Specialized in manufacturing compensators, expansion joints, baffle doors

What the hell are fixed rods on non-metallic compensators for? Don't wait until the equipment breaks

Although it is called "non-metal", in fact, the skeleton and fixtures are still inseparable from metal. Many people thought that the bright fixed rod was used for lifting or convenient transportation-two days ago, a customer asked me if this thing could be removed, and I thought it was in the way. Disassembled? You try to disassemble it. As soon as the pipe heats up, the compensator will directly blow you into a balloon. The role of the fixed rod is far more important than you think.

The core task of the fixed rod is one word: limit

Limit excessive tension or compression of the non-metallic compensator in the axial direction (i.e. along the pipe direction). The non-metal loop strap itself is soft and elastic, but it can't stand hard tugging. When the pipe is displaced by thermal expansion and contraction, the compensator should absorb this displacement, but if the displacement exceeds the design value, the ring belt will be torn or folded. The retaining bar acts like a seat belt, telling you: At most you can run this far, and it will be dangerous further forward. In fact, both ends of the fixed rod are connected with connecting pipes or flanges, and a preset installation length is locked by a nut to ensure that the compensator works within a predetermined stroke range.

What's the difference between it and the tie rod on the expansion joint? That's a good question. Tie rods are usually used for metal corrugated expansion joints (such as the general corrugated expansion joints and compound hinge transverse expansion joints in our station). Its main function is to bear the blind plate force generated by internal pressure and prevent the bellows from being crushed to death by axial thrust. The fixed rod of the non-metal compensator is more to bear external loads and limit excessive displacement. In terms of material, the fixed rod of non-metallic compensator is generally made of carbon steel or stainless steel, and the surface is anti-corrosion treated. After all, the supporting flue gas and dust environment is often very harsh-such as the "flue gas baffle door" and "rectangular non-metallic expansion joint" in our product list, which are often used in desulfurization and dust removal pipelines. When corrosive gas rushes, if the pole rusts, the strength will drop, and something will happen.

How to judge if the fixed rod is adjusted properly?

Our product information mentioned the question and answer of "How to adjust the tie rod nut of the expansion joint". Although it is a tie rod, the adjustment logic of the fixed rod is similar. The core parameter is the mounting length-this length must correspond to the free length of the compensator in the cold state. For example, the working temperature of the pipeline is 300℃. When it is installed in a cold state, the fixed rod should be artificially compressed or stretched to a certain amount, leaving a margin for thermal displacement. You fit too tightly, there's no room to stretch when it's hot; Loaded too loosely, the loop straps sag when cold. Many on-site failures, nine times out of ten, are that the nut of this pole is not screwed correctly.

Another real case. A non-metallic compensator is connected in parallel next to our "metal corrugated expansion joint in cement industry" used in a cement factory to absorb the vertical displacement. On-site workers suspected that the fixed pole was in the way, so they dismantled it privately. Results After half a year of operation, the non-metallic ring belt was partially torn and the air leakage was serious. Change the ring belt and shut down for two days, resulting in hundreds of thousands of losses. Later, when the engineer checked, it was the lack of fixed rods that caused the deflection displacement to exceed the standard. Think about it, a pole costs hundreds of dollars, and a circle belt costs tens of thousands of dollars. This account is not unknown.

Finally, let's be honest

When selecting, don't just stare at the material and temperature resistance grade of the ring belt. The design and material of the fixed rod should also be checked. Especially for large-size rectangular non-metallic expansion joints, pole cross-section, thread specifications, and the strength of connecting ear plates at both ends have to be calculated. If you are not sure, read directly the article "National Standard for Non-metallic Expansion Joints JB/T 12235-2015" in our station, which clearly states the requirements for structural parts. With this pole, the compensator really locks the safety bottom line.

