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bellows globe valve vs ordinary globe valve

The difference and comparison between bellows globe valve and ordinary globe valve
The bellows globe valve is also called the bellows seal globe valve. Through automatic seam welding, a metal barrier is formed between the fluid medium and the atmosphere to ensure the design of zero leakage of the valve stem. Compared with traditional globe valves, it has the following advantages:

Globe valve (9)

Globe valve (9)

1. The bellows globe valve has a long service life, reduces the number of maintenance and lowers operating costs. The sturdy and durable bellows seal design ensures zero leakage of the valve stem and provides maintenance-free conditions.
2. The valve opening and closing torque is small, reducing labor intensity, and can drive any form of driving device, which is convenient for remote control.
3. The appearance is beautiful, the valve channel has a smooth streamline, and the flow resistance coefficient of the valve is reduced. It is a high-quality energy-saving product.
4. The outer seal of the valve adopts bellows seal and graphite, stainless steel gasket seal, the seal is reliable, and the sealing packing does not need to be replaced for long-term use. In industrial use, the leakage caused by the stop valve: high temperature, highly toxic, flammable and explosive, radiant medium, etc., not only pollute the environment, but also often cause significant personal and property losses. However, this type of valve is much safer and more stable, and strictly adopts foreign advanced standards in design and manufacturing.

Advantages and application of bellows globe valve The bellows globe valve has no leakage, and it is safer to be used in high-risk media. Ordinary globe valve is sealed with packing, the valve stem and packing will slide, and it is easy to leak at low temperature (spool).
The bellows cut-off valve uses a closed bellows that can be stretched and compressed to replace the packing seal, which can effectively prevent external leakage caused by packing loss. It is generally used for the transmission of highly permeable media, such as valves on hydrogen systems, as long as the bellows is not damaged, there is generally no leakage; while the general shut-off valve is sealed with packing, which is prone to leakage.
The opening or closing stroke of the valve stem of this kind of valve is relatively short, and it has a very reliable cut-off function. Also, because the change of the valve seat port is proportional to the stroke of the valve disc, it is very suitable for flow adjustment. Therefore, this type of valve is very suitable for use as a shut-off or adjustment and throttling.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news /knowledge: The structure and characteristics of bellows gate valve; Comparison of bellows globe valve and ordinary globe valve; 

Electric globe valves’ structural features and installation attention

Structural features of electric globe valve:

1. Open and close without friction. This function completely solves the problem of traditional valves affecting the

Globe valve (6)

Globe valve (6)

sealing due to mutual friction between the sealing surfaces.

2. Top-mounted structure. The valves installed on the pipeline can be directly inspected and repaired online, which can effectively reduce device shutdown and reduce costs.

3. Single valve seat design. Eliminates the problem that the medium in the valve cavity affects the safety of use due to abnormal pressure increase.

4. Low torque design. The valve stem with special structure design can be opened and closed easily with only a small handle.

5. Wedge-shaped sealing structure. The valve relies on the mechanical force provided by the valve stem to press the ball wedge onto the valve seat to seal, so that the sealing performance of the valve is not affected by changes in pipeline pressure, and the sealing performance is reliably guaranteed under various working conditions.

6. Self-cleaning structure of the sealing surface. When the ball is tilted away from the valve seat, the fluid in the pipeline passes through the sealing surface of the ball evenly at 360°, which not only eliminates the local erosion of the valve seat by the high-speed fluid, but also washes away the accumulation on the sealing surface to achieve the purpose of self-cleaning .

7. The valve body and bonnet with valve diameter below DN50 are die forgings, and the valve body and bonnet above DN65 are steel castings.

8. The connection forms of the valve body and the bonnet are different, clamp pin shaft connection, flange gasket connection and self-sealing thread connection.

9. The sealing surfaces of the valve seat and the valve disc are all made of plasma spray welding or surfacing welding of cobalt-chromium-tungsten cemented carbide. The sealing surface has high hardness, wear resistance, scratch resistance and long service life.

10. The valve stem material is nitrided steel. After nitriding, the surface of the stem has high hardness, wear resistance, scratch resistance, corrosion resistance and long service life.

Electric shut-off valve installation attention:

1. Pay attention to the flow direction of the medium when installing the valve, and install it strictly in the direction indicated by the valve flow direction arrow.

2. The valve can be installed at any position of the pipeline, and at the same time, choose a carbon steel or alloy steel valve according to the temperature of the medium and the medium.

3. The electric globe valve should be installed vertically as far as possible, with the valve stem upward.

TH Valve is a professional manufacturer of butterfly valvegate valvecheck valveglobe valveknife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Related news /knowledge:
Installation attentions for valves;
Structural characteristics of butterfly valve
Structural characteristics of metal hard seal butterfly valve;
The structural characteristics and uses of the wafer butterfly valve;