Friends who are power stations, cement and chemical industries ask the same question every once in a while: How many years can this flue expansion joint last? To be honest, I can't give a standard answer. Some people replace them in a year or two, while others still carry them after seven or eight years of use. What do you think is the difference? Today, let's break and break, and what things are pulling its life behind its back.
If the material is not selected correctly, the life will lose at the starting line
Think about it, the temperature in the flue is always hundreds of degrees, and the flue gas is still sulfur and corroded. Ordinary rubber compensators (such as the rubber compensator in our station) will definitely not hold it inside, and it will age and crack in a few days. At this time, non-metallic expansion joints (fabric fiber expansion joints) or high-temperature axial expansion joints are needed. Non-metallic fabric fiber layer is temperature-resistant and corrosion-resistant, and metal bellows are also particular: do you choose 304 or 316L? Or an alloy that is more resistant to high temperatures? It's not just about money, it directly determines how long you can use it.
For example, the desulfurization system of power station has low temperature but strong corrosion. With the desulfurization flue gas baffle door and non-metallic expansion joint, the service life can reach 5-8 years. If the picture is cheap and ordinary rubber is used, it may be perforated in half a year. Therefore, when selecting materials, don't just stare at the price, explain the working conditions and parameters clearly, and let the manufacturer help you match the most suitable model-for example, there are hot air pipes for the cement industry in our stationMetal Corrugated Expansion Joints in Cement Industry, and coping with high temperaturesHigh temperature axial expansion jointAll of them are the right medicine.
Working condition is the number one killer of life
Flue expansion joint not only has to endure high temperature smoke, but also pressure fluctuation, vibration and dust erosion. Have you noticed if there is any localized wear on the surface of the expansion joint? Dust is polished every day like sandpaper, and no matter how good the material is, it can't bear it. There is also the extra stress caused by the misalignment of the pipe during installation-the pipe is crooked, and the expansion joint is hard broken to work. Can the life not be halved?
In addition, is the deflector installed or not? As we said in the question and answer on the specific function of the expansion joint guide tube, the guide tube can guide the airflow and reduce erosion. If it is not installed, the bellows will be directly exposed to the airflow, and its life will be much worse. So when you do your inspection, look at these details more.
If the installation and maintenance are sloppy, no matter how good the product is, it will be useless
Two days ago, a customer told me that their new expansion joint leaked after three months of use. I asked him if the direction of the arrow was right? The direction of the arrow of the expansion joint refers to the flow direction of the medium. If it is installed backwards, it is equivalent to making it bear force in the opposite direction. Is the tie rod nut removed or not? How to adjust the expansion joint tie rod nut? Is pre-stretching done before installation? These are mentioned repeatedly in our FAQ-for example, does the screw of the expansion joint need to be removed? The answer is that the limit screw for transportation must be loosened or removed after installation, otherwise the expansion joint will not work.
Look for signs of deformation, cracking, leakage. Don't wait for something to happen before changing. At that time, downtime loss plus replacement labor is much more expensive than buying a good product. Think about it, is this the case?
Different application scenarios have different life expectancy
Don't expect a standard answer to win the world. The flue gas desulfurization system of power station, the temperature is not high but the corrosion is strong, and the desulfurization flue gas baffle door is matched with non-metal expansion joint, which can last 5-8 years after good maintenance. Hot air ducts in the cement industry, with a high temperature of several hundred degrees, can last for 3-5 years with metal corrugated expansion joints or high-temperature axial types in the cement industry. The flue of the chemical industry may contain acid and alkali, so it has to be lined with PTFE hose or PTFE compensator, which has better corrosion resistance.
What are my working conditions? Temperature, pressure, medium, vibration, installation deviation-give these parameters to the manufacturer, and they can recommend the best matching model for you.
Don't just focus on lifespan numbers, calculating the full lifecycle cost is more reliable
Cheap expansion joints are replaced every two years, good ones are used for a few more years, counting downtime losses and replacement labor, which is cost-effective? For example, if you choose a cheap rubber compensator and change it once every two years, you will lose tens of thousands of yuan every time it stops for half a day. After three years, the total cost may be higher than buying an expensive metal corrugated expansion joint directly.
When selecting the model, make the working condition parameters clear, and let the manufacturer match you with the most suitable model and material. This is the right way to prolong the life. The product information in our site, likeUniversal corrugated expansion joint、Straight pipe pressure balanced expansion joint、Compound hinge transverse expansion jointAnd so on, all designed for different scenarios. Don't choose by yourself, ask more manufacturers and avoid detours.
The service life of flue expansion joint is not a number, but a result-materials, working conditions, installation and maintenance, every link is achieved, and it will naturally last for a long time. The more you do, the longer it will pay you back for years.