For the lazy people...
5. Conclusions of the executed audit.
The executed examination of production process, control process and acceptance process
of 1.1 L composite tanks did not display any infringements. All tests verifying the quality
of composite tanks manufactured by STAKO Sp.j. were passed positively.
During the inspection, no explicit cause of leakage of tanks revealing itself during exploitation
was established. The place, which could be at risk of cracking, because of variable
loads when the tank is being filled or emptied, was the region of the neck of the head at the
point of contact of the liners material and aluminium element.
Because of repeatability of forming the plastic layer in the form, no explicit reason of
inequality in plastic coating at the point of the contact of the liner with the aluminium element
was pointed.
In FMEA STAKO presented the factors, which could have a potential effect on formation
of leakages in the tanks.
STAKO implemented the recommended improvement actions listed in FMEA into production
process.
After implementation of changes thermoplastic liners and finished tanks were manufactured,
and STAKO conducted production tests on them.
Performed actions did not display differences in the quality of manufactured tanks, because
examination results before and after implementation of changes in the production process
were consistently positive.
Changes of production process suggested in FMEA were introduced by STAKO permanently
into the tank manufacturing technology.
As a result of the executed audit TÜV NORD representative stated, that STAKO sufficiently
fulfilled the efforts needed to detect possible reasons which might induce single incidents
of tank leakage and introduced improvement actions into the production process basing
on FMEA.
Resuming production of mentioned tanks, which was suspended on 22.05.2007 by
Quality Assurance Team until analysis of the production and control system, construction of
the liner with a set aluminium head element, as well as finished tank, during production period
following introduction of changes in technological process, should be covered with increased
level of control, in order to determine the effect of changes on the increase of the
tank operation safety.
Because of that, the TÜV NORD representative recommended, especially in that period:
- introduction of additional changes into the composite tank control plan in operation no 140
pos 79-82, with regard to detection of the liner faults, which could affect the tank operation
safety, with additional control of quality control division,
- introduction of internal endoscope inspection of the point of contact of the liners neck with
the aluminium head element,
- covering the control regarding quality and portioning of plastic for tank production with the
activities of quality control divisions.
Artur Kaszczuk
Appraiser
TÜV NORD POLSKA