1. What material is the non-metallic compensator made of? Let's start with the conclusion: Not all non-metals are afraid of fire

When many people hear the word "non-metal", they automatically associate "plastic", "rubber" and "flammable" in their minds. This idea needs to be corrected quickly. Non-metallic compensator-to be precise, the one on our websiteNon-metallic expansion joint (fabric fiber expansion joint)— — The main material is a composite layer of high-strength glass fiber cloth, silicone rubber coated cloth and polytetrafluoroethylene film. Glass fiber itself is a Grade A non-combustible material with a melting point of more than 1000°C. What is really likely to burn is the rubber coating on the surface or the PTFE for sealing-but neither is at once. Silicone rubber is a flame-retardant material, which extinguishes itself from fire; Polytetrafluoroethylene (PTFE) is virtually nonflammable and only breaks down toxic gases in extreme heat. Therefore, the answer to the question "Can a non-metallic compensator catch fire?" depends on where it is used, at what temperature, and what medium it contacts. Think about it, if the material itself could be burned, then the thousands of degrees of smoke in the flue of the power plant would have set it on fire long ago, and it would have lasted for decades?

Second, under which working conditions the non-metallic compensator may indeed burn? Don't take any chances, these cases are worth watching

Seriously, the most common fire scenario for non-metallic compensators is the flue gas duct. For example, desulfurization system, cement kiln tail, power station flue and other places. The smoke often carries unburned sparks, oil mist or pulverized coal. Two days ago, a customer from a cement factory called and asked,Rectangular non-metallic expansion jointWill it burn through? I asked him if there were any sparks in the pipes and he said that the electrostatic precipitator occasionally ignites. This is dangerous. Once the surface coating of the fabric is continuously burned by high-temperature sparks, the silicone rubber will carbonize. Then, although the glass fiber cloth does not burn, it loses its sealing performance, the smoke leaks out, the temperature is higher, and finally the whole compensator will be scrapped. Another situation is that there is a leakage of flammable media in the pipeline. For example, the tail gas of chemical plants contains benzene steam, which may ignite when it touches high-temperature surfaces. Remember one sentence: the non-metallic compensator is not a source of fire itself, but it is a "carrier of combustion support"-if its surface is stained with oil and coal tar, it is equivalent to providing fuel for the fire. And guess what? At the end of many fire accidents, they were not burned by the compensator itself, but the ash and oil accumulated around them were ignited.

3. How do manufacturers prevent fires? Flame retardant coating, multi-layer structure, plus explosion-proof layer

Since there are risks, regular manufacturers must have countermeasures. When we make non-metallic expansion joints, we will select materials according to the medium temperature and composition provided by customers. For high-temperature flue gas pipelines (above 400℃), the structure of "ceramic fiber cloth + stainless steel wire mesh reinforced layer" is generally adopted. The refractory temperature of ceramic fiber can reach 1260℃, and it is okay to directly fight the flame. In the case of spark shock, the non-metallic compensator will be covered with a metal protective net or a metal skin-this is actually a bit like the one on our websiteHigh temperature axial expansion jointThe idea is that the high-temperature axial type is pure metal, and the non-metal type is only used as an inner liner. In addition, fluororubber or PTFE coating itself has good flame retardancy, which meets the fire protection requirements in JB/T 12235-2015 standard. Another point: when installing, it is necessary to ensure that no combustible materials, such as oil rags and cables, accumulate around the compensator. This is a problem of on-site management, but many accidents are precisely here. We often tell customers: You bought a fireproof compensator, and as a result, there is a pile of pulverized coal piled around, which is the same as not buying it.

