Soldering other precipitation may wash the lead into the groundwater. Unfortunately, most lead-free solders are not eutectic formulations, melting at around , making it more difficult to create reliable joints with them. Other common solders include low-temperature formulations (often containing bismuth), which are often used to join previously-soldered assemblies without unsoldering earlier connections, and high-temperature formulations (usually containing silver) which are used for high-temperature operation or for first assembly of items which must not become unsoldered during subsequent operations. Alloying silver with other metals changes the melting point, adhesion and wetting characteristics, and tensile strength. Of all the brazing alloys, silver
Compression seal fitting or conductors from twisting and shearing. One or more insulators may also be included when electrical isolation is required. Soft sealant technology for compression seal fittings was developed in the 1950s by Conax Technologies. Since then, compression seal fittings have evolved to include multiple variations for different applications. Some applications include: Single-element compression seal fittings are used to seal a single element such as a temperature probe, tubewell, pipe, etc. Multiple-element compression seal fittings are used when multiple elements of the same or different diameters such as metal tubing, ceramic or rigid plastic tube or pipe, temperature probe, a tubewell,