When many people get a non-metallic compensator, their first reaction is: Should this thing be welded to the pipe or flanged? Alas, it's not that simple. Non-metallic compensators- -what we often call fabric-fiber expansion joints or rubber compensators- -are connected to more than just a random tube. It is born to deal with air duct, flue, dust collector inlet and outlet, fan interface and even boiler wall mouth. Think about it, the temperature of the flue on the other side of the desulfurization tower of the power plant has soared from normal temperature to 180℃, and there is still sulfuric acid mist sandwiched in the medium, which is frighteningly corrosive. The non-metallic compensator is carried by its layer of flexible fabric and rubber, so the connecting end is either a steel flange paired with a pipe flange, or it is fixed directly to the equipment housing by beading and bolting. If you are in the wrong position, thermal expansion and contraction, air leakage, tearing or even bursting pipe, you can't run from either.
There are three ways to connect, but there are many pits
The mainstream connection methods are not flange connection, welding connection, and quick coupling with sleeve and clamp. Flange connections are the most common, especially large-diameter rectangular non-metallic expansion joints, such as oursRectangular non-metallic expansion jointOrNon-metallic expansion joint (fabric fiber expansion joint)When you leave the factory, you will be equipped with flange surfaces at both ends, and you can directly match holes and screw bolts with the equipment flange on the spot. But there is a pit you pay attention to: the sealing gasket on the flange surface must not be too hard. The non-metallic compensator itself is soft, but when the gasket is hard, it will strangle the compensator, and the seal surface will press out marks. It is a matter of time before air leaks.
What about welding? Generally used in high pressure or high temperature applications, such asHigh temperature axial expansion jointWhen butting metal pipes, the welding should take into account the deformation of the heat affected zone. After welding, the inside and outside of the compensator have to be cleaned up. If the welding slag splash collapses onto the fabric layer, it will be a hole. As for the quick coupling-don't laugh,rubber compensatorAndRubber PTFE compensatorThis is often used on small-diameter pipelines, and the chemical line can be installed in one hour during emergency repair, saving time and effort. But if you take it to the big flue, the clamp won't hold up.
Don't confuse it with metal hoses and corrugated expansion joints
What is the difference between non-metal compensator and metal hose or corrugated expansion joint? In fact, the device side they are connected to is very different. Metal hoses usually have live joints at both ends, which are connected to rotating equipment such as water pumps and compressors, mainly absorbing vibration displacement; The non-metal compensator is connected to a large air duct and flue duct. Such asMetal Corrugated Expansion Joints in Cement IndustryAnd the non-metallic compensators used in the cement industry, although they all carry high temperatures, the non-metallic fabric can withstand greater lateral displacement and angular displacement, which is suitable for pipeline corners or places with limited space. If you use them backwards-the metal hose is forced into the flue, and it will crack in less than three months. In turn, the non-metallic compensator is connected to the high-pressure liquid pipeline? That was even more seeking death, and the pressure would immediately rise.
Connect with the baffle door, the order should not be chaotic
Let's talk about another case of frequent rollovers-the connection to the baffle door. Our products haveFlue gas baffle door、Double-sealed single-axis circular baffle doorAndManual plug-in insulation doorThese baffle doors are often installed in series with non-metallic compensators. For example, the inlet of the desulfurization system of the power plant is first connected to a non-metallic compensator to absorb the heat displacement, and then connected to the baffle door to cut off the airflow. The installation order cannot be messed up! The compensator must be installed upstream of the baffle door (according to the direction of medium flow), otherwise the impact force generated when the baffle door is closed will directly hit the compensator, and the sealing layer will be degummed in minutes. In addition, when the rectangular non-metallic expansion joint is docked with the circular baffle door, a square and circular reducer has to be added in the middle. This detailed drawing often misses the mark, and it is found that it can't be installed during on-site construction-guess what? Only temporarily let the manufacturer rush to change the diameter, and the construction period is so delayed.
Connection calculation in the selection stage is the big job
The connection size of non-metallic compensator should not only look at the nominal diameter of the pipe, but also include the displacement. For example, the temperature of the desulfurization flue of a power plant rises from normal temperature to 180℃, and the expansion of the main pipe is calculated to be 80mm. When you choose the compensator, you have to make it connect the flange on one side to reserve enough axial compensation space, otherwise the bolts are tightened, the compensator has no place to stretch, and the deadlift can't be pulled. And the pressing device-ourHow to adjust the tie rod nut of expansion joint？ Many workers screw to death directly, feeling that the tighter it is, the less it leaks. Wrong, actually. The function of the tie rod of the non-metallic compensator is to limit the over-displacement. After installation, it should be loosened to the design value to leave the movement margin. Screwing to death is equivalent to welding the compensator to death, so what is the compensation? When thermal expansion and cold contraction come, the force is all held on the flange, and the bolts have to collapse.
Finally, a practical suggestion
If you're not sure what the non-metallic compensator is safest to connect to, don't guess. Send all the working condition parameters (medium, temperature, pressure, pipeline material, corrosion or absence) to the manufacturer, and let them produce the connection structure diagram. Remember one principle-the equipment or pipe connected to both ends of the non-metallic compensator must be rigidly fixed, and the compensator must not be used as a support. Otherwise, when the vibration comes, it will be a matter of time before the joint tears. In the product catalog you have, whether it isCorrugated expansion joint for power station industryStillDesulfurization flue gas baffle doorThe design of the connecting end is particular, just install it according to the drawings. Don't be too troublesome. There is an air leak accident at the scene, and the maintenance cost is enough for you to buy ten compensators.