improve the reliability of ceramic materials. It is particularly useful for the application of proof-testing to structural ceramics, because it leads to an estimate of lifetime under load after the proof test has been used to weed out mechanically defective components. For this purpose, the data in the low crack growth velocity range are of prime importance, because it is, by and large, slow... 

The frequency of proof tests should be consistent with applicable manufacturer s recommendations and good engineering practices, and more frequently, if determined to be necessary by prior operating experience. 

Initial startup testing procedures have been prepared and implemented to demonstrate that structures, systems, and components (SSCs) and processes will perform as intended. Initial testing includes, as appropriate, bench tests and proof tests prior to installation, mockup tests, pre-operational tests, post-maintenance tests, post-modification tests, and operational startup tests. Safety-related items are subject to the quality-assurance requirements of SNL/NM Research Reactor and Experimental Programs (RREP) Quality Assurance Program Plan (SNL 1998a), as implemented by the facility Project/Experiment Quality Plan (PEQP). Testing inciudes those initial tests mandated by applicable Technical Safety Requirement (TSR) surveiilance requirements (see Chapter 5.0, "Derivation of Technical Safety Requirements") and Operational Readiness Review (ORR) requirements (see DOE O 425.1 and DOE-STD-3006-93). 

All pressure equipment should be tested or inspected periodically. The interval between tests or inspections is determined by the severity of the usage the equipment has received. Corrosive or otherwise hazardous service requires more frequent tests and inspections. Inspection data should be stamped on or attached to the equipment. Pressure vessels may be subjected to nondestructive inspections such as visual inspection, penetrant inspection, acoustic emissions recording, and radiography. However, hydrostatic proof tests are necessary for final acceptance. These tests should be as infrequent as possible. They should be performed before the vessel is placed in initial service, every 10 years thereafter, after a significant repair or modification, and if the vessel experiences ovrapressure or overtemperature. 

Semlitsch, M. and Panic, B. (1994) 15 years of experience with test criteria for fracture-proof anchorage stems of artificial hip joints, in Technical Principles, Design and Safety of Joint Implants (eds G.H. Buchhorn and H.-G. Willert), Hogrefe Huber Publishers, pp. 23-36. 

Experience/training in the impact of proof testing on plant operation... 

The frequency of proof tests should include consideration of prior operating experience. 

Spencer et measured the turnover munber on Fe (111) face at ammonia concentration less than 1.5% of equilibrium value and at 2.0 MPa of total pressme and 748 K. These data were a very good proof-test for microkinetic models imder conditions far from equilibrium, and the models could be considered successful if the difference between the values predicted by models and obtained from experiments is in the range of about three times. 

Shibasaki et al. first reported a chiral barium catalyst prepared from BINOL monomethyl ether and barium alkoxide, which was a good catalyst for asymmetric direct-type aldol reactions (Table 1) [21]. In the presence of a barium catalyst, several aliphatic aldehydes were tested, and the desired cross aldol products were obtained in good yields with moderate to good enantioselectivities. For the substrate BnOC(CH3)2CHO, the best enantioselectivity was observed (Table 1, entry 6). Although there is no definitive experimented proof, the barium catalyst was assumed to be monometallic and could be stored for several months under argon atmosphere. 

We note that the use of diverse arguments and diverse evidence can help enhance confidence in a claim (discussed in the next section), but more work is needed on the integration of such evidence (like operational experience statistical testing, formal proof, and process evidence) to support specific claims (such as reliability). 

Until the second half of the twentieth century, the structure of a substance—a newly discovered natural product, for example—was determined using information obtained from chemical reactions. This information included the identification of functional groups by chemical tests, along with the results of experiments in which the substance was broken down into smaller, more readily identifiable fragments. Typical of this approach is the demonstration of the presence of a double bond in an alkene by catalytic hydrogenation and subsequent determination of its location by ozonolysis. After-considering all the available chemical evidence, the chemist proposed a candidate structure (or structures) consistent with the observations. Proof of structure was provided either by converting the substance to some already known compound or by an independent synthesis. 

Reactions were carried out in liquid phase in a well-stirred (1000 rpm) high-pressure reactor (Parr Instruments, 300 mL) at 30 bar and 150°C with 370 mg catalyst for two hours, unless otherwise specified. The feed consisted of the amine with slight excess of ketone at ketone/amine-group molar ratio of 1.6 while maintaining a reaction volume of about 150 mL. In a typical experiment, 576 mmol of aniline is mixed with 920 mmol of cyclohexanone and 370 mg of BS2 catalyst in the 300 mL reactor. The reactor is closed and then pressure-tested to 50 psi above operating pressure to ensure that the system is leak proof Once pressure-tested, the headspace is replaced... 

Although only a dozen known metal complexes were tested in this manner, proof of principle was demonstrated. The test revealed Wilkinson s catalyst to be the most active hydrosilylating agent, its use in this type of reaction being known. However, the study also led to the discovery that a palladacycle, [Pd (o-tolyl)2PC6H4 (OAc)]2, which is usually considered to be potent in Heck reactions, is also an excellent hydrosilylation catalyst.37,38 Control experiments showed that the relative order of catalyst activity is the same when conventional substrates are used in place of the dyes (8). 

In the first set of experiments, the water vessels had rusted bottoms. Of the 21 tests, 14 produced explosions, but no correlation of explosion probability could be deduced. It was reported that, in all tests, molten aluminum reached the bottom of the vessel. High-speed movies showed that the entire explosion sequence between the first visible disturbance in the system to a full-scale chemical reaction was very rapid (on the order of 600 /Ltsec). Note that the word chemical was used in the quote. Lemmon suggests that chemical reactions play a key role in the explosion phenomenon, particularly for violent incidents. The proof that chemical reactions are important stems from the finding that strong explosions produced light and, also, limited spectrographic data indicated local temperatures in excess of 3000 K. The emphasis on chemical reactions was not stressed in the work of other investigators. 

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