In the summers of 2000 and 2001, a series of controlled fire tests were conducted on horizontal $1890liter$ (500 US gallon) propane pressure vessels. The test vessels were instrumented with pressure transducers, liquid space, vapor space, and wall thermocouples, and an instrumented flow nozzle in place of a pressure relief valve (PRV). A computer controlled PRV was used to control pressure. The vessels were heated using high momentum, liquid propane utility torches. Open pool fires were not used for the testing because they are strongly affected by wind. These wind effects make it almost impossible to have repeatable test conditions. The fire conditions used were calibrated to give heat inputs similar to a luminous hydrocarbon pool fire with an effective blackbody temperature in the range of $850°C±50°C$. PRV blowdown (i.e., $blowdown=poppressure−reclosepressure$) and fire conditions were varied in this test series while all other input parameters were held constant. The fire conditions were varied by changing the number of burners applied to the vessel wall areas wetted by liquid and vapor. It was found that the vessel content’s response and energy storage varied according to the fire conditions and the PRV operation. The location and quantity of the burners affected the thermal stratification within the liquid, and the liquid swelling (due to vapor generation in the liquid) at the liquid∕vapor interface. The blowdown of the PRV affected the average vessel pressure, average liquid temperature, and time to temperature destratification in the liquid. Large blowdown also delayed thermal rupture.

1.
Townsend
,
W.
,
Anderson
,
C. E.
,
Zook
,
J.
, and
Cowgill
,
G.
, 1974,
Comparison of Thermally Coated and Uninsulated Rail Tank-Cars Filled With LPG Subjected to a Fire Environment, FRA-OR&D 75–32
, U.S. DOT Report.
2.
Moodie
,
K.
,
Cowley
,
L. T.
,
Denny
,
R. B.
,
Small
,
L. M.
, and
Williams
,
I.
, 1988, “
Fire Engulfment Test of a 5 Tonne LPG Tank
,”
J. Hazard. Mater.
0304-3894,
20
, pp.
55
71
.
3.
Balke
,
C.
,
Heller
,
W.
,
Konersmann
,
R.
, and
Ludwig
,
J.
, 1999,
Study of the Failure Limits of a Tank Car Filled with Liquefied Petroleum Gas Subjected to an Open Pool Fire Test, BAM Project 3215
,
Federal Institute for Materials Research and Testing (BAM)
.
4.
Droste
,
B.
, and
Schoen
,
W.
, 1988, “
Full Scale Fire Tests With Unprotected and Thermal Insulated LPG Storage Tanks
,”
J. Hazard. Mater.
0304-3894,
20
, pp.
41
54
.
5.
Appleyard
,
R. D.
, 1980,
Testing and Evaluation of the Explosafe Explosion Suppression System as a Method of Controlling the Boiling Liquid Expanding Vapour Explosion, TP 2740
, Transportation Development Centre, Transport Canada.
6.
Birk
,
A. M.
,
Cunningham
,
M. H.
,
Ostic
,
P.
, and
Hiscoke
,
B.
, 1997,
Fire Tests of Propane Tanks to Study BLEVEs and Other Thermal Ruptures: Detailed Analysis of Medium Scale Test Results, TP 12498E
7.
Birk
,
A. M.
,
VanderSteen
,
J. D. J.
,
Davison
,
C.
,
Cunningham
,
M. H.
, and
,
I.
, 2003,
PRV Field Trials—The Effects of Fire Conditions and PRV Blowdown on Propane Tank Survivability in a Fire, TP 14045E
8.
Birk
,
A. M.
, and
Cunningham
,
M. H.
, 1996, “
Liquid Temperature Stratification and its Effect on BLEVEs and their Hazards
,”
J. Hazard. Mater.
0304-3894,
48
, pp.
219
237
.
9.
Pierorazio
,
A. J.
, and
Birk
,
A. M.
, 1998,
Evaluation of Dangerous Goods Pressure Relief Valve Performance—Phase II: Full Scale Transport PRV Tests, TP 13259E
10.
Birk
,
A. M.
, and
Cunningham
,
M. H.
, 1994,
A Medium Scale Experimental Study of the Boiling Liquid Expanding Vapour Explosion, TP 11995E
11.
Pierorazio
,
A. J.
, and
Birk
,
A. M.
, 1998,
Evaluation of Dangerous Goods Pressure Relief Valve Performance—Phase II: Small Vessel PRV Tests, TP 13259E
12.
Rew
,
P. J.
,
Hulbert
,
W. G.
, and
Deaves
,
D. M.
, 1997, “
Modelling of Thermal Radiation From External Hydrocarbon Pool Fires
,”
Trans. IChemE, Part C
0960-3085,
75
(B),
81
89
.
13.
AIChE
, 1994,
Guidelines for Evaluating theCharacteristics of Vapor Cloud Explosions, Flash Fires and BLEVEs
, AIChE Centre for Chemical Process Safety, New York.