What is a Boiler?

The pressure vessels which are designed to heat water or produce steam can then be used to provide space heating and/or service water heating to a building, and are popularly known as boilers. 

The heating source in the boiler in most commercial building heating applications is a natural gas-fueled burner. Electric resistance heaters and oil-fired burners can also be used. In some applications, such as absorption cooling, kitchens, laundries, disinfect, and steam-driven machinery, steam is preferred over hot water.

There are many benefits to using Boilers which make them a very common & strengthening feature of commercial buildings. 

Controlled combustion of the fuel to heat water is used by both gas and oil-fired boilers. The key components involved in this process are the burner, combustion chamber, heat exchanger, and controls. 

 

Why exactly would you need retubing in these Boilers?

There are more than a few reasons as to why you would need retubing tools in your boilers, but some of the most common reasons are listed below.

Corrosion in Tubing 

Corrosion can produce pitting and a loss of integrity in the tubing. There are various explanations for this problem, including too much oxygen in the water and inappropriate standby boiler storage.

Inability to Pass A Hydrostatic Test 

To have an accurate understanding of the condition of the boiler, a hydrostatic test is required as visual inspection might not be enough. If the boiler fails the hydrostatic test, it indicates that retubing is required urgently.

Building up of Scales 

When hard water remains untreated, it can cause a mineral deposit on the outside of the tubing. If the buildup increases a lot, it can impede heat transfer, preventing the water from properly cooling the tubing. If the temperature increases too much, it can result in the tubing rupture or blowout. 

 

A Simple & to the Point Boiler Retubing Process!

The process of retubing in a boiler comes with many variations depending on the type of boiler in use. From start to end, there are a few steps that keep changing with different types of boilers. But, every boiler retubing process starts with a thorough inspection and ends with important & required documentation.

A Thorough Visual Inspection

You must begin by visually inspecting each boiler and performing NDT testing as needed. Dye penetrant testing is used to identify areas of boiler tube sheet cracking.

Boiler Tube Extraction

In this step of the boiler retubing process, old boiler tubes are removed along with the tube ends. Any minor tube sheet cracks are repaired when appearing to the ASME code specifications.

Installing A New Tube

After you have carefully extracted the faulty tube from the boiler, the next step asks you to install a brand new tube that is perfectly apt for your boiler. There are different methods of installing the tube into your boiler depending upon the type of boiler you own. You can either install it, roll it into the system, beaded, or sometimes welded in the hot pass.

Necessary Boiler Testing 

Now this stage requires you to hydro test the boiler. After this, the boiler is supposed to be closed and prepared to fire using all new gaskets. You have to visually check the scale and fit during this phase. You can also go for ultrasonic thickness testing, or boroscope the inside of water tube boiler tubes as required.

This is how you complete the retubing process of a boiler, while the installation method & extraction method of the tube depends on the type of boiler in use, the rest of the steps in this process stay the same throughout the world.