Fourth, the easiest pit for users to step on: confusing rubber compensator and fabric compensator

We have a product list on our siterubber compensatorAndRubber PTFE compensator, there are alsoNon-metallic expansion joint (fabric fiber expansion joint)。 Although they are all classified as non-metals, the temperature resistance grade is much worse. The continuous working temperature of ordinary rubber compensators (such as nitrile rubber and neoprene rubber) generally does not exceed 120℃, and the instantaneous temperature resistance may reach 150℃. Beyond this temperature, the rubber will soften, decompose and even burn. However, the temperature resistance range of fabric fiber expansion joint (non-metallic expansion joint) is usually between 200℃ and 650℃, and it can be higher if the right model is selected. Therefore, if the user uses a fabric compensator in low-temperature pipelines (such as air-conditioning water systems), it is overqualified; But if a pure rubber compensator is used on a steam pipe at 300℃, it is a joke with your life. Before, a customer consulted, saying that the temperature of their flue gas pipe was only 180℃, and they used a rubber PTFE compensator. As a result, it burned through half a year later. Only after asking did I know that the actual temperature fluctuation peak of the pipeline reached 220℃, and the rubber layer had been carbonized. Therefore, when selecting the model, you can't only look at the average value, but also the peak temperature, duration and whether there are sparks in the medium. Is that the case?

5. Fire prevention starts from type selection: collect these three hard indicators

First, it is necessary to clarify the maximum operating temperature, instantaneous overtemperature temperature and frequency of the pipeline. If it is smoke with Mars, skip the rubber directly, choose a fabric fiber compensator and add a metal explosion-proof layer. Second, see if the compensator has flame retardant certification. The national standard JB/T 12235-2015 has clear requirements for the combustion performance of non-metallic expansion joints, such as oxygen index and horizontal combustion grade. On our stationRectangular non-metallic expansion jointAndNon-metallic expansion joint (fabric fiber expansion joint)Proof of flame retardant rating can be provided on demand. Third, don't ignore the installation environment. If the compensator is installed outdoors or has corrosive gases, the surface coating will age and the flame retardancy will decrease, requiring regular inspection and replacement. To put it bluntly, the deciding factor in whether a non-metallic compensator can catch fire is not whether there is "non-metallic" in the name, but whether you have put the right product in the right place. Choose right, it can hold thousands of degrees of high temperature; If you choose the wrong one, tens of degrees of oil fume can light it.

Let's ask a question first: Why use non-metallic ones if the pipeline is equipped with metal compensators?

Friends who have been in contact with power plants and cement plants know that metal parts can't bear corrosion and dust accumulation in high-temperature flue gas pipelines and desulfurization systems. Although the metal bellows has high strength, it will rust out in a few months when it encounters acidic medium and wet smoke. Non-metallic compensators use fabric fibers, rubber, PTFE and other materials to deal with these "soft knives". This site'sNon-metallic expansion joint (fabric fiber expansion joint)Andrubber compensatorIt is to make up for the shortcomings of metal parts-to put it bluntly, it is to wear a layer of "body armor" on the pipeline.

The structure is actually not complicated

A flexible loop strap, plus flanges, frame and insulation. The band material may be silicone cloth, fluororubber,PTFE (rubber PTFE compensator)。 The key lies in design: how can it be resistant to both temperature and pressure? Generally, multi-layer composite, inner layer insulation, outer layer sealing. Two days ago, a customer asked: YouRectangular non-metallic expansion jointDifference from round? To put it bluntly, rectangles are mainly used in square pipes such as smoke ducts, which have large compensation and convenient installation-and the four corners of rectangular pipes are prone to stress concentration, which can be digested by the flexibility of non-metals.

Function Article 1: Absorb multidimensional displacement

During thermal expansion and contraction, the pipe will expand and contract axially, yaw laterally and even twist angularly. Because of its flexibility, the non-metallic compensator can absorb the displacement in these directions at the same time, and is not afraid of twisting like metal bellows. Like those used in the cement industryMetal Corrugated Expansion Joints in Cement IndustryAlthough it can also be compensated, when encountering large rectangular flues, non-metallic rectangular expansion joints are more cost-saving and easier to maintain. Think about it, when the temperature of a flue dozens of meters long changes, the displacement is often more than ten millimeters or even tens of millimeters, and the metal parts will get stuck directly if they are not properly designed. The non-metallic band is like a "soft joint", which is not afraid of twisting.

