Liquefied petroleum gas (LPG) storage tanks are often provided with water sprays to protect them in the event of a fire. This protection has been shown to be effective in a hydrocarbon pool fire but uncertainties remained regarding the degree of protection afforded in a jet fire resulting from a liquid or two-phase release of LPG. Two projects, sponsored by the Health and Safety Executive, have been undertaken to study, at full scale, the performance of a water spray system on an empty 13 tonne LPG vessel under conditions of jet fire impingement from nearby releases of liquid propane and butane. The results showed that a typical water deluge system found on an LPG storage vessel cannot be relied upon to maintain a water film over the whole vessel surface in an impinging propane or butane jet fire scenario. The deluge affects the fire itself, reducing the luminosity and smoke, resulting in a lower rate of wall temperature rise at the dry patches, when compared with the undeluged case. The results of these studies will be used by the HSE in assessing the risk of accidental fires on LPG installations leading to boiling liquid expanding vapour explosion (BLEVE) incidents. (C) 2003 L.C. Shirvill. Published by Elsevier Ltd. All rights reserved.