Lloyd’s Register's Rules and Regulations for the Classification of Offshore Units (Rules for Offshore Unit) require a blast / explosion load to be defined by the owners / designers.
This is then used as a design basis for the offshore unit. It is usually not feasible to design for a worst case scenario, and as credible scenarios cannot be uniquely defined, the Rules for Offshore Units allow for the dimensioning of explosion loads to be based on probabilistic risk assessment techniques.
Originally published in 2013 the Guidance Note has already been extensively used in explosion risk studies around the world to document that a selected design is acceptable in terms of risk level, and the risk level associated to a given design can be identified.
These Guidance Notes provide a methodology to establish risk based explosion loads based on a probabilistic approach. The methodology is applicable to any offshore unit where gas explosion hazards are relevant, but includes special guidelines on how to include and handle leak scenarios specific to Liquefied Natural Gas (LNG) plants due to flashing of cryogenic liquids like LNG and Liquefied Petroleum Gas (LPG) when released to atmosphere.
Click here to download the Guidance Notes for Calculation of Probabilistic Explosion Loads.