Function 2: Carry high temperature, carry corrosion, and reduce noise

The pipeline behind the desulfurization flue gas baffle door of the power plant is not high in temperature, but the acid corrosion is serious, and the metal parts will rust through in a few months. useNon-metallic expansion joints (fabric fiber expansion joints)With PTFE lining, the life can be extended by two or three years. In addition, it has a vibration damping effect-the vibration of the fan is transmitted to the pipeline, and the non-metallic band can eat some energy, and the noise is low. Some data show that under the same working conditions, the non-metallic compensator can reduce the noise of pipeline system by 8~12 dB. Tsk, this thing is easier than a silencer.

Compared with metal compensators, what are the advantages of non-metal?

Low pressure capacity, cannot be used in high pressure steam pipeline. Moreover, non-metallic materials will age, and their life span generally has to be replaced after 3-5 years. What about that? Calculate clearly when selecting: the medium temperature exceeds 600℃ or the pressure exceeds 0.1MPa, and honestly use metal parts orHigh temperature axial expansion joint； Low temperature and low pressure, large diameter, corrosive media, non-metal is the first choice. Is that the truth?

Finally, a reminder of the main points of purchasing

The national standard JB/T 12235-2015 stipulates the technical requirements of non-metallic expansion joints, mainly depending on the material of the ring belt, compensation amount and connection mode. Pay attention to the direction of the guide tube during installation-refer to the Q&AArrow direction of expansion jointThe tie rod nut should be adjusted according to the on-site displacement, and do not screw it (see for detailsHow to adjust the tie rod nut of expansion joint）。 If you are not sure, you can compare this siteUniversal corrugated expansion jointAndRectangular non-metallic expansion jointProduct parameters, or just ask the technology – they have more experience than me.

In summary, the role of a universal non-metallic compensator? It is to solve the "difficult and complicated diseases" that metal compensators can't handle: high-temperature corrosion, multi-dimensional displacement, large-diameter special-shaped pipes, vibration and noise reduction. If you choose the right one, the equipment is worry-free; Wrong choice, post-maintenance is enough for you to drink a pot.

1. What exactly is the "welding non-metallic compensator" you asked? — — Clarify the concept first, don't buy the wrong goods

Two days ago, a purchaser called and asked "welding non-metallic compensator". I was stunned for half a second and asked him: By "welding" do you mean welding a non-metallic compensator to a pipe? Or does it mean that the compensator itself has metal welds? The other end of the line was dumbfounded. This thing is often called a bastard in the industry. Today, let's talk about it all at once.

The so-called "welded non-metallic compensator" actually refers to one with metal connectors (such as flanges or stub) at both ends, which is connected to the pipe by weldingNon-metallic expansion joint— That is what we often sayNon-metallic expansion joint (fabric fiber expansion joint)、rubber compensatorOrRubber PTFE compensator。 Its main body is a non-metallic loop band (fabric, rubber, PTFE, etc.), but the ports are usually made of carbon steel or stainless steel for the purpose of welding. So the name itself is a bit "contradictory", but everyone in the industry knows it: it means "non-metallic compensator with welded structure at the port".

Don't underestimate this definition. I have seen people buy pure rubber joints (looper flanges at both ends) and take them for flue welding. As a result, when they are baked at high temperature, the rubber melts away directly. Is it a waste of cost? So figure out that "welding" refers to the port structure, not the whole product is metal.

Second, according to the structure: rectangular and circular, the welding method is very different, rectangular non-metallic expansion joint is the main force

Rectangular and circular. The welding processes of the two are far from each other, and they can't be installed directly if they are selected incorrectly.

1. Circular welded non-metallic compensator

It is more common in pipeline systems, such as smoke air ducts of power stations and hot air ducts of cement plants. The circular structure bears uniform force, and butt welding or fillet welding is generally used during welding. The common practice of ports is: a section of metal stub (or flange) is welded to the pipe, and the other end of the stub is pressed with a non-metal ring band. Note that the non-metallic loop strip itself cannot be welded directly, so "welding" is actually for a metal connection.

