D EMA TWO-STAGE INJECTOR MODELS 233, 234A, 236A, 236-8, 238, AND 2312 INSTALLATION INSTRUCTIONS FIGURE 3 FIGURE 2

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1 1. PARTS A. Injector B. Three brass nozzle bushings. C. Plastic Tubing 8 long with foot strainer. D. Ceramic Weight 2. INSTALLATION A. Selecting the nozzle bushing: Refer to Section 4 APPLICATIONS and then use the table to select one of the three bushings supplied. Push the bushing into the injector inlet, small end first, as far as it will go. See Fig. 1. For dishwashing machines, see Table 2. B. Placement in the water line: FIGURE 1 The injector may be installed in a horizontal or vertical line and with the knob in any position below, above, or to the side. Water flow must be in the direction of the arrow on the injector body. If the injector pipe size is different from the line size, use pipe bushings or reducers as required. (Injector selection is based on flow, not line size.) C. Connection to chemical supply: Drop the end of the tubing with the strainer into the fluid product container, cut the tubing to any convenient length and slip the open end over the injector inlet fitting. The container may be more than 8 feet below the injector (extra tubing required) but injection capacity will be less. Do not place the container above the injector unless the injector is under pressure when not in use. This will prevent free siphoning. The metal drum protector disc may be used to cover the container opening and to hold the tubing in place. Twist the disc at the slit for easy application. 3. CHEMICAL FEED ADJUSTMENT See FIG. 1 for the location of the metering screw in the knob. The maximum and minimum injection rates are shown in Table 1. Turn the screw all the way for minimum and 5 turns to the left for maximum rates. Maximum injections are for 8 feet of suction tubing, a lift of 4 feet from the fluid container to the injector and a maximum water temperature of 140 F. Injectors will operate at reduced rates up to 0 F or a lift up to 25 feet. If the viscosity of the fluid to be injected is unknown, compare the following: 1 cps: water 75 cps: SAE motor oil 2 cps: SAE 30 motor oil FIGURE 2 FIGURE 3 SOLENOID VALVE SIPHON BREAKER (REQUIRED BY SOME PLUMBING CODES) SPRAY GUN LINE STRAINER I-1 Pg. 1 of 7

2 4. APPLICATIONS SPRAYING SYSTEM: Select from Table 1 the nozzle bushing to match your total spray nozzle flow and pressure. Spray nozzle catalog flow ratings are the most convenient method of determining water flow. Once an injector has been matched to a spray nozzle system, it will continue to function regardless of fluctuations in line pressure, as the water flow will also fluctuate in proportion. Therefore, if your line pressure is unknown, it is permissible to use spray nozzle ratings at any pressure, for the purpose of selecting an injector. Flow ratings at 40 PSI are the basis for the spray nozzle numbering system and are therefore most frequently used. If there are lengthy piping, hose, valves or other restrictions between the injector and nozzles, these pressure losses must be added to the rated pressure before entering Table 1. MODEL NUMBER MODEL SPRAYING SYSTEM TABLE 1 TOTAL SPRAY NOZZLE GPM SPRAY NOZZLE PRESSURE PSI *MAX. INJECTION OZ/MIN. VISCOSITY- CPS MIN. INJECTION CC/MIN. VISCOSITY- CPS BUSHING A A I-1 Pg. 2 of 7

3 SYSTEM OF UNKNOWN FLOW OR PRESSURE: FIG. 4 If the supply line is large and the injection requirement low, a small injector may be used in a by-pass line. Use the lowest number nozzle bushing supplied with the injector. The hand valve in the main line is throttled until the injector starts to function, thus matching the injector to the unknown capacity of the spray system. If the injector fails to function even with the valve completely closed, a smaller injector must be used. If the water usage changes, such as by opening or closing valves in branch lines beyond the injector, the hand valve must be readjusted, or separate injectors must be installed in the branch lines. FIGURE 4 It sometimes is desired to inject a quantity of chemical in a minimum time without regard to the proportion, such as liquid fertilizer into a lawn sprinkler system or water treatment chemical into a boiler feed line. The hand valve is throttled as much as possible without interfering with operation, or possibly closed completely, until the desired quantity is injected. If periodic injection is required the hand valve could be replaced by a solenoid valve controlled by a time clock. 5. SERVICING: A. If the injector fails to draw chemical in the initial installation: 1. Has the injector been correctly sized to the equipment and the proper nozzle bushing been installed? Review the application in Section 4. Do not neglect line losses. 2. Is the injector body installed with the arrow on the side in the direction of water flow? 3. Is the chemical metering screw backed off? 4. Are the spray nozzles clogged, hose kinked, or is there some other obstruction in the water line? 5. Is the water temperature too high? 0 F is the highest allowable and injection will fall from maximum as temperature rises above 140 F. B. If the injector stops operating after having worked properly: 1. See A-4 above. Clean or remove obstructions. 2. Is the foot strainer clogged? Lift tube from drum and clean. 3. Is the check valve clogged? Unscrew knurled knob with metering screw to disassemble. Inspect and clean ball, spring, and o-ring. 4. Is the internal fine mesh screen clogged? (Except Models 8 and ) To clean the screen unscrew the knurled cage on the injector. Remove the screen and clean. After replacing the cleaned screen make sure the rubber o-rings are in place before screwing the cage back onto the injector. 5. Are there lime deposits in the throat of the injector? Certain chemicals can cause precipitations in the throat of the injector. Let the injector draw in a small quantity of a deliming agent (mild acid) to remove the deposit. If deposits are so heavy that injection has ceased it may be necessary to remove the knurled cage and soak it. Should liming be recurrent, periodic maintenance is indicated. I-1 Pg. 3 of 7

