Why would anyone ask this kind of question?
To put it bluntly, in everyone's impression, non-metallic compensators (that is, non-metallic expansion joints) are used for hot air and flue gas pipes-such as flues of power stations and cement plants. The temperature is high, the medium is dirty, and the metal bellows can't bear corrosion, so they use compensators made of fabric fiber or rubber. But as soon as I arrived at the water system, hey, the master on the construction site muttered: Can this cloth skin bag be soaked in water? So, "Can non-metallic compensators run water?" This question is asked every three days. The answer? It's not as simple as you think.
First see what kind of "non-metal" you have in your hand
Don't rush to answer "can" or "can't", first distinguish what kind of non-metallic compensator you have in your hand. We have a product on our site calledNon-metallic expansion joint (fabric fiber expansion joint)The main body is multi-layer fabric + silicone/fluoroadhesive coating. The original intention of the design is to resist high temperatures and corrosive gases, but it is not resistant to long-term water immersion-water molecules will penetrate into the fiber layer, resulting in delamination, bulging and even tearing. But if you switch torubber compensatorOrRubber PTFE compensatorThe rubber compound itself is waterproof. EspeciallyPTFE compensator, acid and alkali resistant, water resistant, circulating water is completely fine. So the question is not whether "non-metal" will work, but whether the specific material and structure will work.
You put the fabric fiber expansion joint on the cooling water pipe. Within three months, water begins to drip on the edge of the flange. When you remove it, the inner fabric is completely soaked. However, in the same working condition, it is normal to use a rubber compensator for two or three years. Is that the truth?
Focus on three hard indicators when running water: pressure, temperature and media corrosiveness
Let's talk about the pressure first-the design pressure of non-metallic compensators is generally low, most of which are between 0.1~0.6MPa. If you use it to connect the water pump outlet to make a pressure of 2kg (about 0.2MPa), it depends on the parameters given by the manufacturer. The rubber compensator can usually reach 0.6~1.0MPa, but the fabric fiber is suspended. Talk about the temperature. Generally, the temperature resistance of rubber does not exceed 120℃, and fluororubber can reach 200℃. However, it is common in water systems that the room temperature reaches 80℃, which basically can withstand it. Finally, it is corrosive. Pure water is fine. Wastewater containing chloride ions or acid and alkali has to be lined with PTFE or special rubber. For example, desulfurization wastewater pipelines are sometimes usedRubber PTFE compensatorBecause it is resistant to both dilute sulfuric acid and abrasion.
Speaking of which, two days ago, I met a friend who did HVAC and wanted to install a non-metallic compensator for the air conditioning cooling water pipe, on the grounds that the metal bellows was too expensive. I poured cold water directly: the temperature difference of the cooling water pipe is not big, the displacement is small, and a single ball rubber compensator is completely enough, but if you buy an ordinary fabric fiber non-metallic expansion joint, it will leak in less than three months. He asked back, "That websiteRectangular non-metallic expansion joint"Can I walk away?" — — Rectangles are usually used with flues. If you have to use them at the inlet and outlet of the water tank, it is not impossible, but you have to customize the rubber layer, otherwise the weight of the fabric will double after absorbing water, and the flange bolts will be too much to bear.
Can you run water or not?
In the final analysis, whether a non-metallic compensator can "run water" depends on what kind of "non-metallic" it is. For rubber and tetrafluorine, running water is one of my jobs (provided that the pressure and temperature match); For fabric fibers, try not to touch water. If you really want to use it, you must communicate with the manufacturer to make waterproof lining. Don't pat yourself on the head. If you choose the wrong choice, you can leak and shut down, or the whole pipeline system will suffer.
If you're not sure, just go to the one on our stationrubber compensatorAndPTFE compensatorPage, or make a phone call and ask about technology, is much more reliable than guessing. After all, spending a few minutes figuring it out is more cost-effective than spending thousands on equipment, isn't it?