I am requried to attend Hazop studies as process engg.
(Q-1 )Normally it is said that if pipe is adequately design for pressure protection , then leak or spill is not considered.
in this case, how and where to cover consequences of any possible leak if system is handling flammable or toxic gases ?
(Q-2) Some consultant consider F&G and leak as one deviation and then describe consequence and try to locate mitigations available as part of design . However, i am of the opinion that there should be a cause for any thing. Flammable gas leak is a consequence and not a cause. if process is adquetly designed for pressure with corrosion and other mechanical integrity considerations, then there is no cause for leak.
is a right practice to start hazop discussion like deviations as leak or spill. ? ( my key point is that when we design system properly applying all applicable code and standards, example over pressure protection etc, and later if we consider leak , then we do not have other points to consider for taking credits. we may land up with extra precautions which are not required. exmaple one of the consultant was seen providing low pressure alarm and trip to alert operator and isolation system.)
(Q-3) To differnt type of check valve can be taken as credit during Hazop ?