1. Inflation test: When the inner diameter of the oil pipe is less than or equal to 9.53mm, the minimum expansion pressure is 1.72MPa, the maximum working pressure of the oil pipe should be 0.34MPa; the minimum expansion pressure when the inner diameter of the oil pipe is greater than 9.53mm is 1.20MP, the oil pipe The maximum working pressure should be 0.24MPa.
2. Negative pressure test: the oil pipe with inner diameter less than 12.70mm shall withstand the negative pressure of 81kPa, and the oil pipe with inner diameter from 12.70mm to 25.40mm shall withstand the negative pressure of 34kPa, and there is no requirement for the oil pipe with inner diameter greater than 25.40mm. Select a pipe with a straight line length of 1 m. In the test, the pipe diameter shrinks by no less than 20% in 15 seconds, and the test time does not exceed 60 seconds.
3. Cold flexibility (for straight oil pipes with internal diameter less than or equal to 19.05mm): Two oil pipes are required for testing, one is not aged, and one is immersed in ASTM No. 3 oil for 70 hours (125 ° C). The unaged oil pipe was placed in a -40 ° C environment for 5 hours, and then the oil pipe was bent 180 degrees along the center line in the refrigerator (the bending radius was 10 times the outer diameter of the oil pipe); the aged oil pipe was placed at -34 ° C environment For 5 hours, then the tubing was bent 180 degrees along the centerline in the cold room (the bend radius was 10 times the outer diameter of the tubing). The bend is required to be held for 4 seconds and there are no cracks, cracks and breaks in the tubing and outer layer. A pressure of 0.68 MPa was applied to check the tubing for damage. (For a straight oil pipe with an inner diameter of 19.05 mm): Remove six 100 X6 mm samples from the pipe wall___, and place the three sections in ASTM No. 3 oil for 70 hours (125*C) and the other three sections at -40C. 5 hours in the environment (three sections of tubing lined up in an unclosed loop); the aged tubing was placed in a -34 ° C environment for 5 hours in the same manner as before. Then quickly reduce the spacing between different tubing to 25.4mm, requiring the tubing to continue and not break.
4. Tensile strength and ductility
A. Original tensile strength of the outer layer: 7.0MPa
B. Original tensile strength of the tubing: 8.0MPa
C. Overall ductility: 200%
5. Resistance to dry heat: heat aging for 70 hours (125*C) according to ASTM D573, tensile strength and ductility
The reduction shall not exceed the limits in Table 9.
6. Oil resistance: The tubing is immersed in ASTM Class C gasoline for 48 hours at room temperature (23 ° C). The physical properties of the tubing shall not exceed the limits in Table 9.
7. Anti-Oil: The oil pipe is immersed in ASTM No. 3 oil at a temperature of 125 ° C for 70 hours. The physical properties of the tubing shall not exceed the limits in Table 9.
8. Oil pipe evaporative test
8.1 Instruments: ASTM Class C fuel (50:50 for toluene and isooctane), 99% pure methanol, graphite crucible, glass filter, beaker, metal rod and pin.
8.2 Specimen: The test tubing has a length of 300 mm and a metal ring at both ends.
8.3 Test procedure
8.3.1 Record the actual inner diameter, length and internal surface area of the tubing.
8.3.2 Fill the tubing with ASTM Class C gasoline
8.3.3 Sealed at both ends for 24 hours at room temperature
8.3.4 Then put the oil in the tubing into the beaker
8.3.5 Refill the tubing with oil
8.3.6 Heat the tubing to 80 ° C to 95 ° C to evaporate all the oil from the outer layer.
The tubing was placed in a 23 ° C fume hood for more than 16 hours.
8.3.7 Take 30 mL of the remaining oil and add it to methanol at room temperature.
8.3.8 Wash the crucible and beaker twice with 10mL (at room temperature)
8.3.9 Place the crucible in a beaker and heat to 65 ° C to 90 ° C to completely evaporate the methanol.
8.3.10 Weigh the crucible and the beaker to define the surface evaporation rate
9. Anti-ozone: For straight oil pipes with an inner diameter of 2540 mm or less, the pipe length is required to be guaranteed to bend eight times the outer diameter, and the ends are covered with a copper ring or an aluminum ring. Place the sample in an ozone-free environment for 24 hours (temperature 23*C), then place the sample in an ozone-containing test chamber for 70 hours (temperature 40*C), then take it out and cool it to room temperature with a magnification of 7 times. Check that the part near the metal ring is negligible. For a straight oil pipe with a diameter of 25.40 mm, cut the tubing into strips 12.7 mm wide and 100 mm long, and then tie the strips to a shaft with a diameter of 12.7 mm. The next treatment is the same as the whole tubing. Check the condition of the tubing.
10. Attachment test: The minimum load of the tubing is 27N per 25 4mm width.
11. Anti-kink: The ball with a diameter of half the inner diameter of the oil pipe is freely passed through the oil pipe, and a plate with a thickness of 19 mm is used as a jig. The center distance of the hole is shown in the attached table. Test conditions: a tubing of 300 mm length was placed at room temperature of 23 ° C for 2 hours, then one end of the tubing was inserted into the hole of the plate, the other end was inserted into the other side of the plate, and then the tubing was bent into a natural beard, and The projection of the other side of one end of the plate is 63 mm long. Finally, ensure that the ball passes freely through the tubing.