How to choose a corrugated compensator? The old driver will take you through it once

What is a ripple compensator? Is it the same thing as an expansion joint?

Don't be too long-winded, I get asked this question several times a day. Many people ask as soon as they come up, "What is the difference between corrugated compensator and expansion joint?" Actually, they are the same thing, just different names. Corrugated compensator, corrugated expansion joint, compensator-all refer to the same component that can absorb the thermal displacement of the pipe and reduce vibration and noise. Just remember:Corrugated compensator = expansion joint。 Don't be confused by the name when selecting the model. It is a serious business to look at the working conditions and parameters.

How to pick under different working conditions? Power station, cement, desulfurization, high temperature... Which kind is suitable for your pipeline?

Choosing a compensator is the same as picking shoes. Fit is the last word. Let's talk in a few common scenes:

• Power station industry: There are many high-temperature and high-pressure steam pipelines, so they can be usedCorrugated expansion joint for power station industry, orHigh temperature axial expansion joint。 If it is a vacuum pipe (like an air-cooled island), you have to ask outDouble hinge expansion joint for air-cooled island vacuum pipelineCan resist negative pressure.
• Cement industryLarge dust, large temperature fluctuation,Metal Corrugated Expansion Joints in Cement IndustryIt is standard, and the leather is durable. If the air duct diameter is particularly large,Metal rectangular expansion jointCan get on too.
• Desulfurization system: The flue gas contains sulfur and is highly corrosive, so it can be usedDesulfurization flue gas baffle doorPaired with a corrosion resistant compensator. At this timerubber compensatorOrPTFE-lined hoseMore built than pure metal.
• High temperature occasion: Temperature over 600°C? Ordinary stainless steel bellows are quickly scrapped. Directly onHigh temperature axial expansion jointOr considerNon-metallic expansion joint (fabric fiber expansion joint), temperature resistant and cheap.

Are there any universal models that can take all? Alas, stop dreaming. Each one is designed for specific working conditions. Such asUniversal corrugated expansion jointIt is suitable for normal temperature and low pressure, but it will be perforated after half a year in the desulfurization tower. Therefore, you must tell the manufacturer when selecting the model: temperature, pressure, medium and displacement are indispensable.

Some of the easiest places to roll over during installation

I met a customer two days ago, and it leaked after two months of installation. When I asked, the tie rod was not removed. You say it was wrong or not? Come on, note down the key points:

• Will the tie rod be removed or not?Many expansion joints come out of the factory with tie rod nuts, which is to prevent the bellows from being crushed during transportation and installation. But after installing it,The tie rod nut must be loosened or removedSo that the bellows can expand and contract freely. If you forget to loosen it, the compensator is equal to decoration, and the pipeline stress is all suppressed, and something will happen sooner or later. For specific adjustment, you can turn through the article "How to Adjust the Tie Rod Nut of the Expansion Joint" in our station.
• Where does the arrow point?There is usually an arrow on the expansion joint cylinder, which indicates the direction of the medium flow. What happens if you put it backwards? In the slightest case, the guide tube fails, and in the worst case, the bellows is washed and perforated. Remember:The direction of the arrow is consistent with the direction of the medium flow。
• What is the deflector used for?To put it bluntly, it is to protect the bellows from high-speed airflow or particles directly washing the wave crest. Especially for dusty flue gas pipelines, the life of expansion joints without guide tubes is directly cut in half. For the detailed principle, please see the "Specific Function of Expansion Joint Guide Tube" in the station.

Don't be lazy in routine maintenance, the life can last for several years

Many people think that they don't have to worry about the compensator when it is installed, which is a big mistake. Do a few things regularly: First, check the bellows surface for cracks and corrosion pits; Second, listen to whether there is any abnormal noise, maybe the internal guide tube is loose; Third, see if the tie rod nut loosens itself due to vibration (although it needs to be removed, some large tie rod expansion joints keep the tie rod as a limit, and the nut can't be completely loosened).

By the way, the gas bellows-the same hose that the gas stove at home connects to. The national standard is clearly written:It is recommended that the gas bellows be replaced every 2~3 years。 Why? Rubber seals will age, and bellows are afraid of rat bites. Don't try to save those dozens of dollars, the air leak is no joke. If you are not sure, look at the service life marked on the tube body.

When will the non-metal, rubber and PTFE compensator be available?

Don't just stare at the metal! In some cases, non-metal is more fragrant. Something like:

• Non-metallic expansion joints (fabric fiber expansion joints): High temperature resistance, corrosion resistance, and can also compensate for multi-dimensional displacement. Flue gas ducts and hot air ducts are particularly suitable. And the price is much cheaper than the metal one.
• rubber compensator: The vibration and noise reduction effect is first-class, and the inlet and outlet of the water pump are used more. The disadvantage is that the pressure and temperature resistance are limited, and do not exceed 80℃.
• PTFE compensator (lined with PTFE or pure PTFE): Almost any strong acid and alkali are not afraid, and chemical pipelines are the first choice. However, PTFE itself has poor rigidity and is usually made ofPTFE-lined hoseOrRubber PTFE compensatorBoth anti-corrosion and pressure-bearing.

highly corrosive upper tetrafluorine; High temperature flue gas is mostly non-metallic; Rubber on vibration and noise reduction. Of course, if it is a high-temperature and high-pressure steam pipeline, you have to honestly use metal corrugated expansion joints, such asStraight pipe pressure balanced expansion jointOrExternal pressure single axial expansion joint。

There is no universal formula for selecting a compensator, but if you find out the temperature, pressure, medium and displacement, and then correspond to the more than 20 models in our station, you will probably be right. If you are really unsure, just ask the manufacturer and don't pat your head yourself.