MR95 Series
12
Overpressure Protection
WARNING
!
Personal injury, equipment damage or 
leakage due to escaping accumulated gas 
or bursting of pressure-containing parts 
may result if this regulator is:
• Overpressured
•  Installed where service conditions 
could exceed the limits given in the 
Specications section and on the 
appropriate nameplate
•  Where conditions exceed any ratings of 
adjacent piping or piping connections
To avoid such injury or damage, provide 
pressure-relieving or pressure-limiting 
devices to prevent service conditions from 
exceeding those limits.
The Types MR95H and MR95HD regulators have an 
outlet pressure rating equal to the inlet pressure rating. 
The Types MR95L, MR95LD, MR95HP and MR95HT 
regulators have an outlet pressure rating lower than 
the inlet pressure rating.
The recommended pressure limitations are 
stamped on the regulator nameplate. Some type of 
overpressure protection is needed if the actual inlet 
pressure exceeds the maximum operating outlet 
pressure rating. Provide external overpressure 
protection if the regulator inlet pressure is greater than 
the safe working pressure of downstream equipment.
Common methods of external overpressure protection 
include relief valves, monitoring regulators, shutoff 
devices and series regulation.
Regulator operation below the maximum pressure 
limitations does not preclude the possibility of damage 
from external sources or from debris in the pipeline. If 
the regulator is exposed to an overpressure condition, 
inspect it for any damage that may have occurred.
Startup
Note
The Specications section and Tables 3 
and 4 show the maximum inlet, the 
differential and the outlet pressures for 
specic constructions. Use pressure 
gauges to monitor inlet pressure, outlet 
pressure and any loading pressure 
during startup.
1.  Check that proper installation is completed 
and downstream equipment has been 
properly adjusted.
2.  Make sure all block and vent valves are closed.
3.  Decompress the control spring by turning the 
adjusting screw (for Types MR95L, MR95H, 
MR95HP and MR95HT) or handwheel (for 
Types MR95LD and MR95HD) counterclockwise. 
4.  Slowly open the valves in the following order:
a. Loading supply and control line valve(s), if used
b. Inlet block valve
c. Outlet block valve
5.  Set the regulator to the desired outlet (control) 
pressure according to the Adjustment procedure.
Adjustment
WARNING
!
To avoid personal injury, property 
damage or equipment damage caused 
by bursting of pressure containing parts 
or explosion of accumulated gas, never 
adjust the control spring to produce an 
outlet pressure higher than the upper 
limit of the outlet pressure range for that 
particular spring. If the desired outlet 
pressure is not within the range of the 
control spring, install a spring of the 
proper range.
The factory setting of the regulator can be varied 
within the pressure range stamped on the nameplate. 
Follow the following procedures for the proper 
adjustment of the outlet (control) spring. If the spring 
range was changed, be sure to change the stamped 
spring range on the nameplate.
All MR95 Series regulator springs can be backed off 
to provide zero outlet. Recommended outlet pressure 
ranges available, maximum inlet pressures and color 
codes of the respective springs are shown in Tables 3 
and 4.