DEMA 681A-2MS Blend Center Instruction Manual

DEMA 681A-2MS Blend Center

Product Information

The DEMA Model 681A.2P and 681AG.3P Blend Center is a product designed for controlled chemical dilution and dispensing. The product comes with a Blend Center Assembly, Vinyl Outlet Tubing, a Label Card, Vinyl Tubing, Foot Valve, and Ceramic Weight.
It is important to adhere to all warnings and cautions identified in the installation instructions. Installations must conform to all local and national plumbing codes and use approved backflow prevention and pressure relief devices where required.
The product is designed to be used with chemicals, and it is important to always read SDS for all chemicals used and follow personal protective guidelines.

Product Usage Instructions

• Step 1: Chemical Supply
• Place the chemical containers in a convenient location not more than 6 feet below the blend center. Insert the vinyl supply tubing with the foot valve ends into the chemical containers. Cut the vinyl tubes to any convenient length that will allow then to extend from the bottom of the chemical container to the proportioner inlet barbs. Gummed labels are provided for product labeling.
• Step 2: Outlet
• Cut the 9/16 I.D. outlet tubing to the desired lengths and attach them to the proportioner outlets. Longer lengths may be used up to 10 feet. The 7′ long 3/16 I.D. tubing must be left on the 1 GPM proportioner to ensure priming.
• Step 3: Chemical Injection Adjustment
• Chemical feed rates are controlled by metering tips screwed into the proportions barbs. Select a tip for each barb using Table 1 and 2 as a guide. Note: 1 cps (centipoise) is equal to the viscosity of water, 75 cps is approximately equal to the viscosity of 10 weight motor oil, and 200 cps is approximately equal to the viscosity of most dishwashing detergents.
• Servicing
• When servicing the unit, be sure that replacement parts have been installed according to the drawing. If the proportioner fails to draw chemicals, check if the proportioner outlet tubing is cut too short for priming. Pinch the outlet tube to create back pressure which will cause the unit to prime. The foot valve will keep the inlet tube primed thereafter. If there is insufficient water supply pressure, 20 PSI is the minimum allowable. If the proportioned stops drawing chemicals, inspect the foot valve for dried chemical or dirt. Soak in hot water to clean. If the proportioner metering tip is clogged with dried chemicals, remove the tip and try injecting hot water to clear interior passages. If the proportioner continues to draw chemicals after the water valve closes, lower the chemical supply or hang up outlet tubing after use.

PARTS

• A. Blend Center Assembly
• B. Vinyl Outlet Tubing
• C. 1 pc. Label Card
• D. Vinyl Tubing, Foot Valve, and Ceramic Weight
• E. 2 pcs. #8 Pan Head, 1 ¾” Long Mounting Screws & Anchors
• F. Metering Tip Kit

INSTALLATION

This product is designed only to be used as described in this instruction sheet. Adhere to all warnings and cautions identified in this document.

**| WARNING:** Installations must conform to all local and national plumbing codes and use approved backflow prevention and pressure relief devices where required.

**ALWAYS DISCONNECT THE DISPENSER FROM THE WATER SOURCE WHEN THE DISPENSER IS NOT IN USE.**

| Always read SDS for all chemicals used and follow personal protective guidelines.

• A. Mounting and water supply:
• Remove the cover retaining screws and the cover from the blend center assembly. Mount the unit in position on the wall and locate the position for the two screws in the outer most holes in the valve bodies. Mount the unit to the wall and replace the cover and screws. The water inlet is equipped with a female garden hose fitting (with strainer washer) for attaching a water supply hose. The fitting may be removed to permit direct connection to a 3/8” NPT pipe. The unit is designed so water can be supplied to either side by interchanging the pipe plug and the female hose fitting. Note: Apply pipe dope, hand tighten, and then turn 1 ½ times with a wrench. DO NOT OVER TIGHTEN.
• B. Chemical supply:
• Place the chemical containers in a convenient location not more than 6 feet below the blend center (greater lifts will reduce injection capabilities). Insert the vinyl supply tubing with the foot valve ends into the chemical containers. Cut the vinyl tubes to any convenient length that will allow then to extend from the bottom of the chemical container to the proportioner inlet barbs. (See Figure 1). Gummed labels are provided for product labeling.
• C. Outlet:
• Cut the 9/16” I.D. outlet tubing to the desired lengths and attach them to the proportioner outlets. Longer lengths may be used up to 10 feet. The 7’ long 3/16” I.D. tubing must be left on the 1 GPM proportioner to insure priming.
• D. Chemical injection adjustment:
• WARNING: USE CARE WHEN HANDLING HAZARDOUS CHEMICALS. Chemical feed rates are controlled by metering tips screwed into the proportioners barbs. Select a tip for each barb using Tables 1 and 2 as a guide. Note: 1 cps (centipoise) is equal to the viscosity of water, 75 cps is approximately equal to the viscosity of 10 weight motor oil, and 200 cps is approximately equal to the viscosity of most dishwashing detergents.

