Archive for January, 2008

Jan 12

Mechanical Seals with 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 demandingapplications.
      – Solid single piece construction.

METBEL  metal bellows mechanical seals  have dedicated our resources to promote and   develope 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.


Metal Bellows on Wikipedia

posted by petermetbel
Jan 2

Bellows technology of the twentieth and twenty-first century is centered on metal bellows. These high-technology products bear little resemblance to the original leather bellows used traditionally in fireplaces and forges.

There are two types of metal bellows – formed and welded. Formed bellows are produced by a variety of processes, including mechanical forming and hydroforming. The welded bellows is manufactured by welding individual formed diaphragms. The pro and con comparison between the two (formed and welded) bellows generally centers around cost and performance. Formed bellows generally have a high tooling cost, but may have a lower piece price. However, the formed metal bellows has significantly lower performance characteristics. Welded metal bellows are produced with a lower tooling cost and maintain significantly higher performance characteristics. Another area of comparison is in metals of construction. The formed bellows is limited to metals with high elongation characteristics, whereas metal bellows may be fabricated from a wide variety of standard and exotic alloys, such as stainless steel and titanium, as well as other high-strength, corrosion-resistant materials.

Welded bellows can be fabricated from a greater variety of exotic metals and alloys, whereas formed bellows are limited to alloys with good elongation – brass being a prime example. Welded bellows are not fabricated from brass because of its fundamentally poor weldability. Other advantages to welded bellows include compactness (higher performance in a smaller package), ability to be compressed to solid height with no damage, resistance to nicks and dents, and dramatically greater flexibility.

The welding of metal bellows is a microscopic welding process, typically performed under laboratory conditions at high magnification.

Welded metal bellows are used in a wide variety of products and marketplaces, including medical applications like implantable drug pumps, to industrial seals, sensors and actuators, to aerospace applications such as altitude sensors and fluid management devices (accumulators, surge arresters, volume compensators, and fluid storage). Welded metal bellows are also found in space applications, providing reservoirs with potable water as well as accumulators to collect waste water.