Metal Bellows Mechanical Seals Design Features
1.  Wide service range from cryogenics to heat transfer liquids and corrosive chemicals.
2.  Long MTBR(Mean Time Between Replacement) since there is one moving part, metal bellows.
3.  Flexible bellows construction eliminates seal hang-up due to solids or dirt in pumpage.
4.  Metal sealing wedge eliminates temperature restrictions of elastomers or plastics.
5.  Built-in hydraulic balance eliminates step in shaft or sleeve.
6.  Available for either inside or outside mounted.
7.  Stabilizer tabs prevent possible damage due to vibration and excessive shaft run-out.
Metal bellows mechanical seals will not fret the shaft or sleeve because it has no dynamic (sliding) 0- ring. All pusher seals (seals with springs) have dynamic 0-rings. This means that you can mount either metals bellows mechanical seals directly on the shaft and save the cost of sleeve. Because the bellows that act as spring does not have to overcome 0-ring friction drag, as does the  pusher seal, the spring load can be lighter than in the pusher seal design. Some common pusher seals have spring loads about 50 psi, while the metal bellows load is approximately 25 psi. This can result in up to 50% decreased seal face wear rate. The metal bellows produces even face loading, superior face tracking and less frictional heat.

Metal bellows mechanical seals feature a metal bellows core made of one of several types super alloy or steel.   The most common are AM350, Inconel 718 and  Hastelloy C-276.   Usually with Alloy 42(Carpenter 42), Stainless Steel (SS 316) end fittings permits these metal bellows mechanical seals to be used for services beyond the range of mechanical seals with elastomer as secondary sealing element.
Typical applications include: cryogenics, heat transfer fluids, severe chemicals, slurry and corrosives at temperatures from —350° to +800°F (—212° to +425°C) with standard seal construction.

Mechanical Seals with Edge Welded Metal Bellows design has several obvious advantages compared to pusher or elastomer bellows design. Some of  them are as follows:
- Dynamic o-ring is eliminated. Superior performance, no hang up or shaft fretting.
- Hydraulically balanced seal. Allows seal to handle more pressure without heat building up.
- Self cleaning. Centrifugal force throws solids away from seal.
- Fits small seal envelope.
- Available in metric and imperial sizes.
- Bellows spring design allows 360 degrees even face closing force.
- Various choices of seal face, elastomer and metal materials to suit demanding applications.
- Solid single piece construction.

METBEL believe in Edge Welded   Metal Bellows mechanical seals’ future and have dedicated our resources to promote and   develop design to cope with customer’s demanding application. Please go to our Product page to explore our metal bellows that  suitable to your application. In case you  have any   questions, suggestions, comments or can not find what you are looking for, please feel free to contact us. We will reply in next business day.