Resistance to corrosion, strength, durability, cost-effectiveness, fire retardancy and a low environmental impact are just some of the reasons why galvanised steel pipe systems have become one of the most popular choices in recent years.
A galvanised steel pipe is a steel pipe that has been coated in a layer of molten zinc, which ultimately protects the metal from becoming rusted and corroded rapidly and prevents the need for replacements in the short term.
This makes the system far more cost-effective, and because these systems are so versatile, it is relatively easy to perform upgrades and adjustments. When the time does eventually come to replace the pipes, the old ones can be recycled, meaning the environmental impact is kept to a minimum, a growing priority for many companies nowadays.
However, you can increase the lifespan of these pipework systems and delay the need to replace components by carrying out the necessary maintenance. The following piece will discuss some simple steps you can take to do that.
Be aware of how other metals can react with each other
Different metals have different nobilities, and when some come into contact with others, certain reactions can occur.
When brass and copper come into contact with a more noble metal in a humid environment, they will begin to corrode. However, if these metals come into contact with zinc – a less noble metal – in which galvanised steel pipes are coated, the less noble metal will corrode.
So, a key maintenance tip is to place an insulator between the galvanised steel pipe and the other metals to avoid contact and any consequences.
Watch the pH of the environment
Acids can cause the zinc coating on galvanised steel to disintegrate, which is why it’s essential to avoid exposing galvanised steel products to an environment where the pH is lower than 6 or higher than 12 for long periods. An environment where the pH is between 6.5 and 11.5 is optimal for increasing the longevity of the pipe’s lifespan.
Highly corrosive environments
One of the main reasons steel is galvanised in the first place is to help prevent corrosion, but some environments, such as highly polluted areas or coastal locations, are particularly harsh, and it will be difficult to prevent weathering. With the high concentration of sodium in the air in a marine environment, the zinc coating can become weakened, so experts suggest rinsing the pipes with potable water regularly and keeping the pipes covered to protect them from harsh rain and sun.
Storage of galvanised steel pipes
For galvanised steel products that are not currently in use, it’s vital to think about what conditions you are storing them in. Is the area damp or humid? Is there poor ventilation? These are all things that could damage the pipes’ coating, and before you have even used them, the clock is ticking on their zinc coating.
Keeping products in a dry, well-aired area is a key way to avoid this.
Repairing a galvanised steel pipe
If, for some reason, the coating on the pipe gets damaged, chipped or scraped, there are two main methods of repair. A zinc-rich paint, applied with a brush, is sometimes used to cover the affected area. The paint itself should state that when dried, it will contain at least 85% zinc and if applied correctly, this can be a very convenient repair method.
An alternative option is zinc metal spraying. This is a little more complicated as before the damaged area can be sprayed, it must be grit blasted to Class 3. Once this is done, the zinc spray can be applied, followed by an aluminum vinyl paint to seal the repair.
Cleaning a galvanised steel pipe
Do not take abrasive substances or aggressive cleaning tools to galvanised steelwork, which may damage the zinc coating and affect its performance. Start with more conservative cleaning methods using regular laundry, car or truck soaps and rinsing with a plentiful supply of pure water. Avoid the use of high-pressure washers or water sprayers if you can.
With more stubborn stains, you may need to aggravate them using a bristle brush, but you should always use a hard plastic brush for this, never a wired one, as it will damage the zinc coating on the pipe.
In a similar way, when it comes to paint or graffiti stains, you can use thinners on galvanised steel, but only with a wooden or plastic scraper, not a metallic one.
If the pipes are stained from water flowing from nearby rusted pipes, you may use a descaling solution or a commercial oxalic acid. The most important thing to keep in mind when attempting to clean a galvanised steel pipe or pipework system is to start mild and rinse whatever products you do use extremely thoroughly.
If you don’t, residues may remain on the surface which can impact the galvanisation and cause the pipe to deteriorate prematurely.