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Pipes and Pipe Fittings

1、 Fill in the blank questions

1The pipe specifications are expressed as de (nominal outer diameter) * e (nominal wall thickness).

2The wall thickness deviation of the same section of the pipe shall not exceed 14%.

3The two ends of the pipe should be cut flat perpendicular to the axis.

4According to GB2918, adjust the state of the sample at 23+2 ° C for 24 hours and conduct the experiment under the same conditions.

5When measuring the maximum and minimum diameters, measurements should be taken at different locations on the same section until the maximum and minimum values are obtained.

6The degree of curvature of rigid plastic pipes in the length direction, expressed as a percentage of the ratio of the maximum height of the arc to the length of the pipe.

7If the wall thickness of the pipe is less than or equal to 12mm, the sample shall be made by punching or mechanical processing methods.

8Selection of samples: According to the requirements of different material product standards, samples are selected to be made from the middle part of the spline using punching or mechanical processing methods.

9The yield stress is actually calculated based on the cross-sectional area at yield, but for convenience, the original cross-sectional area of the specimen is usually taken for calculation.

10The micrometer is used to measure the depth of the pressure needle into the sample, with an accuracy of less than or equal to 0.01mm.

11True impact rate: When testing the entire batch of products, the total number of impact failures divided by the total number of impacts is the true impact rate.

12If the number of impact failures of the sample is in Zone A, it is determined that the TIR value of this batch is less than or equal to 10%.

13In the longitudinal shrinkage rate, take a (200+20) mm long pipe section as the sample.

14The socket size of fittings such as elbows and tees should also comply with the provisions of Table 1, and the wall thickness of the fittings should be greater than or equal to the minimum wall thickness of the same pipe specified in GB5836.1.