Code Approval of Composite Propane Cylinders for Indoor Use ...

esulting in flashover conditions in the test room. In one test, an additional spare cylinder waspositioned next to the heater to evaluate the effects of radiant heat on the composite cylinder.The increases in temperatures, ensuing from the fire growth, were measured and the performanceof the heating appliance was assessed.The final test was to assess the performance of a burning pressurized cylinder when impacted bya water hose stream. Two igniters were attached to a composite cylinder, filled to half of itscapacity with water, was pressurized by nitrogen following a predetermined cylinder pressuretimecurve obtained in Type-2 tests. The cylinder was impacted by a water hose stream when acylinder pressure of 220 psig was reached, six minutes into the test. The cylinder breachedbefore the hose stream impact. However, the hose stream impact did not cause additional damageto the cylinder.The key findings of the second test program were:Fire hazard from empty or filled stored cylinder:1. The maximum heat release rates from the ignition and burning of the empty cylinderswere approximately 100-120 kW.2. The maximum smoke release rates were 0.65 m 3 /s for cylinders from onemanufacturer and 2.65 m 3 /s for the other manufacturer’s cylinders.3. A full stored cylinder sustained the radiant heat from a 300 kW fire for 20 minuteswithout being ignited or leaking propane (Type-3 test).4. A burning, nitrogen pressurized stored cylinder did not violently breach or rupturewhen impacted with a water hose stream.Contribution of leaking gas from an ignited cylinder to fire hazards in a room fire:5. In each of the fire tests (Type-2), the ignited composite cylinder in the heaterassembly released gas resulting in flashover conditions in the room.6. In a growing room fire that goes to flashover (Type-3), the composite cylinderbreached and ignited after the flashover had occurred. Typically, there was a three tofive minute lag. between room flashover and breach of the cylinder. The leaking gascylinder did not rupture.7. Once the cylinder started to leak, the release of gas continued during the test. A fullcylinder was emptied approximately 10 to 15 minutes after the maximum pressurewas reached.Rupture hazard from propane filled cylinder:8. Cylinder design played a role in its fire performance. In one of the Type-2 tests, arupture of a two-piece cylinder occurred 17 minutes into the test, at a pressure of 46psig. The rupture occurred when the pressure level was decaying; eight minutes afterthe pressure had reached its maximum level of 243 psig. The burst resulted in severeComposite Propane Cylinders vii February 2007for Indoor Use — Phase IIBattelle