| Even if you are a professional researching information | | | | specifications of the job in hand. Often, a |
| on metal bellows for technical solutions and for | | | | custom-made alloy can be designed to meet a job's |
| installation of industrial processes, it can sometimes be | | | | requirements. |
| helpful (even to the professional) to gain an overview | | | | What specific applications are there for this |
| of the product, what it can do, and just what situations | | | | technology? |
| it has been developed for. | | | | The central purpose for metal bellows is in fluid |
| This guide will give you a few general pointers, and | | | | management. This, however, finds use in a great many |
| hopefully answer some of the questions you have. Of | | | | things. Expansion joint solutions have been employed in |
| course, it is a guide only; for detailed answers to any | | | | industries and technologies such as altitude sensors, |
| specific questions you have about projects you may | | | | piping for industrial coolant, the petrochemical industry, |
| have in mind, we recommend contacting an expert in | | | | applications involving steam, the nuclear power industry, |
| the field. | | | | medical technology, waste management, and some |
| What does a metal bellows actually do? | | | | automotive engines and pump systems. |
| A metal bellows is the term for an attachment on | | | | What kind of tolerances can be built into it? |
| piping typically designed to absorb and mitigate the | | | | A metal bellows can be designed to cope with a wide |
| effects of directional change and to minimize any | | | | variety of different stresses and pressures. The three |
| issues arising from this such as clogging, pressure | | | | main types of movement are referred to as lateral, |
| points on the bend, or expansion of the joint. | | | | axial and angular. |
| It is a development of the basic expansion joint idea | | | | Lateral is a movement of the two ends of the joint |
| used on installations like rail tracks to deal with the | | | | where those ends stay parallel to each other. Axial is |
| expansion and contraction of metal. The central | | | | either the stretching or flattening of the expansion joint |
| concept to keep in mind is that when subjected to | | | | along its length. Angular movement is simply the |
| force, either heat or pressure, the metal bellows allows | | | | curving round of the joint along its axis. At present, |
| the expansion joint to bend rather than break. | | | | expansion joints can be designed to cope with any of |
| Why metal? | | | | these three specific stress types. |
| Metal expansion joints are, simply put, stronger than the | | | | The one type of movement they cannot deal with, |
| alternatives (plastic, ceramics, etc). They are also | | | | however, is torsion, namely twisting along the piece's |
| easier to shape (although metal bellows are relatively | | | | length. This is best avoided by keeping the joint |
| intensive to create). | | | | fastened in place by external attachments, and taking |
| They are also more capable of coping with extremes | | | | care with the fastening when attaching it in the first |
| of temperature, as they themselves can expand and | | | | place. |
| contract without sustaining the weathering damage | | | | How much heat can a metal bellows withstand? |
| that hard plastic would. There are rubber versions | | | | This varies greatly depending upon a variety of |
| available, but their use is strictly limited, and in any | | | | factors; the alloy chosen, whether or not any |
| situations involving heat, for example, they are | | | | anti-corrosives are added, the design of the bellows |
| impractical. | | | | itself, and whether it was welded or shaped. There are |
| Heat-tolerant bellows and expansion joints can be | | | | certain practical solutions and physical limits, but as long |
| made from a variety of metal alloys, such as steel, | | | | as the heat is foreseen, joint solutions can usually be |
| titanium, and many others according to the | | | | found. |