Model 40PSR Pressure Sensing Relay (High or Low)

DESCRIPTION

The NUTECH Model 40PSR is a three-way 
adjustable block and bleed pneumatic relay. It is 
normally used as a high or low-pressure sensing 
relay that blocks and bleeds the control signal upon 
abnormal pressure conditions. The PSR relay utilizes 
the time-tested method of balancing pressure on a 
piston with an opposing spring force. The relay can 
be bench set or field set at a desired pressure setting 
by adjusting the cap by hand.
The sensed pressure acts on the piston, which 
moves the spool accordingly. When the sensed 
pressure exceeds the setting, the relay blocks the 
supply pressure and bleeds the downstream control 
pressure to the vent port.

FEATURES
Senses pressure ranges from 0.5 psig to 10,000 psig.
Combinations of springs and base pistons deliver 
optimum performance over a variety of pressure 
ranges. 
Springs can be removed or replaced, without 
disconnecting sense line or control 

The relay can be panel-mounted or locally mounted.
Routine maintenance procedures can be performed 
without removing the device from its mounting in 
most applications.
A stainless steel adapter shim is available to retrofit 
the sensor into existing panel holes larger than 1.50”.

SPECIFICATIONS

Model 40PSR
Pressure Sensing Relay (High or Low)
Senses pressure range 0.5 - 10,000 psig 
Control Pressure 125 psig max
Repeatability 1% of range
Deadband
 3” base 3% of range
 7/16” and 1-1/8” base 5% of range
 3/16” base 10% of range
Material 316 SS per ASTM A-276
O-ring Viton®
, Temp. range -15˚F to + 400˚F (std.)
 BUNA-N, Temp. range -65˚F to + 215˚F (opt.)
Diaphragm BUNA-N, Temp. range -65˚F to + 215˚F (std.)
 Viton®
, Temp. range -15˚F to + 400˚F (opt.)
Adjustment cap Delrin®
(std.); Stainless Steel (opt.)
Length (max.) 10.75”
Length (min.) 9.43”
Diameter 1.75”
Control Connections 1/4” FNPT
Sensing Connection 1/2” MNPT; 1/4” FNPT
Weight 4.1 lb.
Weight (diaphragm model) 6.75 lb.