Do you want a guide on how bellow globe valve work and how to select the suitable valve for business? In this article, you will learn a complete guide on how the bellow globe valve work and the selection guide.
Industrial valves are simple machines that develop to adjust the fluid flow by pipes. Mainly valves are used in the domestic system, commercial buildings, and various applications.
In contrast to the other types, globe valves offer greater accuracy for handling flow. Bellow Seal Globe Valve comes with a spherical shape and is often used where fluid flow needs to control. The worth of globe valves for others valves is that they can be adjusted to flow and do not leak. Usually, water pipes fit with these types of valves so that the system can control the inner flow side of the pipe by entirely or partly opening the valve.
Defining Bellow seal globe valve?
Most industries need Bellow Seal Globe Valves for their applications. Such industries contain automation control, fluid transfer, etc.
Many features of the bellow values help pass the explosive media. The typical use of the bellow seal valve is to create a block between air and liquids. Also, it assures zero fluid leakage of pipelines. Do you think here how to avoid processing fluids affecting the valve stem?
The bottom of the bellows is welded to the stem. In contrast, the flip side makes a static seal between the valve’s body and the bonnet. To prove good strength, workers focus on creating multi-functional and energy-saving valves.
How Does Bellow Seal Globe Valve Work
A Bellows Globe Valve has a good structure that uses bellows to seal the valve stem parts. This valve has a bellow inside, and the lower bellows join to the stem to keep the system from corrosion. To create a permanent seal, the other end is direct between the body of the valve and the cover of the valve. The joining bellow keeps stable working efficiency and prevents the vibration of the stem. This makes a double seal configuration that eliminates leakage when the bellows collapse.
Working principle for Bellow Seal Globe Valve
Different positions or instructions can make in possible ways during the installation. The following positions will save the media accumulation bellow. During the process, it requires to keep the pipes clean and installed not to have impurities. To make such a connection, you should avoid tension that acts on the valve.
A unique method follows in the below case that is not like the other kinds of valves. A metal tube joined to the valve in bellow valves creates a leak-proof seal with resistance.
To make the bellows compress and stretch, you should use the accordion ribs with a linear stem motion. The port on the extended bonnet serves as the connection point to avoid fluid leakage. In some other applications, the Off and on system users take quick action on detection.
The analyzer sensor used in the system is as modest as can be calibrated at some pressure level. The detector sensor may leak with the packing on the bellow seal breakage. This will ensure quality work until repairing work gets completed.
Why Do You Need a Bellows Sealed Globe Valve?
There are lots of benefits that you should consider when using the design bellows the valve. The double-sealed design valve provides zero leakage of the stem element. Bellow globe valve offer protection, which can meet the standard of sealing.
You need to use a bellows sealed globe valve to maintain the sealing of the components. Because it can work in unfavorable environments
How do we choose the bellow globe valve?
Selection Guide for Bellows
- You may choose the internal diameter according to the diameter of the valve stem. The inner diameter of the bellows must be larger than the stem diameter, which is 115 mm.
- The outer diameter of the bellows chooses according to the inner diameter of the bellows. The outer and inner diameters link by the percentage of the outer diameter to the inner. In the all-around, the proportion of the outer diameter to the inner diameter is 113-115mm.
- The wall thickness, number of layers, and length of the folded pipe must fulfill the pressure resistance.
- Under normal conditions, more thickness of the bellows needs when there are high forces. When the thickness of one layer can reduce, the number of layers of the bellows can increase.
- For handling higher pressures, the considerable design bellows suggests. You can increase the pressure of the bellows by 2 or 3 piles of the metal wall in the design bellows. You can increase pressure from 80% to 100% by using a double seal bellow of the same thickness. The stroke length reduces if a single layer bellow a thickness equals the pressure of two bellow use. So, we benefit from the best design over the thick bellows.
- The designed guide structure must be followed to prevent the distortion of bellows.
- To avoid early failure, local contact between the valve stem or bellows should avoid.
- The design of the bellow should prevent twisting & deformation of the bellows.
- The valve design limits the compression and extension stroke of the bellows. This is to prevent reduction and tensile extension above the cycle life test of the bellows. In normal conditions, the stroke of the bellows should not exceed 25% of the free length. It will affect the cycle life of the bellows, especially the valve, under high pressure or high temperature of the environment.
- The bellows gain the same temperature and pressure grade as the Bellow seal Globe Valve. The bellows must bear the pressure test of the nominal pressure of the main valve at 38 ℃ and 115 times. Ensure the weld does not crack or leak, and the bellows should not twist during the pressure test.
- The bellows components’ material should be selected within the normal temperature range. And also, the material should have good compatibility with the medium.
How to prevent the bellows globe valve from multi-functioning during use?
You should always read all warnings and instructions to prevent injury or damage. Using other changing parts or the wrong steps may affect the system’s efficiency. In case of an eroding chemical, you should use double-seal bellows to get two protective sealing layers.
If you see the smell of media in the air, it is generally due to the bellows being damaged by the medium. You can change the bellows by yourself or get them replaced by an expert. Change it to stop a threat to life, prolonged negligence, and full damage valve.
A tightened gland nut can cause excessive packing wear and hinder the plug stem’s free movement.
Here are some points you should consider checking before operation:
- Precaution for use
- Do not use corrosive fluids.
- Do not let liquid freeze inside the pipe
- Check that the bolts/nuts are not loose
- Avoid impact pressure such as by the water hammer.
- Do not apply a higher pressure than the largest allowable working pressure.
- To keep the tightness of the valve seat the valve needs to close with enough strength given to the handle. But do not turn the handle with a jig since the manual operation is enough. Similarly, do not turn it if you use a supplementary handle.
- The disc has high sealing characteristics and is suitable for gaseous or liquids-containing scales. But, make sure not to forcedly close the disc as it is made of soft resin because it will be damaged.
Easy maintenance
Packing replacement and gland retightening are not required, lower troublesome maintenance works.
No stem leakage
The stem area is sealed with multi-ply bellows, and gland packing prevents stem leakage.
Protection Of The Quality Of Line Fluids
Fluids are protected from contamination caused by foreign objects.
Saving Manufacturing Costs
If there is no loss of the line fluid through the stem area, it will increase your productivity.
Wide Range of Applications
Valve bodies are made of stainless steel design with high corrosion resistance. Valves easily handle toxic fluids, steam and heat transfer media, and vacuum service.
Summary
Above, we have explained the working principle, selection, and protection bellows valves. The Bellow seal valve has reliable sealing, excellent performance, and a beautiful structure. The sealing surface provides corrosion and friction resistance and reduces cost. It will also ensure zero stem leakage and no maintenance to the system. Consider the precautions mentioned above before operating. Do not use corrosive media, and keep the pipes clean. We hope you understand well; if you have any questions, contact us.
