Design altering

A redesign solution of the toleranee staek is shown in Figure 3.11. It involves a small design alteration (eireled) whieh eliminates the plastie bobbin from the toleranee staek by maehining a shoulder on the inside of the solenoid body, up to whieh the pole pieee is preeisely loeated. Also, seeondary maehining proeesses are... 

The required lead time for ordering equipment has to take into account all the above factors. Too often the time required for possible design alteration, which may be found necessary, is overlooked. In order to min-... 

In this study detailed fault trees with probability and failure rate calculations were generated for the events (1) Fatality due to Explosion, Fire, Toxic Release or Asphyxiation at the Process Development Unit (PDU) Coal Gasification Process and (2) Loss of Availability of the PDU. The fault trees for the PDU were synthesized by Design Sciences, Inc., and then subjected to multiple reviews by Combustion Engineering. The steps involved in hazard identification and evaluation, fault tree generation, probability assessment, and design alteration are presented in the main body of this report. The fault trees, cut sets, failure rate data and unavailability calculations are included as attachments to this report. Although both safety and reliability trees have been constructed for the PDU, the verification and analysis of these trees were not completed as a result of the curtailment of the demonstration plant project. Certain items not completed for the PDU risk and reliability assessment are listed. 

Design, alteration, modification, construction, maintenance, and testing of fire protection systems and equipment... 

Reqnirements, and thns designs, altered dnring development often have a hngely damaging impact on system qnality. 

SOP for periodic review by Security Manager and escalation to senior management as appropriate Recommend design altered to only allow one active terminal per user at a time... 

In general, side reactions are more problematic at higher cathode current densities (i.e. at more negative cathode potentials) and they may be minimised by appropriate cell design, alteration of the solution chemistry (where possible) and control of the electrolysis conditions. 

Reduce risk through design alteration If adopting an alternative design is not feasible, consider design changes that reduce the severity and/or the probability of the mishap potential caused by the hazard(s). 

Reduce mishap risk through design alteration. 

If unable to eliminate or adequately mitigate the risk of a hazard through a design alteration, reduce the risk using an ESP that actively interrupts the mishap sequence. 

Design alterations - involving chemistry, material, or equipment modifications. 

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