On May 4th, fire study No. 3 was conducted at the U.S. Pipe Product Innovation test facility in Bessemer, Alabama. This study was conducted on two 6-ft long 8-inch HDSS® pipes assembled with the joint positioned in the center of the assembly. A standard SBR TYTON JOINT® gasket was used. The pipe ends were capped with MJ caps with MJ restraining glands. This study was conducted to determine the fire resistance and the survivability of a gasketed restrained joint using a modified version of the following ISO standards: ISO 19921- Ships and marine technology- Fire resistance of metallic pipe components with resilient and elastomeric seals- test methods and ISO 19922 – Ships and marine technology- Fire resistance of metallic pipe components with resilient and elastomeric seals- Requirements imposed on the test bench.

The stated ISO standards were modified to closely simulate a wildfire type event and represent a worst-case scenario which exposes the joint to extreme heat for an extended period with a minimal amount of water flow through the pipe. The propane gas burner was spaced 6-inches below the pipe bell with a thermocouple spaced 5/8-inch below the pipe bell to read the flame temperature. The pipe assembly was suspended 43-7/8- inches above the floor. An additional thermocouple was placed in the out-flow to monitor the water temperature exiting the heated pipe.

Study Test # 3 (test ran with propane burner) was conducted with a burner flame temperature of approximately 1500 °F with a flow velocity of .025 GPM (gallon per minute) in the 8-inch pipe assembly for 45 minutes. Ambient air temperature was 86° F. The water temperature exiting the pipe started at 80° F and did not increase above 80° F during the test. No leaks were observed during the trial. When the pipe cooled the assembly was pressure tested to 500 psi for 5 minutes with no sign of leakage or failure. The joint was then disassembled and examined. No appreciable damage was observed to the pipe, joint restraint components, cement-lining, or gasket.

The fire study was conducted to prove that ductile-iron pipe, with standard SBR gaskets, can survive intense heat much longer than the expected 15-minute average wildfire time and continue providing safe drinking and fire protection water for our valuable customers without contaminating the water inside or polluting the environment with toxic fumes or chemicals.