Find out first: What's the matter with adding fluorine glue to non-metallic compensators?
To put it bluntly, the non-metallic compensator we often call (also called fabric fiber expansion joint) is mainly made of soft materials such as glass fiber and silicone cloth, which is specially used to absorb the thermal expansion and contraction of pipelines or the vibration of equipment. However, in some working conditions, the medium is corrosive and the temperature is high, so ordinary silicone cloth can't bear it. At this time, fluororubber (FKM) is used in the inner layer of the ring belt or vulcanized as a whole, so as to make a "fluororubber integrated" structure.
Note that this is different from the "rubber PTFE compensator" in the station-PTFE is polytetrafluoroethylene, which is more anti-stick and resistant to strong acids; Fluorine rubber is fluorine rubber, which is mainly resistant to high temperatures and oil. The "non-metallic expansion joint (fabric fiber expansion joint)" and "rubber compensator" of this site can be customized with fluorine rubber lining according to customers' needs. Think about it, ordinary silicone cloth starts to become sticky and soft at 150℃. What about fluorine glue? It can still work steadily at 200℃, and it can be carried to 300℃ for a short time without cowardice.
The hard strength of fluorine glue: temperature resistance and corrosion resistance, doubling the life
I have seen many customers complain that ordinary non-metallic compensators age and crack after half a year's use. When the medium is checked, there is sulfide or high-temperature steam. The advantage of fluorine rubber is this: fluorine rubber can work at 200℃-250℃ for a long time, and it can reach 300℃ in a short time, which is much higher than ordinary silicone rubber (generally 150℃). Moreover, it has particularly strong tolerance to strong acids, strong alkali and organic solvents, and the desulfurization flue gas of power plants and corrosive waste gas of chemical plants basically do not need to be replaced frequently with fluorine glue.
Two days ago, I met a customer who made an incinerator. I used to use an ordinary non-metallic ring belt, which was changed once every three months; After replacing it with fluorine glue, there was no problem for two years. It saves more than half of maintenance costs. Tsk, do you think this thing is worry-free?
Where must it be? Application scenarios and selection contraindications
First, the desulfurization system of coal-fired power plant, the pipeline behind the flue gas baffle door, the temperature, humidity and corrosiveness exist at the same time-the "desulfurization flue gas baffle door" of this station is a perfect match with fluorine glue compensator. Second, the catalytic cracking unit of petrochemical industry, high-temperature oil and gas contains sulfur. Third, the smoke exhaust pipeline of the waste incineration plant.
Although fluorine glue is oil-resistant, it will swell against ketone and ester solvents (such as acetone). Be sure to confirm the media composition before selecting. In addition, if the "rectangular non-metallic expansion joint" in the station needs to be integrated with fluorine rubber, the flange connection size and bolt hole distance should be communicated in advance, so that it can't be installed on the spot. What about that? Provide media composition list and pipe layout diagram, and our technology will help you calculate directly.
Pits that are easy to step on during installation: guiding, pre-tensioning and bolt torque
Fluorine rubber integral parts have good elasticity, but if the installation is not standardized, it will still be wasted. First Pit: No pipe guide brackets are set. The non-metallic compensator can only absorb axial and angular displacement, and cannot bear the self-weight of the pipeline. It is necessary to ensure that the pipeline has guide brackets at both ends of the compensator. Pit 2: Forgot about pre-stretching. Many installers don't understand it, so they install it directly. As a result, the fluorine rubber ring belt is in a relaxed state when it is cold, and it will tear when the temperature rises.
According to the designed compensation amount, compress the compensator to the pre-stretched position with a screw during installation, and loosen it after the pipe heats up. The third pit: the bolts are tightened too tightly. The flange surface of the fluorine ring needs to be evenly compressed, and the torque should be controlled at about 80% of the recommended value. Pay special attention to aluminum-magnesium alloy flanges-it's too late to cry after twisting the slip wire.
The maintenance cycle is different from that of ordinary compensator
Don't wait until it leaks before replacing the fluorine rubber integrated ring belt. It is recommended to check the outer surface for cracks every six months, paying special attention to the roots in contact with the flange – where the stress concentration zone is. In addition, when the medium contains particulate matter, a layer of wear-resistant lining can be added on the inside of the ring belt, and the "non-metallic expansion joint" of this station can be reinforced with 316L stainless steel wire mesh.
Fluororubber will harden at low temperature. Start after parking in northern winter, preheat and then open the valve to avoid instantaneous stress impact. And guess what? Some customers opened the valve directly in winter, and the root of the ring belt cracked on the spot. It cost several thousand to change it. Lesson ah.