Cleaning and Disinfection of a Newly Purified Water System Before Start Up

• WHO require any newly installed pharmaceutical water distribution system to be degreased, passivated and periodically sanitized.
• The purpose of degreasing is to remove any greasy materials produced from the welding process
• The purpose of passivation of the interior surfaces of the loop is to form a barrier between the water and free ion and to re-establish the protective layer on the surface of the steel, which was removed by welding. (It is also good if you have a rouging problem).
• The purpose of sanitization is to control the microbial contamination and biofilm

1. Degreasing

• After the wedding, you will have to degrease it. As you know, pipes are quite dirty and also welding releases some "greasy" material. You can do this with a caustic based solution
• Charge the tank around 600 liters of PW and then add 15 Kgs of sodium hydroxide (100%). Mix with a rod, don’t use detergents to avoid foaming.
• Re-circulate the solution through the entire loop for 30 minutes: one hour, discharge and rinse the tank and loop with fresh water several times.

2. Passivation

• You need to Passivate the tank and the distribution loop. As you know, PW has a pH slightly acidic (about 6.5) so you need to Passivate the stainless steel to increase its resistance.
• Collect the storage tank about 600 liters of PW, add 20 liters of nitric acid (69%)Then recirculate the solution 30 minutes, drain the solution from the user points
• Collect the storage tank about 600 liters of PW, add 25 Kgs of citric acid (100%)Then recirculate the solution 30 minutes, drain the solution from the user points.
• Flush the circulation loop with purified water till the PH = 7.0 is achieved, use pH paper indicator and no traces of nitric acid or NaOH are present.

3. Sanitization

• Usually, you have two types of thermal sanitization: one at 80°C that is recirculating for 2 hours, and other at 121°C (a kind of sterilization) that recirculates for 30 minutes (For both you have to have the PW level in the tank of about 15%) then cool down.

Submitted By:
Mr. Ibrahim Hashim
Microbiology Manager-Sabaa Pharma Group-Egypt
002-0122635047
E- mail: ibrahimhashim71@yahoo.com

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