2. Rectangular non-metallic expansion joint-absolute shipment workhorse

If you go to the boiler flue site at a power station, 99% of them use rectangles. Why? Because the rectangular flue has high space utilization rate, it is easy to stick to the wall. The welding method is also special: the metal frame of rectangular non-metallic expansion joint is usually made of angle steel or channel steel, which is welded directly to the flue wall panel. The ring belt is fastened to the frame by platen bolts instead of welding. So "welding" only takes place between the metal frame and the flue.

In order to save costs, some manufacturers make the frame thin, and the deformation after welding is serious, resulting in air leakage due to weak pressure of the ring belt. Therefore, when choosing rectangular non-metallic expansion joints, be sure to ask about the thickness and material of the frame plate, and don't just look at the quotation.

Third, according to the material: fabric fiber, rubber, rubber PTFE, which can be welded firmly?

The material of the non-metallic ring belt determines the temperature resistance, corrosion resistance and sealing performance. Here are three mainstream materials, which you can take according to the working conditions.

• Fabric fiber expansion joint: i.e.Non-metallic expansion joint (fabric fiber expansion joint)。 The main body is made of silicone cloth, glass fiber cloth, ceramic fiber cloth, etc., and the temperature resistance can reach 1200℃ (with heat insulation layer). After the port metal parts are welded, the ring belt is pressed mechanically, which is not directly affected by the welding heat. This is the most used in flue and cement kiln tails of power stations.
• rubber compensator: The material is natural rubber, neoprene or EPDM, and the temperature resistance generally does not exceed 150℃. Note when welding: the rubber ring belt must not be close to the high-temperature welding area. The metal parts must be welded first, and then the rubber ring belt must be installed after cooling. Many on-site accidents are caused by welding slag splashing onto the rubber.
• Rubber PTFE compensator: Lined with PTFE layer and rubber, taking into account both corrosion resistance and elasticity. The temperature resistance is a little higher than that of pure rubber (about 200℃), but it is also afraid of high welding temperature. Generally used in desulfurization systems, the medium contains acidic gas or slurry. The welding requirements are the same as the rubber compensator, and the heat source must be isolated.

What are the welding non-metallic compensators? From the material classification, there are these three mainstreams. But some people will ask: Can you weld PTFE directly? Wake up, the melting point of PTFE is only 327℃, and the welding melts directly. Therefore, as long as it is a "non-metal" loop strip, it must pass through the transition of metal parts before it can be welded.

IV. Practical application scenarios: power station flue, cement hot air, desulfurization system, each choose its own goods

Different scenarios have completely different choice logics. The question "What are the welding non-metallic compensators?" When put on the spot, the answer becomes "You can decide after looking at the working conditions".

Scenario 1: Power station flue (boiler outlet, dust collector inlet)

The medium temperature is generally 300-700℃, containing a small amount of dust. PreferredNon-metallic expansion joint (fabric fiber expansion joint)Rectangular structure, high temperature resistance and can absorb multi-directional displacement. Welding method: The wall thickness of the flue is generally 6-10mm, and the frame should be welded directly. The kerosene penetration inspection should be done in the welding seam. Frequent questions: The insulation layer is not done properly, and the temperature of the external metal frame is too high, which leads to thermal stress cracking of the weld.

Scenario 2: Hot air duct (kiln head, grate cooler) in cement industry

The temperature is higher, reaching above 1000℃, and contains a lot of clinker dust. Fabric fiber expansion joints with thermal insulation must be used, and heat-resistant steel (e.g. 310S) should be selected for metal connections. Preheat during welding and heat preservation after welding to prevent cracks. OurMetal Corrugated Expansion Joints in Cement IndustryAlthough mainstream, it is still more economical to use rectangular non-metallic expansion joints for large-section flues.

