Metal springs advantages

Unfortunately, a lot of the operational objectives for the POSRV described above could not be achieved as economically as with a spring valve the use of soft seats was imperative to obtain all advantages, which limits the use of most POSRVs in high temperatures (typically up to 300°C maximum). There are now POSRVs in the market with metal-to-metal seats, but here tightness, especially after a few operations, decreases much more than with resilient-seated valves and even traditional spring-operated metal-to-metal valves. 

Some highly accurate spring balances are typically made out of fused silica (quartz glass) and used in vacuum systems. The use of fused silica has two advantages. For one, the material is extremely nonreactive. Thus it is unlikely to corrode as a metal might when in contact with acids and/or oxidizers. In addition, glass is considered perfectly elastic until the point of failure. Thus, there are no hysteresis problems. 

The Yamaha portable headphones were designed with the unique properties of HYTREL in mind, in conjunction with the advantages of other thermoplastics such as DELRIN and ZYTEL . The polyester elastomer spring side pieces, replacing metal and built into the headband, cause the assembly to coil when not in use, with the... 

Applications. Aircraft fasteners, especially rivets, and sheet metal parts where cold formabil-ity and strength potential can be used to greatest advantage. Commercial applications have included springs and orthodontic appliances. Possible use in plate and foiging applications where high strength, deep hardenability, and resistance to stress corrosion are required and somewhat lower ductility is acceptable. 

---