Protection systems testing

The author is sure that the readers will find ample opportunity to learn from his experience and apply this information to their field of activities. The book aims to provide a bridge between the concept and the application. With this book by his or her side, an engineer should be able to apply better, design better and select better equipment for system needs and ambient conditions. It should prove to be a handy reference to all those in the field of design and application, protection and testing, production, project engineering, project implementation or maintenance, in addition to the sales and purchase of these products. 

Risk sensitivity results are also very useful in identifying key elements in your existing loss prevention program. For example, suppose your fire protection system was assumed to have a very low probability of failure because you test it weekly. Fire protection failures may not show up as an important contributor to your total risk (because failure is so unlikely), but your total risk estimate may be extremely sensitive to any change in the probability of fire protection failures. Flence you should not divert resources away from testing the fire protection system unless the alternate use of funds will decrease risk more than the reduced testing will increase risk. 

Reference electrodes at the test points may only be needed part of the time, depending on the mode of operation of the protective systems (e.g., for monitoring or for permanent control of potential-controlled protection current equipment). Potentiostatic control is always preferred to galvanostatic systems where operational parameters are changing. 

Ensure that the fire protection systems in the major equipim-m l1c< in.. u rooms are adequate and are periodically tested... 

The compressor was fitted with a protective system that should have made it impossible to start the machine with the barring gear engaged. But the protective system was out of order. It was not tested regularly. 

The test took more than an hour. The protective system was therefore out of action for about 5% of the time. There was a chance of 1 in 20 that it would not prevent an explosion because it was being tested. It was, in fact, under test when the oxygen content rose. 

Table 6.2 presents an overview of surface-emissive powers measured in the British Gas tests, as back-calculated from radiometer readings. Peak values of surface-emissive powers were approximately 100 kW/m higher than these average values, but only for a short duration. Other large-scale tests include those conducted to investigate the performance of fire-protection systems for LPG tanks. 

Tests carried out on protection systems comprise factory tests, on-site commissioning tests and maintenance checks. Those made on individual relays will demonstrate the compliance of the equipment with specification and the verification of its operation under simulated conditions, while tests carried out on-site prior to the equipment being put into service ensure that the full protection scheme and associated equipment operate correctly. These on-site tests must be comprehensive and should include ... 

Estimate of current required The surface area of the structure is calculated and the current density required for the particular environment is selected (Table 10.26). In the case of an existing structure the condition of the coating may be unknown and the application of a temporary cathodic-protection system may be necessary to determine the amount of current required for protection, as established by the potential. Such a test to determine the... 

High-voltage coating-testing equipment When cathodic protection is applied to a structure which has a protective coating, the current required is proportional to the bare metal area on the structure. Thus whenever a protective coating is applied it should be of good quality, with very few failures or pin holes in it, so that the cathodic-protection system may be economic. 

In the past, copper was believed to be toxic to most microbiological species. Although this may be true in a test tube under laboratory conditions, it is not generally true in the real world. In this real world, microbial communities excrete slime layers which tend to sequester the copper ions and prevent their contact with the actual microbial cells, Aus preventing the copper from killing the microbes. Many cases of MIC in copper and copper alloys have been documented, especially of heat-exchange tubes, potable water, and fire protection system piping. 

Overall effectiveness of protective systems and emergency controls. Protective systems, such as alarms, shutdown systems, and emergency controls, are often the keys to incident prevention and timely operator response. Protective systems that are properly designed, tested, and well maintained can reduce the frequency of event occurrence. Conversely, systems that are not tested and maintained may result in a high frequency of event occurrence. 

In a Japanese plasma wind tunnel, SPA specimens were tested up to 3.8 MW/m2 at 0.7 bar aerodynamic pressure (Fig. 12). After a test duration of 60 s, no obvious damage was visible. The surface temperature of about 2600°C was reduced to 100°C within 20 min. Further analysis showed a maximum charred depth of the ablator of 15 mm. The carbonization process did not change the geometric dimensions, the new heat protection system can be considered absolutely stable to deformation. The carbonized layer still has a noticeable pressure resistance and transfers the load applied by the dynamic pressure to the structure. 

For a liquid thermal expansion relief device that protects only a blocked-in portion of a piping system, the set pressure shall not exceed the lesser of the system test pressure or 120% of design pressure. 

In addition, where appropriate, the lines of defense should be tested and practiced on a regular basis to ensure the reliability of the systems. These tests should be documented as part of the facility records. Unreliability of protection systems must not be allowed to be a cause of an accident or allow an accident to result in more severe consequences. 

Who has ownership of hre protection systems How are they inspected, tested, and maintained Whal are the impairment procedures ... 

The use of cost-benefit analysis plays an important role in the decision-making process for fire protection systems. A cost-benefit analysis sums the expected benefits and is divided by the sum of the expected costs. A challenge often lies in determining what "expected" means and estimating the value of money over the time period the fire protection is in use. In fire protection, the expected benefits can be defined as the difference between the cost of a loss without protection and the cost of a loss with protection. The exported costs include the initial costs of the fire protection as well as any annual testing and maintenance costs. The likelihood of an incident is factored in to obtain residual risk. This residual risk is compared to the benefit to determine what benefit is available each year versus the annualized cost. 

The reliability and availability performance requirements of safety systems and especially fire protection systems should be considered in the design. Fire protection systems are not used on a regular basis, but must work when required. It is also important that the design of the fire protection system facilitate a testing and maintenance program for achieving these goals. 

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