Scenario 3: Desulfurization system (FGD import and export)

Low temperature (50-80℃), strong corrosion (SO₂, chloride). Circle belt preferredRubber PTFE compensator, or a rubber compensator lined with PTFE. Metal parts must be coated with anti-corrosion coating or duplex stainless steel. Note when welding: Desulfurization pipelines are often lined with rubber or plastic, and welding heat will destroy the lining, so the welding sequence should be designed well: first welding metal connectors, then fill the lining. This detail is wrong, and the later leak will be repaired until you cry.

Speaking of which, do you still think "welding non-metallic compensators" is an easy multiple choice question? Choose the wrong material, and it will leak after welding; Choose the wrong structure and can't fit it; Choose the wrong scene and scrap it in half a year. Doubling the cost is light, and delaying the construction period is really bad.

Next time you communicate with the manufacturer, just report three parameters directly: temperature, pressure and media composition. Leave the rest to us. Oh, by the way, don't forget to confirm whether the port is welded or flanged-don't be like the brother at the beginning, ask "welding non-metallic compensator" when you open the mouth, but when you buy it back, you find that you don't even have welding parts.

Splash cold water first: The non-metallic compensator itself does not leak water, but this structure leaks water

Give the answer directly —Non-metallic compensator(That is what we often sayNon-metallic expansion joint、Fabric fiber expansion joint) The body will not leak. The reason is very simple. Its main body is a composite layer of fabric and rubber, which is not a dense metal. If it was waterproof by itself, it would have leaked into a fountain.

What really carries the waterproof banner is the internalSealing layerAnd externalskinThe cooperation of. The sealing layer is usually made of fluororubber, silicone rubber or polytetrafluoroethylene film, which is responsible for blocking air and water. The skin (several layers of high-strength fiber cloth plus rubber) provides strength and prevents the sealing layer from bursting by pressure. Once one of the two partners dropped the chain, the water found the seam to drill.

By what waterproofing? Cooperation of sealing layer and skin

TakeNon-metallic expansion joint (fabric fiber expansion joint)In terms of structure, it is generally like this from the inside to the outside: the innermost layer is a corrosion-resistant sealing layer, the middle is a heat insulation layer (such as ceramic fiber felt), and the outer layer is a skin. The sealing layer is like a raincoat, and the skin is like a jacket shell-a hole in the raincoat is useless no matter how waterproof the outside is.

So when you ask "Do non-metallic compensators leak?"The correct answer is: it does not leak itself, but once the sealing layer is aged, damaged or selected incorrectly, what leaks is the peace of mind you bought at a large price.

Dismantling of Water Leakage Case: Rectangular Non-metallic Expansion Joint of Cement Plant Drips in Half a Year

Two days ago, a customer from a cement factory reported that they usedRectangular non-metallic expansion jointInstalled on the kiln tail smoke gas pipeline, it began to drip water in less than half a year. The scene was so anxious that he jumped his feet, thinking it was a product quality problem. As a result, when I removed it, I saw that the sealing layer was full of corrosion holes, but the skin was intact.

What's the problem?

• Flue gas temperature fluctuates year-round: In the design, the silicone rubber sealing layer was selected at 180℃. As a result, the actual operation sometimes rushed to 250℃, and the silicone rubber was directly carbonized and brittle.
• There is condensed acid in the medium: The flue gas contains sulfur, and the temperature drops after shutdown to form sulfurous acid. The ordinary sealing layer can't bear it, and it will perforate in a few months.

This pot really shouldn't be left to the non-metallic compensator-the working conditions were not accurately calculated in the selection stage.

