Download Emerson MR105 Instruction Manual

Type MR105
VALVE SPRING
VALVE PLUG
CAGE
seat ring
TYPE Y602-12 VENT
1/2 NPT CONTROL
LINE CONNECTION
actuator stem
DIAPHRAGM
TYPE Y602-12 VENT POINTED DOWN
OR 1/2 NPT PRESSURE-LOADED
SPRING CASE VENT
ACTUATOR
CONTROL SPRING
M1178
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
Figure 2. Type MR105 with Low-Pressure Actuator Operational Schematic
downstream as the regulator opens in response to the
decreased pressure underneath the diaphragm. The
downward motion of the plug allows flow through the
cage into the downstream system.
Increased downstream pressure permits the regulator
to close. The combination of valve spring force and
valve plug unbalance provides positive valve plug
shutoff against the port and upper seals.
Installation
!
Warning
Personal injury or system damage
may result if this regulator is installed,
without appropriate overpressure
protection, where service conditions
could exceed the limits given in the
Specifications section and/or regulator
nameplate. Refer to Overpressure
4
Protection section for recommendations
on how to prevent service conditions
from exceeding those limits.
Additionally, physical damage to the
regulator may result in personal injury
or property damage due to escaping of
accumulated gas. To avoid such injury
and damage, install the regulator in a
safe location.
All vents should be kept open to permit
free flow of gas to the atmosphere. Protect
openings against entrance of rain, snow,
insects or any other foreign material that
may plug the vent or vent line. On outdoor
installations, point the spring case vent
downward to allow condensate to drain.
Under enclosed conditions or indoors,
escaping gas may accumulate and be
an explosion hazard. In these cases,
the vent should be piped away from the
regulator to the outdoors.