I-525
Pg. 1 of 2
Rev. A0600
DEMA ADJUSTABLE SINGLE STAGE INJECTORS
MODEL 203BS-2EP
INSTALLATION INSTRUCTIONS
1. PARTS
A. Injector
B. Ceramic Weight.
C. Plastic tubing 8' long with foot strainer.
2. INSTALLATION
The injector may be installed in any position in the water line with the arrow in the
direction of flow. Drop end of plastic tubing with strainer into fluid product container. Cut
tubing to convenient length, and slip open end over injector fitting.
3. OPERATION
WARNING: Use care when handling hazardous chemicals.
See Fig. 1 for location of water bypass screw and fine metering adjustment screw. Turn on
water supply valve. The injector may draw momentarily as the system is filling but
normally will stop as the system builds up to full pressure. To actuate injector, turn the
bypass screw clockwise until product begins to be drawn from the container. After the
fluid reaches the injector, the feed rate may be adjusted to the desired rate by turning the
bypass screw. The maximum injection rates are shown in Table 2. For low injection rates,
it is advisable to set the bypass screw for more injection than required; then turn the fine
metering screw clockwise to reduce injection to the desired rate.
Table 1 shows the operation range of the injector. If the injector will not draw with the
bypass screw full in, then the water flow is below the range of the injector. If the injector
draws with the screw full out but pressure loss is excessive, then flow is above the range of
the injector.
4. SERVICING
CAUTION: Turn off water supply before servicing.
The check valve parts are in the metering knob and can be cleaned by removing the four
screws. The knob may be rotated if it is more convenient to have the adjusting screw on
another side of the injector. As with any injector, if spray jets become clogged or
downstream restriction increases in any manner, the injector will stop drawing fluid. If it is
inconvenient to remove the restriction immediately, the injector may be put back into
operation by turning the water bypass screw further clockwise; this adjusts the injector to
the lower flow rate. The bypass screw should be reset once the restriction is removed.
CAUTION: When servicing, make sure that replacement parts have been installed
according to drawing. Be certain to check valve parts are in place.
TABLE 1
Water Pressure
(psi)
Operating Range -
Gallons Per
Minute
10
0.50 - 3.50
20
0.55 - 4.40
40
0.70 - 5.40
60
0.80 - 6.40
100
1.00 - 8.00
200
1.40 - 11.00
400
1.90 - 15.00
500
2.10 - 17.00
700
2.50 - 20.00
1000
3.00 - 23.00
1500
3.50 - 28.00
2000
4.70 - 37.00
TABLE 2
Fluid Viscosity
(cps)
Maximum
Injection
(Oz/Min)
1
20.0
75
8.0
200
3.7
RETURNS:
NO MERCHANDISE MAY BE RETURNED FOR CREDIT WITHOUT DEMA’S WRITTEN PERMISSION. RETURN
MERCHANDISE AUTHORIZATION NUMBER REQUIRED IN ADVANCE OF RETURN.
WARRANTY:
DEMA products are warranted against defective material and workmanship under normal use and service for one year from the date of
manufacture. This limited warranty does not apply to any products which have a normal life shorter than one year or failure and damage
caused by chemicals, corrosion, improper voltage supply, physical abuse, or misapplication. Rubber and synthetic rubber parts such as “o”-
rings, diaphragms, squeeze tubing and gaskets are considered expendable and are not covered under warranty. This warranty is extended
only to the original buyer of DEMA products. If products are altered or repaired without prior approval of DEMA, this warranty will be
void.
Defective units or parts should be returned to the factory with transportation prepaid. If inspection shows them to be defective, they will be
repaired or replaced without charge, F.O.B. factory. DEMA assumes no liability for damages. Return merchandise authorization number,
to return units for repair or replacement, must be granted in advance of return.
