(PLEASE ALLOW 2 WEEKS BEFORE SHIPPING OF THIS ITEM)1:4 Ratio Factory Direct Replacement Amplifying Relay (Robertshaw)
The Model CR100 Series A and B Ratio Relays comprise a
group of proportioning units designed for use in industrial
pneumatic control systems where the application requires
amplifying or reducing the volume of control air in a
pre-determined ratio. They are available in input to output
ratios of 1:1.5 through 1:6 and 1.5:1 through 6:1. The relay
components are made of steel and aluminum, and the
diaphragms are Buna-N on nylon.
Other features include:
•Fully pneumatic, eliminating any explosion hazard
•Available in a wide variety of input and output pressures
•Functions include addition, subtraction, multiplication, biasing and reversing
•Relay components are made of stainless steel and aluminum
•Diaphragms are Buna-N, nylon-reinforced
Specifications:
Input Pressure Range:
25 psig (1.8 bar) maximum for amplifying
90 psig (6.3 bar) maximum for reducing
Supply Pressure:
60 psig (4.2 bar) maximum (should always be at least
10 psig [0.7 bar] greater than output pressure.)
Output Pressure:........................50 psig (3.5 bar) maximum
Action:................................................................ Proportional
Ambient Temperature Limits:
-40
• F. to 180
• F. (-40
• C. to 82
• C.)
Connections: .............................................. 1/4" female NPT
(Exhaust connection is 1 / 16" female NPT)
Weight: ......................................................1.0 lb. (0.45 Kg.)
PERFORMANCE DATA
Ultimate Sensitivity: .............................. 0.1% of full range
Supply Pressure Effect: ........Change in output pressure for
5 psig (0.35 bar) supply pressure change, less than 1%
of full range.
Ambient Temperature Effect: ........ Change in output for a
75 F. (24
• C.) ambient temperature change - 0.5% of full
range.
Air Consumption: Maximum .............................. 7.0 SCFH
For Maximum Flow:
Supply output capacity .....................3.0 SCFM nominal
Exhaust output capacity ..................5.0 SCFM nominal
OPERATION
The output pressure is proportional to the input pressure as
the effective area of the input diaphragm is to the effective
area of the output diaphragm.
Air pressure in the input chamber exerts a downward force
on the diaphragm. This force moves the center assembly
down, closing the exhaust valve. Further movement opens
the lower portion of the valve allowing the supply air
pressure to enter the output chamber. This air acts on the
diaphragm and also passes out through the output port.
Since the effective area of the input diaphragm, in this case,
is six times as large as the effective area of the output
diaphragm, it will take six times as much output pressure to
balance the unit. As the increasing output pressure
approaches the balance point, the center assembly will
begin to rise, permitting the valve to close, throttling the
flow of supply air. When the output pressure balances the
input pressure, both surfaces of the valve will be closed and
the relay will be in balance.
A further increase in the input pressure will cause the lower
portion of the valve to open until the output pressure again
equals the input pressure. A decrease in input pressure will
allow the output pressure to force the center assembly
upward, opening the exhaust valve until the output pressure
is equal to the input pressure.
TYPICAL APPLICATION
Increase signal range from controller to control valve
which requires higher pressure at valve.
Replaces Part Numbers:
CR-101-A4
CR101-A4
CR101A4
CR100-A4
CR100A4
CR-100-A4
CARCR100A4