METAL BELLOW MECHANICAL SEALS

Metal bellow mechanical seals are ideal for high temperature applications and harsh chemical services where elastomers cannot be used effectively. This seal type incorporates edge welded metal bellows as a spring-loading mechanism to maintain face contact when the seal is not pressurized and eliminates traditional secondary sealing requirements.

 

Types of Metal Bellow Mechanical Seal

In applications where the process temperature exceeds elastomer capabilities, metal bellows mechanical seals with graphite secondary seals are a good sealing option. metal bellows mechanical seal is designed for high-temperature services typically found in chemical and petrochemical processes. Graphite secondary seals replace O-Rings to achieve the higher temperature requirements. Advanced bellows design distributes pressure uniformly across the span of the bellows plate to reduce stress and minimize weld fatigue. Component design replaces most OEM seals.

 

Metal Bellow Mechanical Seals M14M15M16

Replacement for:

John crane 670

John crane 676

John crane 680

Features:

High temperature

Weld bellow

 

Metal Bellow Mechanical Seals M17

Replacement for:

John crane 515E

Features:

High temperature

Weld bellow

 

Metal Bellow Mechanical Seals M21

Replacement for:

Burgman MFL85N

Features:

High temperature

Weld bellow

 

Metal Bellow Mechanical Seals M22

Replacement for:

Burgmann FMLWT80

Features:

High temperature

Weld bellow

Grafoil seals

Materials Combination for Bellows Mechanical Seal

Face: Carbon, SiC, TC

Seat: Ceramic, SiC, TC

O-rings: NBR, EPDM, VITON, Aflas, FEP, Kalrez, Chemraz, Grofoil, etc.

Spring: SS316, hastelloy C, AM350

Metal parts: SS316, hastelloy C

Recommended Applications of Metal Bellow Seals

Process industry

Oil and gas industry

Refining technology

Petrochemical industry

Chemical industry

Hot media

Cold media

Highly viscous media

Pumps

Special rotating equipment

 

Features of Metal Bellow Mechanical Seals

For unstepped shafts

 

Single seal, balanced, independent of direction of rotation

 

Metal bellows rotating

 

Asymmetric bellows form results in even stress distribution with benefits of greater strength and higher rate of flexibilty; seal is bi-rotational and inherently pressure balanced.

 

Smooth profile is resistant to clogging and therefore ideal for slurries and fibrous liquids. Similarly, seal unit is easy to clean and sterilize in place.

 

Unit construction ensures a simple-to-fit seal, with superior heat dissipation paths. Seal unit is reliable and does not wear the shaft.

 

Graphite secondary seals for high-temperature performance

 

Advanced bellows design for maximum cycle life

 

Rotary bellows for enhanced performance in slurry and particulate services

 

Hydraulically-balanced seal design

 

Blister-resistant carbon

 

Proven heat-treated AM 350 bellows construction

 

Graphite secondary seals for high-temperature performance

 

Why Choose Sealcon as your Metal Bellow Seal Manufacturer?

For extreme temperature ranges

 

No dynamically loaded O-Ring

 

Self-cleaning effect

 

Short installation length possible

 

Pumping screw for highly viscous media available (dependent on direction of rotation).

 

For unstepped shafts

 

Single seal, balanced

 

Independent of direction of rotation

 

Metal bellows rotating, rotating bellows, roller bellows

 

Common malfunction of metal bellow mechanical seals

At high temperature, the bellows are easier to be broken, also the bellows are broken under high pressure (such as the hot water pump).

 

It is easy to occur coking and carbon deposition at the trough between the wave plates, which makes the bellows lose elasticity and cannot compensate, so it can not be used for coking, carbon deposition and crystallized precipitation pump.

 

For external installation high temperature mechanical seal, the sealing surface can be pushed open when the pressure in the sealing cavity is more than 0.2MPa. This is because the elastic force of the bellows is small and can not withstand the high pressure of the medium. Therefore, it is not possible to use an external bellows mechanical seal when the pressure is high.

 

Because the metal bellow type mechanical seal from reliable

China mechanical seal manufacturers is a balanced structure, the effective diameter and load factor must be calculated in use. Otherwise, in the high-pressure propane and propane pump, the phenomenon of "spray leakage" is easy to occur.

 

Difference between Metal Bellow Seal and Ordinary Mechanical Seal

The welded china metal bellows mechanical seal has good floating and random compensation, which can compensate for the leakage caused by wear, axial movement and vibration. Welded metal bellows itself as the elastic element and the sealing function, so there is no need to design the general dynamic auxiliary push ring spring type mechanical seal ring, thus avoiding the fine particles due to dynamic auxiliary seal ring caused by the obstruction, dynamic auxiliary seal and high temperature because of its axial friction resistance reduction the seal compensation ability of the problem.

 

Metal bellows mechanical seal with no auxiliary seal ring, reduce a leak; at the same time reduce the friction resistance compensation mechanism, improve the following; in the petrochemical industry, welding sealing temperature is not restricted by auxiliary seal bellows; for PTFE bellows seal can be used in the corrosive medium. Its drawback is that some bellows have the smaller elastic force and need to add auxiliary springs. However, for critical applications like mechanical seals for Flygt pumps, the enhanced durability and compensation capabilities of metal bellows seals make them a preferred choice for maintaining pump integrity under harsh conditions.

 

Welded metal bellows are made by interlacing and closely welding each internal and external diameters of each wave plate, so no matter whether they are used as the stationary or rotary type, it is not necessary to consider the problem of rotation. Welded metal bellows can be made from precipitation hardening stainless steel, high-temperature nickel based materials and chrome-nickel corrosion resistant materials. Therefore, welded metal bellows can be applied to a wide range of temperature (-117 C - 426 C), and various acid, alkali and salt media. The selection of different thickness and layers of the wave plate makes it withstand a pressure of up to 7MPa in a special pump. The design of welded metal bellows seal is generally balanced, so its pressure bears little influence on the surface pressure. The welded metal bellows mechanical seal is not only suitable for nonhydrocarbon media, but also for flash hydrocarbon medium. Compared with the ordinary mechanical seal, its service life has been greatly improved, so it has a higher ratio of performance and price.

 

China Sealcon adopts the latest technology to produce sealing products, seal spare parts and pump and pump spare parts with long service life.

We supply a wide range of products made of different materials, including rubber, stainless steel, PTFE, carbon, ceramic, Sic, TC, etc. Also, our sealing spare parts are easy to interchange and maintain.