- For 20" manhole, with 3" TTMA flange
- Any necessary maintenance is easy to perform
- Rugged cast aluminum
- Can be installed to open in sequence with another pneumatically controlled device such as the emergency valve, or open independently by simply plugging the lower of the 2 ports. (use a 1/4" male NPT plug).
- Flange adapter, 40193AL, is available to adapt 3" TTMA to a parker style vent