Worst case operating conditions

The worst case operating condition is at the high input voltage. 

For reaction systems without solvents, the time at the test temperature is important. In these cases, the elected period of time and temperature should be based on the worst case operating conditions. 

The plant was reassembled in its normal 12-kW configuration with cathode spacers fitted. To provide a worst-case operating condition, the back pressure on the catholyte system was removed so that the spacer was the only mechanism that kept the membrane from contacting the cathode. The plant was run for 24 hours under these conditions, and the cell was dismantled to inspect the membranes. There were no signs of damage to the membrane surfaces and no signs of silver deposits. 

At the initial stages in design, we identified only the general hazards—for example, instabihty of the robot base and the related system design constraint that the mobile base must not be capable of falling over under worst-case operational conditions. As design decisions are proposed and analyzed, they will lead to additional refinements in the hazards and the design constraints. 

Once the max delay requirements imposed due to the setup constraints for the sequential cells have been met, DC can be used to fix the minimum path delay requirements. Since the path delays are the maximum in the worst case timing analysis or worst case operating conditions, max delay requirements must be met in the worst case operating conditions. 

Clock Spring design required a safety factor of 2 based on a maximum anticipated load of 10 ksi (69 MPa). The composite was designed to withstand 20 ksi (138 MPa) loads at 50 years of exposure to worst case operating conditions. Based on this equation the Clock Spring 20 ksi (138 MPa) design life is 67 years. This equation shows the minimum new (t= 1) tensile strength of the composite should exceed 42 ksi (290 MPa) (GRI, 1998). 

Challenge Tests/Worst Case A condition or set of conditions encompassing upper and lower processing limits and circumstances, within standard operating procedures, that pose the greatest chance of process or product failure when compared with ideal conditions. 

At the Biyan site the main line flow constrictor was installed flush against an isolation valve and a 90° elbow. This was done to establish worst case test conditions. It was expected on theoretical grounds that the operation of the flow separator would be insensitive to upstream flow conditioning of the gas. Test data taken to date has proven this to be the case. 

Objective data for exemption from requirement for initiai monitoring, (i) For purposes of this section, objective data are information demonstrating that a particular product or material containing cadmium or a specific process, operation, or activity involving cadmium cannot release dust or fumes in concentrations at or above the action level even under the worst-case release conditions. Objective data can be obtained from an industry-wide study or from laboratory product test results from manufacturers of cadmium-containing products or materials. The data the employer uses from an industry-wide survey must be obtained under workplace conditions closely resembling the processes, types of material, control methods, work practices and environmental conditions in the employer s current operations. 

Simulation Models. Simulation models are extended versions of functional models.They contain all the functional information as well as detailed information about path delays through a part and rise and faU times. They are used to ensure that worst-case timing conditions result in a properly operating design. 

Systems are designed for worst-case design conditions and operate most of the time at less than design conditions. 

When a molten plastic is forced through a die it is found that under certain conditions there will be defects in the extrudate. In the worst case this will take the form of gross distortion of the extrudate but it can be as slight as a dullness of the surface. In most cases flow defects are to be avoided since they affect the quality of the output and the efficiency of the processing operation. However, in some cases if the flow anomaly can be controlled and reproduced, it can be used to advantage - for example, in the production of sheets with matt surface finish. Flow defects result from a combination of melt flow properties, die design and processing conditions but the exact causes and mechanisms are not completely understood. The two most common defects are... 

Operational qualification involves performing a series of tests to check that all elements of the system are functional across the specified operating range. This usually involves performing challenges at the worst case extreme operating conditions. The process should allow confirmation of final operation, maintenance and calibration procedures. 

Under certain conditions, a BIF owner/operator may obtain an exemption from the DRE requirements when burning low-risk waste. Waste can be shown to be low risk if, under a reasonable, worst-case scenario, emissions of organics, and metals do not exceed acceptable levels. 

Worst-case analysis based on the DSC data, namely, the test with the lowest onset temperature, resulted in a graph showing the relationship between initial temperature and time-to-maximum rate under adiabatic conditions. For an initial temperature of 170°C, it would take 2 hours to reach the maximum rate. Venting simulation tests were undertaken on a larger scale to detect safe venting requirements for the separator and for the MNB hold tank. Several vent sizes were tested. It was found that a 10-cm rupture disc with a burst pressure 1 bar above the operating pressure was adequate. 

Inherently safe maintenance of a system in a non-hazardous state after the occurrence of any credible worst case deviations from normal operating conditions. 

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