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  • Simple and quick ckeck-up
  • All sizes from DN 06 - DN 25

DORNVOS

Checking the Operability of the Crimped Fitting by Measuring the Reduction of the Nipple Diameter (VWN VS 1.2)

Correct use of the test mandrel and the resulting potential change of the inside nipple diameter
Fig. 1.

The inside nipple diameter is reduced excessively in the sealing zone through the crimp dimension, which is too tight.
ATTENTION: This crimped fitting is not functional.
This error might result in premature failure of the hose line. The crimp diameter must be increased by several tenths of a millimeter!

Fig. 1. Excessive crimping, maximum reduction of nipple diameter exceeded

Fig. 2.

This illustration shows the maximum permissible reduction of the inside nipple. The crimp diameter should not be reduced any further, since otherwise there might be the risk of a premature failure of the hose line!

Fig. 2. Maximum reduction of nipple diameter reached

Fig. 3.

The perfect reduction of the nipple diameter has been reached. The crimp diameter should not be changed any more. It must, however, be checked prior to any change of the hose batch. The reached crimp dimension will correspond to the standard crimp dimensions as determined from the press dimension table.

Fig. 3. Ideal reduction of nipple diameter

Fig. 4.

This illustration shows the minimum permissible reduction of the inside nipple diameter. In this case, it is still possible to reduce the crimping diameter by a few tenth of a millimeter!

Fig. 4. Minimum reduction of nipple diameter

Fig. 5.

Crimping did not cause any reduction of the inside nipple diameter. The crimping diameter is too large.
ATTENTION: This crimped fitting is not functional.
There is a risk of a leak or of the hose slipping off the crimped fitting. It is necessary to decrease the crimping diameter by several tenths of a millimeter!

Fig. 5. No reduction of nipple diameter

Applicable standards:
DIN 3852, EN 853, EN 856, DIN 3859, EN 854, EN 857, DIN 20 066, EN 855, EN 982