Laboratory

The HAWLE laboratory continuously performs various tests to ensure quality workmanship. Raw materials are checked for their suitability, samples are taken at random and checked during each production step and finished goods are subject to periodic tests, audit and review. Both destructive and non-destructive procedures are applied in order to yield those test results needed to determine the product’s quality level and carried out according to HAWLE test methods by specially trained and experienced staff. All test results are documented and corrective measures are initiated if necessary.

Some of the tests used are:

laboratory_hawle_5_en 100% pressure testing corrosion test practice test burst test tensile tests

Tensile tests

Start of tensile test
Constriction of the PE pipe
Elongation of the PE pipe
Grip markings after the test

Tensile tests are performed in the HAWLE laboratory. The purpose of the tensile test is to investigate the function of fittings during extreme mechanical stress in order to ensure operational practice. In this test, a 1" ISO-fitting and 1" HAWLE-FIT are connected to each side of a polyethylene pipe. The special chamber in each fitting is designed to increase the force applied by the grip ring onto the PE pipe with increasing pressure.

The difference between ISO-fitting and HAWLE-FIT is that the pipe can be inserted directly into HAWLE-FIT and tightened immediately whereas for the ISO-fitting the pipe must be chamfered and moistened prior to insertion. For fittings intended for gas pipes, a support liner is used in order to simulate the increased safety measures required. Support liners are generally not required for HAWLE products intended for drinking water pipelines, except for those instances where negative pressure (vacuum) could occur.

During the tensile test, the grip ring never damages the pipe surface. This is important because any damage to the pipe at the grip site creates a weak point which could result in release of the pipe. Furthermore the grip ring never releases the pipe during increased tensile pull but rather on the contrary the pipe is always the weaker component.