Lesson 7 - Hygienic Design SAQ
This lesson enables you to test yourself on the material covered in the lesson on Hygienic Design and to determine the level to which you have met the learning outcomes.
Suggested Response - Q1
*Indicate whether the following statements are true or false. Provide a reason if they are false.
a) In order to be hygienic a valve must incorporate a hermetic seal.
b) Hygiene organisations enforce legislation.
c) Hygienic design is only concerned with equipment cleanability.
d) In order to be classed as hygienic the surface roughness of a material should not exceed 0.8 µm.
e) Larger diameter pipes are more hygienic.
f) Eccentric reducers should be used in piping.
g) All butterfly valves are hygienic.
h) To ensure cleanability, gaps between equipment and walls should be kept as small as possible.
Response:
a) False. In order to be hygienic, equipment must be able to be effectively cleaned in place. Hermetic seals are only required for ultraclean or aseptic equipment.
b) False. Hygiene organisations provide guidelines and certification. They do not enforce compliance.
c) False. Whilst equipment cleanability is an important component, other elements such as the prevention of contamination are just as important.
d) True.
e) False. Larger pipes can result in lower velocities which can lead to greater deposits of solids. Higher velocities are also required in order to ensure effective cleaning.
f) True.
g) False. Valves have to comply with the hygienic requirements in order to be classed as hygienic. Thus, if a butterfly valve does not comply it will not be classed as hygienic.
h) False. The gaps should be as large as possible for effective cleanability.