Sealing system: Mechanical Seal MS or Sealless SL
Mechanical Seal = MS Usage: Pump tubes with MS are recommended for crystallizing,
hardening and solid containing liquids. | Sealless = SL Usage: In all other cases you should give preference to sealless design because a sealless pump cannot fail by running dry. |
| 
|
...not be allowed to run dry! | ...can briefly run dry! |
http://www.lutz-pumpen.de/en/desktopdefault.aspx/tabid-46/232_read-302/232_page-1/