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    Are you curious why the heat transfer oil pipelines can use the bellow stop valve? If yes, you are in a great place. In this article, you will learn why the bellow valve is most used in hot pipelines.

    Bellows-sealed valve is often used for stem sealing applications in the nuclear industry. It is also used in pressure-regulating valves, fluid passage, and slight pressure drop loss. It makes stem preventing form radioactive material or maintaining a high volume.

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    Why use the bellows seal shut-off valve for heat-conducting oil?

    In heat transfer, oil pipeline transfer often causes corrosion and other problems. The corrosion will affect the bellows differently, shorten life, and even damage. To prevent this damage, you can use the bellow seal valves. We have described why the bellow seal valve is used in heat transfer pipelines. If you have a question, contact us happily.

    For indirect heat transfer, heat transfer oil has good thermal stability. It can meet the needs of different heating and cooling and broader temperature ranges. Heat-conducting oil heating systems are used in material and chemical fibre industries. High working temperature maintained under atmospheric pressure.

    So bellow valve is used for the safety conditions of the raised-temperature heating system are lower, and the system’s reliability improves. Also, improve the thermal efficiency of the system and reduce initial investment.

    Heat transfer oil affects the heat transfer system and blocks the pipeline. The standard technical design valve should use in the heat oil system. The bellow valve needs oil transfer in the heat and electrical control system. The hot oil system should provide a valve, and they selected the bellows sealed safety valve.

    The valve material of the hot oil system must not be non-ferrous metal or cast iron. The technical design specifications consider its characteristics, low pressure, and high temperature.

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    Bellows Sealed Valves for Your Hot Oil Process Heating System

    The shut-off valve of the heat oil pipeline should use a bellows-sealed globe valve. The packing of the seal valve process is shaped by graphite, making it best for oil resistance. When the thermal oil falls into the graphite, impurities in the graphite dissolve by heat oil; as a result, graphite pulverization occurs, which is the main reason for the packing valve to be told.

    The bellows stop the direct link between graphite and hot oil. The permeability of healing oil is high, about 50 times more than steam. If seal packing chose, easy to leak out, resulting in wasted thermal oil, and the bellow seal has no leakage.

    Heat transfer oil is the residual air in the heat oxidation reaction, and gums stick to the oil pipeline. These impurities cause corrosion and leakage in the pipeline. So the internal parts of the valve are all stainless steel and can resist 425 ℃ high temperatures. It prevents corrosion and has an easy Switching feature.

    Bellows-sealed valves have a structure with a focus ring that avoids corrosion. The guide ring also avoids long-term direct pollution. Because the guide ring only lifts up and down without lateral displacement. It also prevents the impact of high flow velocity on the valve stem.  

    Seal heating fluid systems must need leak-tight security at every joint in the system. Leak risk in the system can risk your employees and cause environmental problems. But, you should have top priority to preventing leaks at your facility.

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    How Do Bellow Sealed Valves Work?

    Bellows sealed valves use as safety measures. When transferring thermal heating fluids puts your employees and environment at risk.

    Developing bellows covers a central stem, replacing the packing box in different systems. These series of metal act as the primary stem-sealing layer with 100% leak tightness. These series contract as the valve opens and expand as the valve closes.

    High-temperature fluids with low viscosity put the joint’s standard valves at risk. They also grow to develop leaks and dangerous chemicals while the valve opens. Thus, thermal fluid heating systems are moving bellows sealed valves with lower risks.

    High-Vacuum Systems

    Closed systems need protection from air leakage for both inflowing and outflowing air. The system should work at a consistent pressure and with external air. A system that depends on bellows sealed valve for flowing fluid needs to keep it airtight. Bellows sealed valves show the most efficient way of sealing against air particles.

    Systems with Hazardous Fluids

    Bellows sealed valves help your system consist of hazardous liquids. Heated oil leaks can have effects on the environment. But bellows sealed valves have a solution against toxic chemicals.

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    Systems with Costly Fluids

    Bellows sealed valves also stop the loss of costly or valuable liquids from your system. Long-term leaks cause costly fluid replacement and affect system efficiency.

    The Benefits of A Bellows Sealed Valve

    Bellows sealed valves built to prevent leaks. The bellows surround the central stem because they weld at the stem component. Bellows also have contact plates, providing resistance to solid metal and air.

    A Bellow seal valve is used in the piping stem to keep it secure against leakage. When they install correctly, they will lower the damage of leakage.

    Three Reasons why Airtight Seals Are Essential For Your System’s Safety

    The Seal Valves Are More Cost-Effective

    Bellows sealed valves are long-lasting, reliable, robust, and have lower maintenance costs. You also spend little help cleaning up or replacing fluids after chemical leaks. Due to the cleaning up, the toxic leaked materials were cut.

    Bellows Can Withstand Pressure

    Every bellow valve can resist vertical expansions and contractions near the valve stem. The welding present strength so high-pressure fluids can not hit through link points.

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    What Factors Need To Consider While Selecting A Valve In A Heat Transfer Oil Pipeline?

    Bellows-sealed valves are often used when the medium is expensive, volatile, and toxic. These materials allow for leakage from a reciprocating stem. This design saves the valve and stems packing from connection with the process fluid. In comparison, the use of box construction bellows prevents catastrophic results.

    So, the usual attention should observe if the packing leakage or the bellows valve may be a problem. You should follow some factors before selecting the bellows seal valve.

    Material: You can choose the lifespan of the bellow seal valve from the composting materials. The material should be compatible and anti-corrosive as stainless steel. 

    Pressure rating: The valve should match the pressure and must adjust the temperatures by the fluid system.

    Easy to Maintain: Bellows valves create of reliable and robust design and provide a maintenance-free condition. The system works excellent, thus minimizing the maintenance cost. Bellow seal valves offer a feature that can support. 

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    What consequences will be if improper selection, use, and maintenance occur?

    Forms of failure of bellows

    The types of failure in the heat transfer oil heating system include insulation fire, area fire, tank fire, and explosion. Many common failures cause leaks or explosions etc.

    The failure form of the bellows also needs extra attention. let’s discuss several categories of bellows valve failure. The first kind of failure is a torsional failure. The main form of bellows failure in regular use is the bellows breakage caused by the twisting. 

    And the valve stem action can not stop the rotation because the actuator and the bellows can not turn back. When the angle of rotation exceeds from limit, it will cause the bellows adhesion to twist dead.

    There are many ways to adjust to torsional failure. The one which increases layers of bellows to improve the bellows’ torsional resistance. This method is suitable but costly. The other cost-effective way is to move the anti-rotation parts to the top of the stem and the lower part of the stem. To prevent the bellows rotation, this program only needs to change the design content.

    Due to the oxidation of the thermal oil, the leakage will cause combustion and explosion. So, the thermal oil valve should be free of external leakage but not free of internal leakage.

    What does the bellow valve play in the heat transfer pipeline?

    Thermal oil systems work at low pressure, which will cause heat transfer efficiency.

    Bellow sealed globe valves have specific designs, making the valve perform better. The design on the bellows needs to carry the form and working conditions for other fluids.

    The bellows process also needs to consider the appearance, economy, cost, and life.

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    The Application Should Pay Attention to The Problem

    With increasing temperature, the pressure level of the bellows seals decreases. The structure of the bellows seal should be considered for use, and you will get it after installation.


    The viscosity of heat-conducting oil is so high in the cold, and the flow resistance is higher. So, the life of the bellows seal valve is better than other valves. The spool is a type of valve that opens fast and can increase the flow speed. To lower the working costs, should use the fast-opening spool bellows-sealed.

    10years experience for bellow seal globe valve,welcome inquiry
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