API SPEC 6FB:1998 pdf download.API Specification for Fire Test for End Connections
3.1.2 Description of Fire Test (See Figure A-1)
3.1.2.1 The connection shall be tested with water. The total volume of water which is isolated in the test fixture shall not exceed the volume of a cylinder whose diameter is the nomi- nal test connection size and whose length is twice the nominal test connection size. The orientation of the axis of the bore may be vertical or horizontal. To qualify a connection design for bending as well as pressure, a second test is required. 3.1.2.2 Each connection shall be enveloped in flame and temperature measurements made by thermocouples and calo- rimeters. The test setup shall include a minimum of three calo- rimeter blocks and thermocouples equally spaced around the circumference in the plane of the joint, as shown in Figure A-2. The maximum spacing between calorimeters shall be 12 inches (300 mm) on the circumference. An additional calorim- eter block and thermocouple shall be placed on each side of the joint, at a distance of 3 / 2 of the length of the flange or twice the bore diameter, whichever is greatest, at a circumferential loca- tion which is furthest from any burner. The calorimeter blocks shall be 1 1 / 2 inch (38 mm) cubes made of carbon steel with a thermocouple located in the cen- ter of each cube, as shown in Figure A-4. 3.1.2.3 The test pressure shall be 75% of the API rated working pressure. 3.1.2.4 The burn period shall be at least 30 minutes from ignition. Detailed procedures are in Section 3.2. 3.1.3 Description of the Bending Test After 25 minutes of the burn period, an external bending moment shall be applied to one test connection. The moment which is sustained without causing leakage greater than the acceptable level shall be noted and reported. This will termi- nate testing on this connection. Figures A-5 and A-6 show two suggested means of apply- ing the bending moment. In using an arrangement like Figure A-5, the hydraulic ram will produce both a tension and a bending moment on the connection.
3.1.4 Leakage Measurements
Leakage of the test connection is to be positively collected and measured by means of a system as shown in Figure A-7. The connection shall be provided with a secondary seal out- side the main seal made of a high temperature material such as graphite or metal foil gasketing material. Two leakoff ports shall be drilled from the exterior of the connection to the region between primary and secondary seals, forming a closed chamber. The two connections shall be made on oppo- site sides of the test connection. Two equal-length pieces of tubing shall be connected to the leakoff ports, and a third equal length of tubing shall be blanked off and mounted on the test vehicle similarly to the other two. This third dummy line will be used to compensate for expansion of air in the leakoff lines. Each of the three lines shall pass in succession through a condenser, fluid trap and gas trap and shall terminate in a graduated cylinder for leakage measurements, as shown sche- matically in Figure A-7, if nitrogen gas is to be used to replace water in the valvebore, as provided for in 3.2.1j. If water is to be used throughout the test, the fluid and gas traps may be deleted and the discharge from the condensers con- nected directly to the graduated cylinder. The dummy line may also be deleted.
API SPEC 6FB:1998 pdf download
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