OPERATION

The Blend Center is now ready for use. Depressing a push button opens the valve, allowing water to flow through the chemical proportioner that mixes chemical at the desired rate. The buttons are spring loaded to prevent accidental overflow if unattended but may be converted to locking buttons by cutting off the tab at the notch. (See Figure 2). Pushing the button and turning it 1/4 turn clockwise at the end of its travel allows the valve to lock on. This makes it unnecessary for the attendant to hold the button in while filling large containers. Turning the button in a counterclockwise direction will release it, allowing the valve to shut off.

SERVICING

CAUTION: TURN OFF THE WATER SUPPLY BEFORE SERVICING.

• A. Proportioner fails to draw chemical:

1. Proportioner outlet tubing is cut too short for priming. Pinch the outlet tube to create back pressure which will cause unit to prime. The foot valve will keep the inlet tube primed thereafter.
2. Insufficient water supply pressure. 20 PSI is the minimum allowable.

B. Proportioner stops drawing chemicals:

1. Inspect the foot valve for dried chemicals or dirt. Soak in hot water to clean.
2. Proportioner metering tip clogged with the dried chemical. Remove tip and try injecting hot water to clear interior passages.

C. Proportioner continues to draw chemicals after the water valve closes:

• The chemical supply is higher than the bottom of the discharge tube creating a natural siphon. Lower the chemical supply or hang up outlet tubing after use.

D. Valve malfunction:

• Check that the button moves freely up & down and that a “click” can be heard when the button is pushed and released, indicating that the magnet is activating the plunger properly. Remove cover. To inspect internal parts, unscrew magnet housing and carefully pull off the enclosing tube so as not to drop the plunger, kick-off spring, and spacer. Check for dirt of damage impending plunger and kick-off spring movement. Inspect the diaphragm, making sure the two small pin holes (bleed holes) in the diaphragm convolution are clear to allow the valve to close.
• CAUTION: When servicing unit, be sure that replacement parts have been installed according to drawing.
• Table 1 – 1 64BAG (1 GPM FLOW RATE PROPORTIONER – ¼” BARB AND TUBING)

Metering Tip Color

| Injection Rates For Viscosities Shown
---|---
1 cps| 75 cps| 200 cps
Oz/Gal| Ratio| Oz/Gal| Ratio| Oz/Gal| Ratio
Tan| 1.25| 102 : 1| 0.90| 142 : 1| 0.60| 213 : 1
Orange| 1.70| 75 : 1| 1.20| 107 : 1| 0.80| 160 : 1
Turquoise| 2.15| 60 : 1| 1.55| 83 : 1| 1.10| 116 : 1
Pink| 3.00| 43 : 1| 2.00| 64 : 1| 1.50| 85 : 1
Clear| 3.90| 33 : 1| 2.75| 47 : 1| 1.80| 71 : 1
Brown| 4.55| 28 : 1| 3.00| 43 : 1| 2.00| 64 : 1
Red| 5.80| 22 : 1| 3.60| 36 : 1| 2.30| 56 : 1
White| 7.00| 18 : 1| 4.45| 29 : 1| 2.70| 47 : 1
Green| 7.90| 16 : 1| 5.00| 26 : 1| 3.00| 43 : 1
Blue| 9.80| 13 : 1| 5.75| 22 : 1| 3.30| 39 : 1
Yellow| 14.80| 9 : 1| 7.35| 17 : 1| 3.55| 36 : 1
Black| 20.15| 6 : 1| 8.50| 15 : 1| 3.70| 35 : 1
Purple| 27.80| 5 : 1| 9.80| 13 : 1| 3.80| 34 : 1
Gray| 31.60| 4 : 1| 10.50| 12 : 1| 3.90| 33 : 1
No Tip| 35.70| 3.6 : 1| 11.80| 11 : 1| 4.50| 28 : 1

