Nexen BD 933507 - Manual (Page 13)

13 FORM NO. L-20063-AD-0314
This mode allows the selection of any value of spring engaged
torque (from zero to full rated) available with a particular
disc size by relieving a percentage of minimum hold-off
air pressure (5.17 bar [75 psi]). The remaining pressure,
balanced against the spring force, reduces the output of
the Actuator (See Figure 13).
Example: A standard spring set brake with a 610 mm
[24 inch] disc has a full rated spring-engaged torque of
2825 Nm [25,000 in-lb] when using the minimum hold-off
air pressure of 5.17 bar [75 psi]. To achieve 60% of this
torque (1694 Nm [15,000 in-lb]), relieve the hold-off air
pressure 60% or 3.10 bar [45 psi], leaving 2.17 bar [30
psi] hold-off air pressure.
SPRING-ENGAGED / DUAL AIR MODE
3-Way Manual Valve
Air Supply
Filter
Regulator
Lubricator
Power
Source
Power
Source
Regulator
Quick Exhaust Valve used as
a Shuttle Valve
Set at a reduced pressure for less than
full rated torque Quick Exhaust Valve connected to
"Spring Engaged Port"
Figure 12
3-Way Manual Valve
Air Supply
Filter
Regulator
Lubricator
Power
Source
Power
Source
Regulator
Quick Exhaust Valve used as
a Shuttle Valve
Set at a reduced pressure
for less than full rated torque
Quick Exhaust Valve connected
to "Spring Engaged Port"
Figure 13
Air-Engaged Port
Service
Service
Plug
Spring-Engaged Port
o
BSolete
t
hree
-P
ort
a
ctuator
Spring Brake
Service
t
wo
-P
ort
a
ctuator
Spring Brake
Air-Engaged Port Spring-Engaged Port
CAUTION
Do not plug both Service Ports.
Install a breather (such as a
muffler) to one of these two ports.
CAUTION
Do not plug Service Port. Install
a breather (such as a muffler) to
the port.