Cell biology (formerly called cytology, from the Greek ÎºÏÏÎ¿Ï, kytos, vessel) is a branch of biology that studies the different structures and functions of the cell and focuses mainly on the idea of the cell as the basic unit of life.
(B) For a cylinder having a water capacity over 12 pounds-- (1) By hydrostatic test without determination of expansion (modified hydrostatic test method). A retest must be performed 12 years after the original test date and at 7-year intervals; or (2) By hydrostatic test using the water jacket method. A retest must be performed 12 years after the original test date and at 12-year intervals thereafter.
If the fluid handled by piping system is liquid then the pipe must be hydrotested. If the fluid handled is vapour or gas then the internal design pressure dictates the testing method. For pipe design pressure 10 bar and above the pipe is hydrotested. For pipe design pressure below 10 bar pipe is pneumatically tested.