Cleaning and Passivation
Cleaning Process Examples
34
Operating Instructions · Control Valve A
Edition 2016-06-07
Cleaning Parameters
The cleaning effect depends on the following factors:
•
Temperature
•
Time
•
Mechanics
•
Chemicals
•
Degree of soiling.
These factors can be combined in various ways to achieve an optimal cleaning result.
Please define the cleaning parameters yourself in accordance with your product and
process and regularly verify the result.
We recommend a flow velocity of at least 2 m/s.
Passivation
Before commissioning a plant, passivation is commonly carried out for long pipes and
tanks. Valve blocks are usually excepted from this.
Passivation is typically performed using nitric acid (HNO
3
) at approx. 80°C (176 °F) at a
concentration of 3 % and a contact time of 6 to 8 hours.
