Control Products TYPE 20 HR User Manual
TYPE 20 PRECISION AIR RELAY
FEATURES
• Extreme accuracy
• Positive and negative
bias capability (±30 psig)
• Small size
• Rugged and stable
DESCRIPTION
The Type 20 Air Relay is a compact, two-stage, pilot operated 1:1 relay
with positive and negative bias adjustment capability. It accepts a signal
pressure and combined with the bias adjustment, maintains a resulting
output pressure with an accuracy and reliability unmatched by any other
pressure relay in its price range.
OUTPUT
MODELS
TYPE 20 - The basic relay is offered with a
choice of three port sizes.
TYPE 20HR & TYPE 20EXHR- High Relief
Relays - These relays provide extra fast
“blowdown” for very rapid release of output
pressure. The extra relief feature makes
this relay suitable for cylinder return stroke
actuation, air hoists, and similar applications requiring fast exhaust.
TYPE 20HF tions where the supply pressure is relatively low and a high flow rate is desired.
This relay is ideal for applica
PRESSURE
psig BAR
56 3.9
55 3.8
54 3.7
-
53 3.6
0.0
SCFM
LPM 0 60 115 170 225 280 340 400 450 510
FORWARD FLOW
Type 20, 20HR & 20EXHR
Flow Curve
@ 100 psig (6.9 BAR) Supply Pressure
10.0 12.0 14.0 16.0 18.0
2.0
4.0
6.0
8.0
APPLICATIONS
• Gate Actuators
•Air Hoists
Disc & Shoe Brakes
•
• Remote Positioning Devices
• Valve Rotors
• Control Valves
• Tensioning Systems
• Web Tracking Systems
FEATURES
• Four adjustable positive bias ranges, from
0-10 psi (0-0.7 BAR) to 2-150 psi
(0.1-10.3 BAR)
• Flow capacity up to 50 SCFM
• Quick response to minute changes in
downstream pressure
• Dampening action of aspirator tube
maintains stable output pressure
• Output virtually unaffected by changes in
supply pressure
• Internal rolling diaphragm designed for millions of cycles
• Honking and buzzing eliminated by action of integral baffle and aspirator tube
• Can be disassembled and serviced without removing from line.
DESCRIPTION
The Type 72 Relay features an adjustable bias pressure which enables users to obtain an output pressure which is the sum of a controlled input signal pressure plus the bias. The relay offers
an exceptionally high flow capacity (up to 50 SCFM/1400 LPM) with minimal pressure droop.
Output pressure is accurately maintained under varying flow conditions by means of an
aspirator tube, which adjusts the air supply valve opening in proportion to flow velocity.
A balanced supply valve utilizing a rolling diaphragm makes the relay virtually immune to changes
in supply pressure. Simple design makes
maintenance easy, and the relay can be
serviced without removing it from the line.
The standard signal-to-output ratio is 1:1,
but 1:2, 1:4 and 1:6 ratios are available on
special request. The Type 72HR is available
for applications that require extra fast “blowdown” for rapid release of output pressure.
OUTPUT
PRESSURE
psig BAR
90.0 6.2
80.0 5.5
70.0 4.8
60.0 4.1
50.0 3.4
40.0 2.8
30.0 2.1
20.0 1.4
0.7
10.0
00
SCFM 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0
LPM
FORWARD FLOW
300
0
Type 72 Flow Curves
@ 100 psig (6.9 BAR) Supply Pressure
575
850
1150 1400 1700 2000 2550 2550
TYPE 72 POSITIVE BIAS BOOSTER RELAY
APPLICATIONS
The Type 72 Relay is used when high
flow capacity is required in conjunction with a positive output pressure
bias. Typical applications include:
• Gas Flow Control
• Tensioning Control
• Clutch & Brake Controls
oosting
B
olume
V
•
• Dancer Roll Loading
Calendar
•
Cylinder Bucking Control
•
• Valve Motor Loading
www.marshbellofram.com
Roll Loading
800-727-5646
•