4 Signs Your Factory's Old Cast Iron Water Pipes Need Replacing

If you are in charge of maintenance at an older factory, you may be responsible for the upkeep of the cast iron water pipes used to cool the equipment. Because of the iron's tendency to rust, you may worry that they may be deteriorating. If so, look for the following four signs that your factory's old cast iron water pipes are corroding and need replacing.

Corrosion around Brass Fittings

Although the pipes may be old and made from cast iron, the fittings connected to them are often made from brass. Also, bolts connecting the heavy-duty pipes may have been replaced with brass ones. If you have any brass fittings or bolts, look carefully at the iron adjacent to them for signs of corrosion. 

Since brass and iron are part of the same Galvanic Series, they are related and share electrons. Because brass has a higher number of electrons than iron, the flow of electrons from the brass to the iron causes electrolysis.

This constant electrical charge causes the iron to corrode and rust. Eventually, this leads to enough breakdown that causes holes to develop on the iron next to the brass.

If you see any major deterioration, the pipes should be replaced with a metal that is not affected by the phenomenon. The plumber can recommend the appropriate material if your company wants to continue using brass fittings.

Rusty Areas on the Outside of the Pipes

After examining the areas around brass fittings for corrosion, inspect the entire outer surface of the pipes for rust. Since oxidation eats away at iron, the rust could eventually eat through the metal and create a leaking hole.

If you see any rusty areas, check to see how deep the oxidation has gone by brushing the pipe with a steel brush. If the pipes only have surface rust, brushing the pipes should remove the layer of oxidized metal. If this is the case, you may be able to save the pipes from further rust by coating them several times a month with machine oil.

However, if you brush the rusted areas and damage has gone deeper than the surface, you may start seeing gouges in the metal. Also, the metal will start flaking off with every brushstroke. This is a sign that the rust has penetrated the pipes to the point that a leak may be imminent. These pipes should be replaced by an industrial plumber soon before this happens.

Water Becomes Reddish Brown

Whether or not you find areas of corrosion and rust on the outside of the pipes, you should also check to see if the inside walls of the pipes are starting to deteriorate. The easiest way to do this is to check the color of the water. 

If the constant flow of water through the pipes has started to corrode the interior walls, the rust will change the color of the water to a reddish brown. You may also see small flakes of oxidation and metal, depending on how badly the metal has deteriorated.

To check the color of the water, use the access spigot to fill a glass jar with water. Hold it up to the light to examine the color and check for sediment. If you see anything other than clear water, the pipes should be checked by a professional.

If you notice any or all of the signs above, the cast iron pipes in your factory most likely need to be replaced. Contact a contractor that offers industrial plumbing services to schedule an appointment for them to inspect the pipes to ascertain the extent of the damage. They can then discuss your options for replacing them with pipes made from newer, non-corrosive materials. For more information, contact companies like Cool Air Mechanical, Inc.