Preparation and purification of water in the central sterilization department plays an important role, which depends on the stable quality of washing and sterilization of instruments, as well as the operation and operation of the main equipment in the CSSD:
❖ Washing of disinfection machines
❖ Steam sterilizers
❖ Low-temperature sterilizers (formaldehyde and plasma)
❖ Ultrasonic sinks
❖ Guns for rinsing materials and filling ultrasonic sinks
Water purification directly affects the quality of all equipment and ensures the purity of materials from plaque, fine sludge, scale and salts. Therefore, tap water in hospitals must be treated to the required quality parameters. Cooling water should not be corrosive, and should not contain abrasives or form deposits. Even small amounts of salts, chlorides, phosphates or metals can cause a variety of problems. Iron, manganese and silicon are deposited on sterilized instruments, in the sterilization chamber and the steam generator. Chlorides and salts cause corrosion and shorten the life of equipment; calcium and magnesium cause the accumulation of limescale and blockages. Other substances can form non-condensed gases in the steam, endangering the efficiency of sterilization.
The water treatment and purification system works in automatic mode with control of electrical conductivity and pressure in the system.
Water purification is performed in several stages:
❖ Mechanical filtration
❖ Coal filtration
❖ Mitigation
❖ Reverse osmosis filtration
❖ Disinfection with an ultraviolet lamp
Types of water used for CSSD operation:
❖ Cold water
❖ Hot water
❖ Softened cold water (with low tap water quality, softened water is supplied instead of cold water and preheated instead of hot water)
❖ Purified water (demineralized or after reverse osmosis)
Cold water:
Served on a washing and disinfection machine, the function of which is to soak and wash materials and instruments in the previous phases of washing.
Hot water:
Served on a washing and disinfection machine, the function of which is to wash materials and instruments in the intermediate phases of washing.
Softened cold water (instead of cold water):
❖ Served in a washing and disinfection machine, the function of which is to soak the materials in the previous phases of washing. It is also fed through the heating boiler to the washing and disinfection machine for the intermediate phases of washing.
❖ Served in a steam sterilizer for operation of the vacuum and cooling system of the sterilizer.
Quality and characteristics after softening cold water:
To achieve maximum performance and service life of the sterilizer, the requirements listed in the table must be met.
Recommended water temperature for steam sterilizer operation:
From 0 °C to 15 °C
Recommended range for the best steam sterilizer performance. The lower the temperature, the better the performance.
From 15 °C to 20 °C
Reduction of vacuum depth and cooling productivity of the steam sterilizer, which leads to a longer cycle times and higher water consumption.
From 20 °C to 35 °C
Not recommended for steam sterilizer operation.
The hardness of the water should not exceed 4dH / (0.7 mmol/l) / (70 ppm).
Purified water:
❖ Served in a washing and disinfection machine, the function of which is the final rinsing of materials and instruments.
❖ Served in a steam sterilizer to operate the steam generator and produce clean steam.
It is fed to the gun for washing under pressure of tubular materials, washing of the tool in washing sinks and filling with the gun with water in an ultrasonic sink.
Quality and characteristics after water purification:
Requirements Recommendations
Acidity pH from 5 to 7
Conductivity ≤5-20 μS / cm
Hardness ≤ 0.02 mmol / liter (corresponding to 0.1 dH or 1.8 ppm)
The main components of the automatic water purification system:
❖ Mechanical filter, rough cleaning: 130-150 microns
❖ The filter is coal, automatic: 1-2 cubic meters / hour
❖ TWIN softener, automatic: 1-2 cubic meters / hour
❖ Installation of the return osmosis, automatic: 250-500 l / h
❖ Ultraviolet lamp: 1-2 cubic meters / hour
❖ Pumping station (2-3 units depending on the inlet pressure of tap water)
❖ Capacities are plastic (300 l, 500 l, 700 l, 1000 l)
❖ Shut-off valves
❖ Manometers, conductometer
❖ PVC pipelines
❖ Supply voltage 220V
❖ Power 3.5-5.5 kW
❖ System outlet pressure 4-6 bar
