заключён в

The gas is confined in a container.

The compound is embedded in glass.

The capillary tube is encased (or enclosed) in an outer protecting tube.

The operating mechanism is totally enclosed in a case.

The apparatus is housed in a steel case.

The pipe is housed in a cylindrical castiron container.

Источник: Русско-английский научно-технический словарь на Gufo.me