UL-1489:2016 pdf free download – STANDARD FOR SAFETY Fire Tests of Fire Resistant Pipe Protection Systems Carrying Combustible Liquids.
5.5 Furnace thermocouple preparation
5.5.1 Each furnace thermocouple is to be enclosed in a sealed protection tube. The exposed combined length of protection tube and thermocouple in the furnace chamber is not to be less than 12 in (305 mm). Other types of protection tubes can be used provided that the temperature measurements are within the limits of accuracy specified in 5.5.2.
5.5.2 The time constant of the protected thermocouple assembly is to be within the range of 5.0 to 7.0 mm. A typical thermocouple assembly complying with the time constant requirement shall be fabricated by fusion-welding the twisted ends of 18 AWG (0.82 mm2) chromel-alumel wires, mounting the leads in porcelain insulators and inserting the assembly into a standard weight nominal 1/2-in (13 mm) diameter iron, steel, or inconel pipe, and sealing the end of the pipe that is inside the furnace. The thermocouple junction is to be inside the pipe, 1/2 in from the sealed end.
5.6 Sample temperature measurement
5.6.1 Temperature measurements are to be made by thermocouples placed at each of the following locations underneath the fire resistive pipe protection material, as illustrated in Figure 5.1.
Group A)
1) A minimum of two thermocouples evenly distributed around the perimeter of the
pipe at a point 1 in (25 mm) from the floor or wall surface facing the furnace;
2) A minimum of four thermocouples evenly distributed around the perimeter of the
pipe immediately adjacent to the pipe support;
3) A minimum of two thermocouples evenly distributed around the perimeter of the
pipe at a point 12 in (305 mm) from the floor or wall surface on the leg of the pipe;
4) A minimum of four thermocouples evenly distributed around the perimeter of the
pipe at the center of the pipe elbow;
5) A minimum of two thermocouples evenly distributed around the perimeter of the pipe
at a point 12 to 18 in (305 to 457 mm) from and on both sides of the pipe support; and
6) A minimum of two thermocouples evenly distributed around the perimeter of the pipe at a point directly beneath a representative joint or splice in the fire resistive protection material.
Group B)
1) At all anticipated hot spots on the pipe and at the discretion of the testing body.
5.7 Differential pressure measurements
5.7.1 General
5.7.1.1 The differential pressure between the exposed and unexposed surfaces of the floor or wall assembly is to be 2.5 Pa or controlled with ±20% of the intended value as outlined in 5.7.3.1 during the test (excluding the first 10 mm), and is to be measured at a point on each side of the floor or wall, 0.78 in (20 mm) from the surface of the assembly, as follows:
a) At the center and quarter points of the longitudinal center line for a floor assembly; and
b) At the center and quarter points of the vertical center line for a wall assembly.
5.7.2 Pressure measurement apparatus
5.7.2.1 The differential pressure is to be measured by means of a manometer or equivalent transducer capable of reading pressure within an accuracy of 0.01 in (2.5 Pa) of water.
5.7.2.2 The pressure measuring probe tips are to be as illustrated in Figure 5.2, or the equivalent, and manufactured form stainless steel or equivalent material.