Pits buried in the design and selection stage: temperature, corrosion and pressure, none of them can be missed

No matter how cow the sealing layer is, it is also afraid of "cross-border rape". Three key parameters don't match up, and it is only a matter of time before water leaks:

• Flue gas temperature: Select silicone rubber or perfluorororubber at high temperature, and use EPDM with good aging resistance at low temperature (such as wet chimney after desulfurization). Don't take the general-purpose type to carry the high temperature of 300℃, that is, force the sealing layer to commit suicide.
• Medium corrosivityPolytetrafluoroethylene film or fluororubber sealing layer for acidic gas; Alternative formulation for alkaline or oil mist environments. Customers often ignore the corrosion of condensate and choose an ordinary rubber, which leaks in half a month.
• Pressure rating: Non-metallic compensators are generally used in low-pressure or negative-pressure pipelines, but when the pressure fluctuates greatly, the sealing layer will be "blown and bulged" and then torn. Design with a margin at least 20% higher than the actual pressure.

To put it bluntly, the non-metallic compensator is like a custom suit, and only by measuring the body (working conditions) and tailoring (material selection) can it fit. Buy the ready-made universal model when you come up, and don't shout for the leakage.

The most overlooked details of installation and maintenance

Select the right type, install the hand shake, still leakage. Three details are the hardest hit areas:

Has the tie rod nut been adjusted in place?

Non-metallic expansion joints, usually with tie rods, are used to limit displacement. According to the specification, the tie rod nut should be adjusted to the pre-tensioned or pre-compressed position after installation (see the design drawings for specific data). Many workers screwed to death directly, or didn't adjust it at all. As a result, the skin was torn when the pipe was thermally expanded, and the sealing layer suffered. Refer to our site Q&A"How to adjust the tie rod nut of the expansion joint"It should be divided into two steps: first loosen the nut to the free state, and then adjust the positioning nut according to the compensation amount.

Is the deflector in the right direction?

Non-metallic compensator with guide tube, the arrow must point to the direction of media flow. When installed backwards, the airflow directly washes the edge of the sealing layer, and the wear is aggravated. There was once a client who putRectangular non-metallic expansion jointThe guide tube was installed backwards and worn out in three months. We have written about the specific function of the guide tube, and the core is to protect the sealing layer from being damaged by high-speed particulate matter.

Is the bolt torque enough?

The flange bolts can't be tightened, and the water will seep as soon as the sealing surface runs out. But it can't be screwed dead-the strength of non-metallic skin is limited, and the excessive torque of bolts will crush the skin, resulting in local deformation and cracking. The standard practice is to use a torque wrench and tighten it symmetrically three times according to the torque value given by the manufacturer.

What if a non-metallic compensator leaks? Don't be in a hurry to change, check these 4 places first

When you encounter a water leak, don't scold the manufacturer first, and don't rush to place an order for a new one. Sequencing in order:

1. See if the sealing layer is partially damaged: Open the observation port or remove the skin (be careful not to tear it), and check whether there are holes, cracks and bulges on the sealing layer. If it's just a small hole, you can temporarily plug the leak with special repair tape, and then replace it after shutting down.
2. Check if the tie rod nut is loose or stuck: If the tie rod nut is loose and the displacement is uncontrolled, the sealing layer may be torn. Reposition the nut to make sure it is within the set stroke.
3. Verify that the guide tube is detached or installed backwards: The guide tube falls off, and the high-temperature flue gas directly rushes the sealing layer, which can be burned through in a few minutes. Re-fixed or replaced.
4. Measure actual media temperature and composition: Many water leakages are actually due to the change of working conditions-for example, the original burning coal is now mixed with biomass, and the flue gas composition changes, so the sealing layer can't bear it. In this case, the type must be re-selected and the material of the sealing layer must be changed.

80% of the water leakage problems are not the poor quality of the compensator itself, but the hidden pits in the selection, installation and maintenance. After these three links are controlled, the non-metallic compensator will last for three to five years.

By the way, if you still leak after checking, don't hold on. Contact the manufacturer to provide the working condition parameters and let professional technicians recalculate it. It is much cheaper to replace a sealing layer than the entire compensator, and it does not have to move the pipes-this isNon-metallic expansion jointAdvantages of modular design.