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