Table 2 – 164AG (1 GPM FLOW RATE PROPORTIONER – 3/8″ BARB AND TUBING)

Metering Tip Color

| Injection Rates For Viscosities Shown
---|---
1 cps| 75 cps| 200 cps
Oz/Gal| Ratio| Oz/Gal| Ratio| Oz/Gal| Ratio
Clear| 1.40| 91 : 1| 1.00| 128 : 1| 0.85| 151 : 1
Purple| 2.15| 60 : 1| 1.75| 73 : 1| 1.40| 91 : 1
Yellow| 4.00| 32 : 1| 3.25| 39 : 1| 2.80| 46 : 1
Green| 6.70| 19 : 1| 5.40| 24 : 1| 4.50| 28 : 1
Pink| 8.70| 15 : 1| 7.00| 18 : 1| 5.60| 23 : 1
Turquoise| 14.15| 9 : 1| 11.15| 11 : 1| 8.15| 16 : 1
Black| 17.25| 7 : 1| 13.50| 9 : 1| 10.00| 13 : 1
Gray| 22.60| 6 : 1| 16.75| 8 : 1| 11.60| 11 : 1
Red| 25.15| 5 : 1| 19.50| 7 : 1| 13.50| 10 : 1
Blue| 27.50| 4.7 : 1| 21.65| 6 : 1| 14.25| 9 : 1
Brown| 31.00| 4 : 1| 24.25| 5 : 1| 15.60| 8 : 1
White| 33.50| 3.8 : 1| 26.25| 4.9 : 1| 16.70| 7.7 : 1
Orange| 35.40| 3.6 : 1| 28.00| 4.6 : 1| 17.40| 7.4 : 1
Lt. Blue| 36.50| 3.5 : 1| 29.00| 4.4 : 1| 18.20| 7 : 1
Tan| 37.80| 3.4 : 1| 29.90| 4.3 : 1| 18.65| 6.9 : 1
No Tip| 38.30| 3.3 : 1| 30.90| 4.1 : 1| 21.30| 6 : 1

Table 3 – 163BAG (4 GPM FLOW RATE PROPORTIONER – ¼” BARB AND TUBING)

Table 4 – 163AG (4 GPM FLOW RATE PROPORTIONER – 3/8″ BARB AND TUBING)

Metering Tip Color

| Injection Rates For Viscosities Shown
---|---
1 cps| 75 cps| 200 cps
Oz/Gal| Ratio| Oz/Gal| Ratio| Oz/Gal| Ratio
Clear| 0.90| 142 : 1| 0.30| 427 : 1| 0.20| 640 : 1
Purple| 1.10| 116 : 1| 0.50| 256 : 1| 0.40| 320 : 1
Yellow| 1.80| 71 : 1| 1.00| 128 : 1| 0.70| 183 : 1
Green| 2.50| 51 : 1| 1.50| 85 : 1| 1.20| 107 : 1
Pink| 3.00| 43 : 1| 2.00| 64 : 1| 1.50| 85 : 1
Turquoise| 4.50| 28 : 1| 3.15| 41 : 1| 2.30| 56 : 1
Black| 4.80| 27 : 1| 3.75| 34 : 1| 2.80| 46 : 1
Gray| 6.70| 19 : 1| 4.80| 27 : 1| 3.35| 38 : 1
Red| 8.15| 16 : 1| 5.80| 22 : 1| 3.80| 34 : 1
Blue| 9.20| 14 : 1| 6.60| 19 : 1| 4.20| 30 : 1
Brown| 11.10| 12 : 1| 7.75| 17 : 1| 4.70| 27 : 1
White| 13.20| 10 : 1| 9.15| 14 : 1| 5.00| 26 : 1
Orange| 15.00| 9 : 1| 10.10| 13 : 1| 5.30| 24 : 1
Lt. Blue| 16.70| 8 : 1| 11.10| 12 : 1| 5.50| 23 : 1
Tan| 18.50| 7 : 1| 11.30| 11 : 1| 5.80| 22 : 1
No Tip| 19.40| 6.6 : 1| 13.00| 10 : 1| 6.20| 21 : 1

Note: All induction rates are based on a water pressure of 40 PSI.

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.

INSTALLATION INSTRUCTIONS

ALL INFORMATION CONTAINED IN THIS DOCUMENT IS RELEVANT TO DEMA’S 681 BLEND CENTERS REGARDLESS OF QUANTITIES SHOWN FOR STATION SETUP

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