Boilers – Frequently Asked Questions

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Frequently Asked Questions for Boiler Water Treatment:

Why do I have to chemically treat my boiler?

1) To prevent boiler scale
2) To minimize corrosion to the feedwater and steam & condensate system
3) Improve boiler efficiency.

What is boiler scale?

The most common scale is white in appearance and is from calcium carbonate that has precipitated from hard feedwater. Hard water contains calcium and magnesium and are minerals that are hard to wash. Silica scale is brittle and has a glass appearance. The most common scale is white in appearance and is from calcium carbonate that has precipitated from hard feedwater. Hard water contains calcium and magnesium and are minerals that are hard to wash. Silica scale is brittle and has a glass appearance.

Why is my feedwater tank leaking?

If your tank is leaking is it has been improperly treated for years. Make sure your sulfite is fed to the feedwater tank and that it is being feed though an injection quill that reaches near the center of the tank.

Why did my feedwater pump fail due to excessive corrosion?

If your feedwater pump has experience excessive corrosion and/or failure it is most likely from inadequate amount of sulfite being fed to the feedwater tank. Make sure your sulfite is fed to the feedwater tank and that it is being feed though an injection quill that reaches near the center of the tank.

What tests should I perform on my condensate system?
For those who have any inquiries concerning exactly where as well as the way to utilize new boilers, you possibly can e mail us with the web site.

Monitor:
1) Insoluble and soluble iron
2) Condensate pH (7.5-8.5 for most systems)at the furthest point from your boiler and possibly at multiple locations if your system is large.
3) Condensate corrosion coupons.

Why is my condensate pipes leaking or excessively corroding?

Corrosion occurs from carbonic acid and oxygen pitting. Carbonic acid occurs from CO2 which is a breakdown molecule of the carbonate alkalinity condensing from water to form H2CO3. Oxygen pitting occurs as steam condenses and the vacuum created pulls air into the condensate system.

What is hard water?

Hard water contains calcium and magnesium. These minerals are considered as hard to wash.

Why do I need a softener?

A softener is designed to remove calcium and magnesium from the “make-up” water.

What is boiler carryover?

If your boiler water suspended solids are excessive, some solids may collect on the surface of a steam bubble and exit the boiler with the steam.

Why do I need to feed a polymer or phosphate to my boiler?

Phosphate and polymers are required in boilers to prevent the calcium and magnesium from precipitating to the boiler tubes. Theoretically, some calcium and magnesium will leak though the softener. The calcium and magnesium minerals attach themselves to the polymer or phosphate and are discharged either through surface blowdown or during botto blowdowns.

What is a one drum program?

A one drum program is referred to as a chemical mixture that contains all the boiler chemical components (sulfite, amine, phosphate/polymer, and alkalinity) in one container.

What do I have to feed sulfite to my boiler?

Sulfite is referred to as an oxygen scavenger. Sulfite is the most commonly used oxygen scavenger. It is used to remove the water’s dissolved oxygen.

How do I calculate how much condensate I am returning?

To calculate your return condensate percentage multiply 100 by 1-(feedwater silica/makeup water silica)

What is boiler blowdown?

Blowdown is the removal of the concentrated dissolved and suspended solids. By blowing down the system, lower concentrated water dilutes the existing water in the boiler.

How much do I need to blowdown my boiler?

It depends on how many impurities you have in your feedwater. The goal is to determine what the limiting factor is (dissolved solids, alkalinity, silica, or iron) in your boiler water and set your blowdown setting at that limit. To determine the amount of blowdown percentage divide 1 by your concentration ratio and multiply by 100.

Why is my boiler water red?

If your boiler water is red in appearance, it may be from a number of possible reasons. Some of the most common ones are:

1) Inadequate levels of sulfite
2) Over feeding your alkalinity
3) Condensate contamination
4) Overfeeding an acidic sulfite product that depresses the boiler water pH
5) Low alkalinity

Why is my boiler scale only on my bottom tubes?

If you have poor performing softeners, if your softeners are being by-passed, or if you do not have softeners “hard water” is entering the boiler. Remember phosphates and polymers are only used as “polishers” to remove the minimal amounts of Calcium and magnesium that enter the boiler. Your pre-treatment is designed to remove 95% of the calcium and magnesium. If you are using a straight phosphate program with no polymer, make sure to perform bottom blowdown twice a day. A phosphate chemical is designed to sink to the boiler bottom after the calcium and magnesium is attached.

What is a deaerator?

A deaerator is mechanical way of removing dissolved oxygen from the water. There are different types of deaerators and multiple manufactures. Remember you still need to feed an oxygen scavenger to remove the dissolved oxygen that the deaerator does not remove.

What boiler tests should I perform?

If you do not have man power or time to perform a bunch of tests. We recommend testing at minimum the boiler water sulfite residual, boiler water conductivity, and feedwater/softener hardness. Also, we recommend monitoring your chemical inventory daily as a double check to ensure sufficient chemical is being added to the chemical.

What is the boiler chemical amine?

There are two main categories of amines, neutralizing amines and filming amines. Neutralizing amines are the most common. Amines are designed to increase the condensate pH to minimize condensate corrosion. Make sure to check how your steam is being used. In some applications, there may be restrictions on using amines.

What items are common boiler failures?

1) Oxygen Pitting
2) Short-Term Overheating
3) Long-Term Overheating
4) Caustic Gouging

What is the boiler temperature of water?

The boiling point of water depends on pressure. At atmospheric pressure, water boils at 100C. As pressure increases, the boiling point increases. At 22,000 kPa, where water is converted to steam, the boiler point is lowered.

What is boiler feedwater?

Boiler feedwater is referred to as the water entering the boiler. It is a mixture of returned condensate and fresh make-up water.

Why do I have to return my condensate?

Condensate is hotter then make-up water and it contains valuable BTUs. The warmer the feedwater in the tank, the less energy you need to heat the water to make steam. So it is important to return as much condensate as possible.

What is boiler make-up water?

Make-up water is referred to as the fresh water that is added to the feedwater tank.

What is cycles of concentration?

Cycles of Concentration is refers to how many times you reuse your water. The purpose of a boiler is to reuse water. To calculate your cycles of concentration divide your boiler water silica residual by your feedwater silica.

How do I remove boiler scale?

One solution is to hire an outside company that specializes in acid cleaning. If scale is light, do not remove the scale, just make sure your softeners are functioning properly and use a polymer designed for gradual scale remove.

How do I prevent boiler scale?

1) Have a good operating softener
2) Make sure the brine tanks is half filled with salt at all times.
3) Perform softener hardness and feedwater checks daily.
4) If using a phosphate chemical program blowdown the boiler two times a day.

Where do I feed my chemicals?

Sulfite and alkalinity to the feedwater tank or drop leg of a Deaerator. Phosphate / Polymer to the feedwater line or drop leg of a Deaerator. Amine preferred to the steam header, but you can feed it to the feedwater line or drop leg of a Deaerator. One drum program or day tank to the feedwater line or drop leg of a Deaerator.

How do I feed my chemicals?

Preferably neat (straight from the drum). It provides a more consistent chemical dilution.

How do I wet lay up a boiler?

If you plan on keeping your boiler idle for more than a month, dry lay-up is the preferred method. If the boiler needs to be readily available to service. Add additional sulfite and alkalinity (if you are using an acidic sulfite) to the boiler. Maintain at least 100ppm of sulfite and check sulfite residuals weekly. Also, it is important to ensure the boiler tubes stay fully emerge in the water to prevent tube corrosion.

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