Water quality is one of the most important factors in determining the overall sustained performance of a steam sterilizer.

Why is water quality extremeley important?

Poor water quality can lead to a needlessly shortened boiler life, excessive maintenance costs, and unnecessary downtime for the hospital or laboratory.

In evaluating the Primus Service Call Log over the past three years, poor water quality has been the root cause of a significant percentage of the calls.

In most operating environments you will encounter, the quality of incoming feed water is determined by the following parameter: Total Dissolved Solids (TDS) – when minerals are dissolved in water, ions are formed.

The sum of all the minerals or ions in the water is the TDS.

Water Hardness – is the measure of calcium and magnesium content (measured as carbonate equivalents). Water Hardness is the primary source of scale build-up in the boiler and contamination of valve and plumbing surfaces. Primus recommends using supply water with hardness levels of 8 to 85 ppm.

Suspended Solids (SS) – represent the undissolved matter in water including dirt, silt, biological growth, vegetation, and insoluble organic matter.

Chlorides – significant chloride concentration in water can lead to rapid chloride stress corrosion in the stainless steel pressure vessel and ultimately cause leaks.

NOTE: Per the Primus Equipment Warranty, presence of chlorides voids the warranty.

Hence, chlorides must be prevented from coming in contact with the sterilizer!

Common solutions to poor water quality

Two methods that can be used to ensure high quality water is presented to the steam sterilizer are: Reverse Osmosis (RO) – a process where feed water is forced through three filters and a semi-permeable membrane leaving a concentrated solution of impurities which is rejected to waste.

Primus recommends R/O as the preferred solution for three important reasons:

1. Eliminates any Suspended Solids (SS)

2. Removes Chlorides

3. Greatly reduces Total Dissolved Solids (TDS)

Ion Exchange (Soft Water Conditioner) – the most widely used method of water treatment for producing saturated steam. Ion exchangers typically use a resin bed activated by passing a brine (sodium chloride) solution through it which leaves the resin bed rich in sodium ions.

The water to be softened is then pumped through the resin bed and ion exchange occurs. Harmful calcium and magnesium ions that cause hard scaling displace sodium ions from the resin, leaving the flowing water rich in sodium salts. The sodium salts stay in solution at very high concentrations and temperatures and do not form harmful scale in the boiler.

Periodically, the boiler is blown down to remove the resulting soft sludge build-up.

Water Quality Information for Carbon Steel Boilers

Learn more!

Learn how to install the PRIMUS PRIpure Reverse Osmosis system.

Have questions?

Email our resident PRIMUS sterilizer expert, Dave Schall to answer all of your questions. Contact Dave at Spire Integrated Solutions at 877.679.7800 x1212.

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