In this master thesis, the effectiveness of a fire PSV has been investigated, when
offshore oil and gas process equipment is exposed to a small jet fire, large jet fire,
or a pool fire. According to API 521, care should be taken when a fire scenario is
affecting the unwetted part of a pressure vessel. Case studies are carried out, by
simulating fire scenarios, using a state-of-the-art simulation tool, VessFire, in order
to determine the effectiveness of a fire PSV. The case studies showed that a fire
PSV does not offer adequate protection, in fire scenarios where the unwetted part
of a pressure vessel is subjected to a fire. Alternatives to the use of a fire PSV,
such as blowdown and passive fire protection, are discussed. The applicability
of the stationary sizing method suggested by API 521, in fire case scenarios, are
investigated. API 521 suggests a dynamic model in order to better predict the
size of a fire PSV. A model is developed and compared with the stationary sizing
equations. Results show that the stationary sizing method, in general, oversizes
the fire PSV, and in cases with light hydrocarbons tends to undersize the fire PSV.
It is found that a dynamic sizing method is advantageous when sizing a fire PSV.