Risk analysis / residual risks directive 97/23/EC,
Appendix I, Section 1-3
All the components and apparatus in the 2002 edition of the QVF catalogue have been subjected to a risk analysis in accordance with Directive 97/23/EC and the corresponding countermeasures are documented by QVF. To exclude risks above and beyond these resulting from improper use (Directive 97/23/EC, Appendix I, Section 1-3) the following points should be observed:

• Although borosilicate glass 3.3 is a material resistant to virtually all chemical attack, alkaline solutions, hydrofluoric acid and concentrated phosphoric acid can cause some erosion. If there is any concern that there may be a reduction in wall thickness, the required minimum wall thickness should be checked at regular intervals.
• Unstable fluids, substances that can decompose, call for special safety precautions in the use of glass plant.
• The permissible operating conditions in accordance with section 1 the catalogue, page 1.6, should be observed and compliance ensured if necessary by means of additional measures such as pressure relief valves, bursting disks, over-fill preventi on or temperature limiters.

  
  - Permissible operating pressures:
  The permissible operating pressure should be observed in every case, including when commissioning, checking for leaks and filling the plant.
  
  - Permissible operating temperature:
  The maximum operating temperature for glass components is 200°C and this should be observed and where necessary, e.g. with electrical heating or exothermic reaction, ensured by the use of suitable measuring equipment.
  
  - Permissible thermal shock:
  Borosilicate glass can withstand thermal shocks up to 120 K.
  For plants operating at temperatures in excess of 120 °C, and which are not protected by insulation, the thermal shock limit could be exceeded by cold water sprayed onto the equipment by a sprinkler system. To avoid this, sprinkler heads should not be mounted in the vicinity of unprotected glass process plant. In the event of a fire high temperatures may arise which could also result in breakage of the glass.
  
  

• Extra loads,
  such as reaction forces on side branches, are not permissible. Bellows should be included in interconnecting pipework to ensure a stress-free connection to the glass plant.
• Mechanical damage / protective measures:
  The tubular structure supporting the equipment or plant also provides protection against damage from external sources and prevents other items coming into contact with it.
  Parts of the plant which are located outside the structure must be protected against mechanical damage. Parts of the plant, which can reach a surface temperature higher than 60 °C in operation and which are located outside the support structure, must be provided with protection against contact.
  Additional safety devices are available in the form of safety screens, spray guards, coated and wrapped glass components (see section 1 of the catalogue, pages 1.11 and 1.12).
• Damage to heat exchangers:
  Should damage occur to the coil batteries in coil type heat exchangers or the heat exchange tubes in shell and tube heat exchangers, the service fluid and product can become mixed.
  Media, which could react resulting in the generation of pressure and temperature (exothermic processes), should therefore be kept separate.