The Fire Chamber
AERO NAV LABORATORIES has designed and constructed a fire chamber for flame testing items, such as hydraulic hoses,
utilizing its own engineering resources.
The chamber is utilized to:
•Test the fire flame resistance of items such as protective sleeving on hydraulic hoses while flowing heated, pressurized
water. It tests the ignition resistance and burning characteristics of the material.
•Subject materials to elevated temperatures
•Subject materials to direct flame impingement. The chamber demonstrates the response of materials and products under
controlled flame conditions.
The chamber consists of the components shown in the schematic below. It consists of a bank of jets supplied with propane
gas at a pressure of 50 psi. The specimen under test is placed in the chamber above the gas jets. The circulating water is
heated and pressurized by the heater and pump to a maximum temperature of 80 degrees C (176 degrees F) and
pressurized to 72.5 psi. The maximum propane gas temperature is 800 degrees C (1472 degrees F).
Hydraulic hoses are often provided with protective fire resistance sleeving. The protective sleeving is typically rated, as “fire
resistant”, not “fire proof”. That is, it must remain tight (no leakage allowed), under the flame and circulating water
conditions for a period of time, typically 30 minutes. This time frame allows for a fire extinguishing system to sense and
extinguish the fire. Furthermore, it must pass a hydrostatic pressure test at 1.5 or 2 times the operating pressure for a ten
minute period, after the fire test. The choice of pressure is dependent upon customer requirements. It is important to note
that some degradation, such as charring of the protective sleeve, is allowed providing it meets the above criteria of no
leakage, and passing of the hydrostatic pressure test.
The chamber can also be used to evaluate the effects on the material of the elevated temperatures and direct flame