Operational Precautions

The validity of results can be maximized with the following precautions  

A more complete investigation of these components has been discussed previously. 

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The properties of selected cyanides of industrial importance are summarized in Table 5.35. Depending upon scale of operation, precautions for cyanides include ... 

When using a modern thermobalance which incorporates an electronic microbalance requiring small sample weights, the following operating precautions should be noted. 

Finally, HPLC is used for the analyses of explosives and in some forensic laboratories it is being introduced as a routine procedure. Chromatographic separation of explosives can be achieved by reversed-phase chromatography on alkyl-bonded silicas but a major problem has been in finding a technique capable of detecting nanogram quantities of materials. To date, the most sensitive method has been reductive electrochemical detection and provided fairly extensive operational precautions are taken (in particular the exclusion of oxygen), the required detection levels can be achieved. 

Oxide films formed on the steel surface prevent it from interaction with liquid lead. Since breakdown of oxide films is possible during operation, precautions must be taken for resuming and maintaining their thickness and density. 

Principles of safe design and operation. Precautions during plant modification. Special considerations with computer-controlled processes. Training of operators. 

Properties of, and hazards presented by, the chemicals used in the operations Precautions you will take to prevent the exposure of chemicals used in your operations to personnel and the environment. The precautions must include control technology, personal protective equipment, and measures to be taken if physical contact or airborne exposure occurs ... 

Safety dietates certain operating precautions for fuel-air eontrols. A defieiency of air can allow fuel to accumulate in the furnace, whieh upon ignition, may explode. Care must be taken, therefore, to ensure that the fuel rate never exceeds what is permissible for given conditions of air flow. Fuel and air flow both can be set from a master firing-rate control, but automatic selection is necessary to achieve this safety feature. A complete control system for control of fuel and air is shown in Fig. 9.8. ... 

An operating precaution that may seem rather obvious, but which nevertheless is frequently overlooked, is the prevention of sudden pressure surges. If the dehydration vessel is vented rapidly, fur example, very high, localized gas velocity may occur in the bed, causing bed motion, attrition, and even entrainment of the desiccant particles in the gas stream. Ballard (1978) recommends that the pressurization rate be limited to less than 50 psi per minute and that the depressurization rate be held below 30 psi per minute to avoid desiccant breakage and damage to the vessel internals. 

The operation of. short-cycle units has been described in detail by Ballard in several papers (1963, 196SA, B). Many of the operating precautions that he mentions are applicable to solid-bed adsorption plants generally. 

If medium and high risks are still remaining, the necessary operational precautions to reach an acceptable low remaining risk are identified. These may include adherence to certain job procedures, use of personal protective equipment, permit-to-work system, etc. Please note that high risks should only be remedied by operational procedures on an exceptional basis. 

Design measures, assumed operational precautions and the remaining risk are documented. 

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