Yes indeed.
To fill the system:
- close purge valve
- open air trap
- fill the system via the airtrap
To empty the system:
- open air trap
- put a basin under the purge valve
- open it
- wait a few seconds
- done.
All you need is a T and a ball valve at the lowest point:
Code:
-------
--+ +-- <- T
| |
|X+- <- valve
| |
Eheim valves exist in 10mm (3/8"), 12mm (1/2") and i think in 14mm (5/8") and 16mm (3/4")
PS: i forgot once to close the purge vavle before filling... I was thinking "huhh it needs a lot of water" just before noticeing i had flooded my kitchen..