1

Appearance

Visual inspection

1. The tube surface is shiny, free from small holes, cracks and impurities.

2. The inner wall is smooth and flat, no scratches and projection are allowed

                     2

Cold resistance bending test

1. Take 5pcs of corrugated conduit of 30cm length, store them in a low temperature box of -40°C for 4 hours.

2. Take them out, bend 180° along the mandrel with 4 times the inner diameter of corrugated conduit

And then observe the appearance change of the conduit

No appearance change is allowed like cracks,brittle rupture and chap which will affect the normal use.

                     3

Thermal aging test

Test equipment: Heat aging box

Test method: store 5pcs of 30cm corrugate conduit in the corresponding hot air

Storage time ≥ 500H or 240H

No cracks, brittle rupture or chap is allowed when the corrugated conduit is bent with the inner diameter of the tested sample.

                      4

Thermal deformation

Test method:

1.Take 5pcs of 20cm corrugated conduits, and mark the middle at 10cm.

2.Store the corrugated conduit in a temperature of 120±3℃ for 24 hours.

3.After that,cool the test sample in an environment of 23℃ temperature and 50% relative humidity for 30 minutes .

4. Measure the length of the corrugated conduit with a vernier caliper, and calculate the result.

The maximum deformation rate must be less than or equal to 10%

                   5

Impact test

1. Put the wire bundle into a 38cm long corrugated conduit. The wire bundle should not occupy over 80% of the corrugated conduit.

2. Keep the test sample at the environment of 23 ± 3 ℃ and 50% relative humidity for 30 minutes.

3. After step2, take out the sample and fix it on the V-shaped guide groove. Use an one meter height guide tube, have the steel-ball free fall from the top of the tube to the wire bundle. Check the result. 

                  6

Chemical Resistance Test

Chemical resistance refers to the resistance of tubes to various medium erosion. Experiments should be carried out according to the provision of the standard JT/T1031-2016.

1. Inject the testing reagent into a chemical-resistant sprayer.

2. Take a 38cm length corrugated conduit,vertically place it and and spray the reagents on the surface of the test sample.

3. Place the test sample at the temperature listed in Table 3 for 20 hours to allow the sprayed reagent to drip dry. The test box used should meet the requirements of JB/T 7444.

4. Wind the test sample twice on a shaft with a diameter of 4 times the inner diameter of the test samples.

Keep it at room temperature for 30 minutes, visually inspect the tested sample to check whether there are cracks, melting or other deformations on the surface.

Tested samples must not be deformed or cracked

                        7

Long-term Thermal aging test

Free hanging two pieces of 50cm corrugated conduit at corresponding hot air for more than 3000 hours.

Tested samples are not allowed to have brittle rupture or chalk.

No breakage, crack or defects affecting the using when the corrugated conduit is bent with a radius of 2 times the outer diameter of the corrugated conduit at normal temperature.

                       8

Combustion performance

UL94     GB/T 2408      FMVSS 302     GB/T 8410      EN 45545       DIN 5510