Install Instructions

SP470A AND B PNEUMATIC SWITCHES
Port Identification Tables
CAUTION
The following tables identify the ports of older pneumatic
To prevent damage to the sharp barb
relays when upgrading installation.
connections, do not attempt to cut or pull
tubing. To remove the tubing from the barb
Table 1. Port Marking for Three-Position Switch.
connections, cut tubing a few inches from the
control device. Use a coupling to reconnect
tubing.
NOTES: If the system is other than copper or polyethyl-
ene tubing, adapt as shown in Fig. 7. Some
models provide parts for adapting 5/32 in.
(4 mm) barbs to 1/4 in. (6.35 mm) O.D. plastic
SP470
SP74D
SO74D
SO48B SP401
Position 1 7-9 1-2 1-2
Position 2 8-7 2-Vent 1-3
Position 3 6-7 1-3 1-4
or copper tubing.
Table 2. Port Marking for Two-Position Switch.
1 2 3
SP400 SP400 SP400
SP47B SO400 SP47C SO400 SP49A SO400
SP470 SO47B SP401 SO47C SP401 SO49A SP401
Position 1 7 to 8 1-3 3-4 1-2 3-4 M Block 3 to 4
6 to 9 2 Blocked 2 Blocked 3 Vented 2 Vented B Vent 2 to 5
Position 2 6 to 7 1-2 2-3 1-3 2-3 M-B 2 to 3
8 to 9 3 Blocked 4 Blocked 2 Vented 4 Vented √ 4 to 5
1Applied to block disconnected port. Block Port 9 of
SP470 for this application.
2Applied to bleed disconnected port. Vent Port 9 of
SP470 for this application.
3Interchange of two lines.
Checkout and Test
The SP470 switching action should turn firmly, but with a
positive detente action. If there is no detente action,
recheck the knob installation for possible interference
with the panel.
Make certain that the piping connections are correct and,
if air is available, confirm that the intended function
occurs.
Compare the knob pointer position with the scale plate
alignment. Slight correction is possible by loosening the
device mounting. The knob attaches to a flatted shaft and
cannot be reset.
ENGINEERING DATA
Specifications
Models:
SP470A: Pneumatic switch only
SP470B: Pneumatic switch mounted on a panel
Operating Pressure (Switch and Pilot) Range:
Normal: 0 to 18 psi (124 psi maximum)
Ambient Operating Limits:
Temperature: 0 to 140°F (-18 to 60°C)
Relative Humidity: 5 to 95%
Maximum Safe Air Pressure: 30 psi (207 kPa)
Air Capacity: 0.175 scfm at 1 psi drop (82.6 ml/s at 7
kPa drop)
Construction: Molded plastic switch body with Buna N
seal disc, molded glass-reinforced nylon shaft
Operation
The SP470 two-position switch is used for circuit
interchange. See Fig. 8. Position 1 connects Ports 7-8
and Ports 6-9. Position 2 connects Ports 7-6 and
Ports 8-9.
The SP470 three-position switch is used for sequential
switching of one port (Port 7) to the other ports (Ports 6,
8, and 9). See Fig. 8. Position 1 connects Ports 7-9 and
Position 2 connects Ports 7-8. Position 3 connects Ports
7-6. The unconnected ports are blocked to air flow.
NOTES: Both switching models bleed to the atmosphere
when the switch is between positions. Thus,
these switches should not be left between
positions.
7
9
6
8
7
9
6
8
7
9
6
8
THREE-POSITION SWITCH
TWO-POSITION SWITCH
7
9
6
8
7
9
6
8
C1887
Fig. 8. SP970A operation.
3 95-7236EF