characteristics of Welded Metal Bellows
1.welded metal bellow has superior followability.
Since it is fully enclosed, the dynamic and static ring and the dynamic ring seal of the shaft sleeve (or shaft) that are necessary in the common spring seal are eliminated in structure, so that the elastic rate of the bellows itself is fully utilized to form a specific pressure. In the process of use, ordinary mechanical seals often cause the pump body to be evacuated due to various reasons such as device fluctuations or operating processes. At this time, the existence of the moving ring seal makes the end face unable to be reset in time after opening, resulting in mechanical seal leakage and ripples. Tube mechanical seals structurally eliminate this path to seal failure. Because it is hardly affected by the pump body evacuation, it shows good compensation, and it has outstanding performance in pumps such as light hydrocarbon pumps and vacuum tower bottom pumps that are easy to evacuate, so that the bellows seal can be widely used.
2.The welded metal bellow is resistant to high temperatures.
Since the bellows seal is not affected by the moving ring seal in the ordinary spring seal, the applicable medium and temperature are greatly expanded. Usually, the material of the moving ring seal of ordinary mechanical seals is mostly organic compounds such as PTFE rubber. These organic compounds will have chemical reactions with the medium in some media, and will change their physical properties at low and high temperatures,resulting in hardening and failure of the seal.
3.welded metal bellow has balance.
Compared with ordinary seals, bellows seals do not need to process steps on the shaft sleeve, and can establish a balanced diameter and are in a balanced state (usually partially balanced). Moreover, the inner and outer diameters of the bellows can be adjusted to achieve the ideal state, so the bellows seal is generally designed as a balanced type in application.
4. Welded metal bellow has less leakage points.
The sealing point between the moving ring and the static ring is sealed and connected by metal or non-metallic gaskets by bolting, so it is difficult to leak. In fact, the leakage point of the bellows seal is only the dynamic sealing point of the friction pair, which undoubtedly has a large leakage probability. reduce
https://www.grandseal.net/product/welded-metal-bellows-used-in-vacuum-valve-and-semiconductor