4 RINSE S FOR DISHWASHING MACHINES INSTALLATION LISTED BY NATIONAL SANITATION FOUNTATION See Table 2 for correct nozzle bushing for dishmachines listed by the National Sanitation Foundation. See Figure 5 for correct placement in the final rinse line, as required by most plumbing codes. The NSF Standard No. 3 for commercial spray-tub dishwashing machines specifies a minimum flow pressure of PSI and a maximum of 25 PSI on the line adjacent to the machine. Injectors equipped with the correct bushings will result in water pressure losses as follows: ORIGINAL FLOW PRESSURE PSI 25 PRESSURE LOSS PSI READJUSTED FLOW PRESSURE PSI Therefore, after the injector is installed, the flow pressure entering the machine must be adjusted to not less than PSI and not in excess of 32 PSI. For reference, water capacities are: FIGURE 5 MODEL NO. WATER FLOW GPM NOZZLE PRESSURE LOSS -- PSI BUSHING 5 PSI 6 PSI 7 PSI 3 4A 6A I-1 Pg. 4 of 7

5 TABLE 2 Rinse Injector Models for dishwashing machines listed by National Sanitation Foundation Dishmachine Type (Check List Below For Exceptions) SINGLE TANK MACHINES MULTIPLE TANK MACHINE HOOD TYPE DOOR TYPE CONVEYOR Use DEMA Injector Model/Nozzle Bushing For exceptions, see below ADAMATION 4A/ for A- AUTOMATION D.S.S. BLAKESLEE (Canada) RACK CONVEYE R RACKLESS CONVEYER 6A/17 6-8/ 6A/17 6A/ 6A/ CHAMPION T-7A, T-7AC GENERAL ELECTRIC SKB, SKB SK30B HOBART 6A/ INSINGER JACKSON METOS STERO TOASTMASTER VULCAN-HEART 6A/ 6-8/ for SF-2RA 24B 500 and 5 R-BTA 4A for WR, SWR 6-8/ for XF XF 6A/ for UC-6-IT Anscomatic UC**CW 6A/ for Mini Flite S-9 thru S-, and Admiral RC thru RC 6-8/ for STPCW 6-8/ for TKM Rackless 6A/ for models with suffix EW STPCW TKM 6A/17 I-1 Pg. 5 of 7

6 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. I-1 Pg. 6 of 7

7 NO. PART NO. DESCRIPTION 1-1 CASE ASSEMBLY 2-2 CASE 0-RING, SMALL 3-3 CAGE O-RING, LARGE 4-5 FIRST-STAGE VENTURI 5-8- WATER NOZZLE ADD NUMBER STAMPED ON NOZZLE 6-26S METERING KNOB COMPLETE 7-27 METERING KNOB O-RING CAGE ASSEMBLY P CAGE ASSEMBLY (-P S) 24-2 CAGE O-RING, SMALL 24-3 CAGE O-RING, LARGE 24-4 CAGE SCREEN 24-5 FIRST STAGE VENTURI P FIRST STAGE VENTURI (-P S) NO. PART NO. DESCRIPTION WATER NOZZLE ADD NUMBER STAMPED ON NOZZLE 24- VINYL TUBING (1/2 O.D. X 8 FT LG. 24-MP FOOT STRAINER SP FOOT STRAINER 24- CHECK VALVE SPRING 24-24P CHECK VALVE BALL (-P S) 24-24S CHECK VALVE BALL CHECK VALVE O-RING S METERING KNOB, COMPLETE 24-26SP METERING KNOB, (-P S) VINYL TUBING (1/2 O.D. X 8 FT LG METERING SCREW SP METERING SCREW (-P S) I-1 Pg. 7 of 7