Describir: Unfired pressure vessels :

 _    _     _____     ______   _    _     _____      ___      ______  
| |  | ||  |  ___||  /_____// | || | ||  / ____||   / _ \\   /_   _// 
| |/\| ||  | ||__    `____ `  | || | || / //---`'  / //\ \\    | ||   
|  /\  ||  | ||__    /___//   | \\_/ || \ \\___   |  ___  ||  _| ||   
|_// \_||  |_____||  `__ `     \____//   \_____|| |_||  |_|| /__//    
`-`   `-`  `-----`   /_//       `---`     `----`  `-`   `-`  `--`     
                     `-`                                              
   ___    
  / _ \\  
 / //\ \\ 
|  ___  ||
|_||  |_||
`-`   `-`