Water treatment: how to choose the product for boilers and circuits

The right product depends on what you want to prevent: limescale is prevented with a scale inhibitor, corrosion with a corrosion inhibitor, dissolved oxygen in the boiler with an oxygen scavenger. If the limescale has already been deposited, you need an acid descaler instead, with a pH close to 1. For swimming pool water, chlorine, flocculants and pH correctors are used. Before buying, have the system water analysed: that gives you the product and the dose.

Types

• Corrosion inhibitors: they protect the metal of boilers and circuits. An example is the Chemical Roadmaster Amin Vap inhibitor.
• Scale inhibitors and dispersants: they stop limescale from depositing on exchangers and pipework, for example in cooling systems. Like Sequestrol Bio.
• Acid descalers: they dissolve limescale that has already formed. They are aggressive products, to be used with caution.
• Oxygen scavengers and dealkalisers: they remove dissolved oxygen from boiler water, which is one of the main causes of corrosion. There are also volatile versions.
• Liquid conditioners: preparations that treat boiler water as a whole.
• Preservative fluids and concentrated antifreeze: used to preserve and protect circuits.
• Chlorine, sanitisers and pH reducers: for swimming pool and process water. In the collection you will find the FP 56 dichloroisocyanurate, the FP 90 trichloroisocyanurate, the Perfloc L flocculant and correctors such as PH Meno.

How to choose for the job

In practice the path is always the same: water analysis, choosing the product according to the problem (limescale, corrosion, oxygen, hygiene), choosing the form (liquid, powder, tablets) according to how you dose, and periodic checks of the parameters with dose correction if needed. If the system has several problems at once, a liquid conditioner that treats them in a single product simplifies dosing; if the problems are separate, it is often better to keep the products separate.

What to look for

• pH: in the collection it ranges from below 1 to 13. Low values indicate acid products (descalers, pH reducers), high ones alkaline products. It is needed to choose the materials of the dosing equipment and the protective equipment.
• Physical state: liquid in most cases, but there are also powders, granules, egg-shaped pellets and 200 g tablets. Solids are dosed differently from liquids.
• Density: from about 1 to over 2 kg/l. You need it to convert litres and kilograms when calculating the dose.
• Pack size: from 5 kg up to 210 kg drums and 1000 kg containers. For a small system the drum is not worthwhile, for a large one it is.
• Smell and colour: useful for recognising the product, but not for choosing it. Some inhibitors have an amine smell, others are odourless.

Common mistakes

• Choosing without a water analysis. Hardness and pH change from area to area, and the right dose changes with them.
• Mixing different products. Especially chlorine and acid products: they must never be brought into contact, because chlorine gas can be released.
• Using an acid descaler on materials that cannot withstand it. Check the data sheet for which metals it is compatible with.
• Dosing by eye. Too little does not protect, too much can cause damage. A dosing pump is better.
• No longer checking the parameters. The dosage must be reviewed with periodic checks, not fixed once and for all.
• Neglecting storage. Drums and jerrycans must be kept closed, labelled and away from other chemicals they could react with.

Frequently asked questions

What is the difference between a scale inhibitor and a descaler?

The scale inhibitor prevents limescale from forming, the descaler dissolves it when it is already there. They are often used one after the other.

How is the product dosed?

With a dosing pump or at the point indicated by the supplier, in the quantity derived from the water analysis. It must not be mixed with other chemicals.

Can I use a swimming pool product in an industrial system?

It depends on the system: chlorine and pH correctors are made for swimming pool and process water, not for boilers. For cooling circuits choose products indicated for that use, such as dispersant scale inhibitors.

Do I need protective equipment to handle it?

Yes: gloves and glasses at the very least. For strongly acid or alkaline products, read the safety data sheet.

Is the same product suitable for boiler and pool?

No. They are different uses, with different products: for boiler water you use oxygen scavengers and conditioners, for the pool chlorine and pH correctors.

You will find all products in the Water treatment collection: if you do not know which to choose, ask the AMES technicians for a quote or advice, with the water analysis data.