DEMA 481-2 Installation Instructions

DUAL METERING KNOB WITH SOLENOID VALVES
The 481-2 is a dual feed metering knob made of PVC that allows conversion of any single feed "B: or "C" series injector into a dual feed
model. The chemical product going to each hose barb feed is regulated by a color coded metering tip screwed into the end of the barb. The
chemical flow is turned on and off by solenoid valves which allows products to be fed either separately or simultaneously.
The solenoid valves can be specifies to meet you electrical requirements and for either EP (ethylene propylene or Viton® diaphragms. The
only metal the chemical comes into contact with is the stainless steel spring in the check valve. Everything else (the PVC body and Viton®
or EP diaphragms) is impervious to most chemical product.
FLUIDS:
Valves are intended for water, air, light oil, and other noncorrosive fluids. They should not be used for gasoline and other
hazardous or explosive fluids. Maximum fluid temperature is 200 F (93.3 C). Ambient temperature shall not exceed
120 F (48.8 C).
WARNING: NOT FOR USE WITH HAZARDOUS OR CORROSIVE OR EXPLOSIVE FLUIDS.
1. PARTS CHECKLIST:
ITEM DEMA NO.
481-2
A.
2. INSTALLATION:
Installation is as simple as removing the four screws holding the single feed
metering knob on the injector and replacing it with the 481.2 dual feed
version. Connect electricity to the solenoid coils, making certain that the
supply voltage corresponds to the voltage on the nameplate. The injector
itself may be installed in any position in the water line with the arrow in the
direction of flow. Drop ends of plastic tubing with strainers into fluid
product containers. Cut tubing to convenient length, and slip open end
over the 481.2 hose barbs.
3. OPERATION:
Warning: Use care when handling hazardous chemicals.
See Fig. 1 for location of fine metering adjustment screws. Turn on water supply valve. Turning the current "on" opens the valves to fluid
product. The injector may draw momentarily as the system is filling but normally will stop as the system builds up to full pressure.
Table 1 shows the maximum injection rates for models 203C, 204C, and 206C using metering tips at various viscosities. Table 2 shows the
appropriate pipe size used for each injector.
Water Pressure
PSI BARS
10 .69
20 1.38
40 2.76
60 4.14
100 6.90
I-767
Rev. B-29542
DEMA® MODEL 481-2
INSTALLATION INSTRUCTIONS
DESCRIPTION
Dual inlet, solenoid
operated. Metering knob
Water Flow Operating Range - Gallons per minute/ Liters per minute
Model 203C
0.50 - 3.50 1.89 - 13.24
0.55 - 4.40 2.08 - 16.64
0.70 – 5.40 2.65 – 20.42
0.80 – 6.40 3.03 – 24.07
1.00 - 8.00 3.78 - 30.26
QTY.
1
TABLE 1
Model 204C
2.00 - 6.40 7.56 – 24.21
2.30 - 7.50 8.70 – 28.37
2.90 – 9.50 10.96 – 35.93
3.40 – 11.00 12.86 – 41.61
4.20 - 14.00 15.89 – 52.95
93°C
Model 206C
3.60 - 11.00 13.62 – 41.61
4.20 – 13.00 15.89 – 49.17
5.30 – 17.00 20.05 – 64.30
6.20 - 19.00 23.45 – 71.87
7.70 - 24.00 29.12 – 90.78
Pg. 1 of 3
200°F