What is the difference between non-metallic expansion joints and rubber joints?
"That expansion joint on my desulfurization flue is cracked. Can you use a rubber joint to top it up first?" When I heard this, I quickly stopped it-brother, this is not to save trouble, but to dig a hole for myself. Non-metallic expansion jointsFabric fiber expansion joint) andrubber compensator(Commonly known as rubber joint), it does look a bit like it, and it is all soft connection. But the lining is far from it. One relies on multi-layered fabrics and metal frames to carry high-temperature smoke, and the other relies on rubber elastomers to absorb vibration and displacement. Today, I'll break the difference between the two and make it clear.
Let's see what they're all made of
Non-metallic expansion jointThe main body is a composite layer of silicone cloth and fluorine adhesive cloth, with stainless steel wire mesh sandwiched in the middle, and metal frame fixed on the outside. This thing can withstand 1000°C and higher-like oursThe high-temperature axial expansion joint is specialized in this. Whilerubber compensatorWhat? Pure rubber or cloth-sandwiched rubber, formed by vulcanization process. The highest temperature resistance is 100-200℃, and it will be soft, cracked and aged anymore. One is like armor, the other is like a rubber band — armor can block fire, rubber bands can only block small vibrations.
Performance data is put up, don't just feel it
Non-metallic expansion joints have a large amount of compensation, can absorb multi-directional displacement, and are especially suitable for rectangular pipes-at this time, they must be usedRectangular non-metallic expansion joint。 Rubber joints are better at vibration and noise reduction, but the pressure resistance is limited, generally PN0.6-1.6MPa. When encountering corrosive media, such as sulfur flue gas and acid-alkali solution, rubber joints are easy to age and crack. What about that? Can be usedRubber PTFE compensatorCome to the rescue, PTFE lining can carry corrosion, but the temperature resistance still can't keep up. In the final analysis, the selection depends on three numbers: temperature, medium and compensation direction. Whichever is wrong, something goes wrong in three months.
Exactly what scenario should it be used in?
Cement plants, flue ducts of power plants, boiler outlets-these places must use non-metallic expansion joints because of high temperature resistance, corrosion resistance and flexible structural compensation. OurDesulfurization flue gas baffle door、Electric plug-in insulation door、Manual plug-in insulation doorThese equipment interfaces are usually used with non-metallic expansion joints instead of rubber joints. In turn, the inlet and outlet of water pump, air conditioning pipeline, water treatment system-these places have low temperature, stable pressure, and mainly vibration isolation. Rubber compensator is suitable, which is cheap and easy to change. It is not impossible for you to install non-metallic expansion joints on the water pump, but the cost is high and the material is overused, so why bother?
Don't confuse the names, let alone the standards
Some peers call non-metallic expansion joints "fabric compensators" and rubber joints "rubber expansion joints", but they must not be mixed in function. Especially high-temperature dusty media-such as the flue gas at the outlet of power plant boilers, the temperature can reach above 800℃, and there is a lot of dust washing. Rubber joint up? It will crack in three months, and the ash is pasted to death. The non-metallic expansion joint is designed according to the national standard JB/T 12235-2015, multi-layer fabric + metal frame, much longer life. And guess what? In a previous project, the customer changed the rubber joint himself, and it leaked in less than half a year. The loss of shutdown was more expensive than buying ten non-metallic expansion joints. To summarize in one sentence: look at the temperature, the medium and the compensation direction. If you choose the wrong one, you will dig a hole for yourself.
One more word, our product line in our station is very complete- -Metal hose、PTFE-lined hose、Corrugated expansion joints(general purpose type, direct burial type, pressure balance type, hinge type...), andRound flapper door、Double-sealed single-axis circular baffle doorWait. If you are unsure of the specific working conditions, just throw the parameters over, and we will help you calculate according to JB/T standard. Don't guess for yourself, let alone use rubber joints to carry the flames — it really can't carry it.