Bell & Gossett HS 100D Steam Vents for Radiators 1B Air Valve - Manual (Page 3)

Adjustable ports for
proportional venting.
Port Adjustment
Note: The air valve is factory set on port 6
for fast venting. To change the venting
speed follow “Port Adjustment” instructions.
Venting Speed Port No. For
Fast 5 or 6 Radiation
located farthest
from the boiler
or areas that
are hard to
heat.
Medium 3 or 4 Normal venting
of radiation
under normal
conditions.
Slow 1 or 2 Radiation
located nearest
the boiler or
areas that
overheat.
• Port 1 provides the slowest venting.
• Port 6 provides the fastest venting.
To decrease
venting speed:
1. Loosen nut “A” on the
top of the air valve.
2. Turn cap “B” to the left.
3. Hold cap “B” at the
desired setting and
tighten nut.
To increase
venting speed:
1. Loosen nut “A” on the
top of the air valve.
2. Turn cap “B” to the right.
3. Hold cap “B” at the
desired setting and
tighten nut “A”.
SLOW FAST
No1
2 1 6 5 4
A
B