DEMA BLEND CENTERS
MODEL 681GAP-2P
INSTRUCTION SHEET
I-795 Pg. 1 of 4
Rev. B-36452 1/5/11
1. PARTS CHECKLIST:
A. Blend Center Assembly B. Vinyl Supply Tubing with Foot Valve
C. Ceramic Weight D. Vinyl Outlet Tubing (For 4 or 1 GPM side)
E. Screw/Anchor Kit F. Label Card G. Metering Tip Kit
* Quantities may vary depending on the model.
2. INSTALLATION:Note: All installations must conform to local plumbing codes and use the approved backflow preventers.
Pressureindicating teeisto beinstalled with existing faucetsaccording to local plumbingcodesin thestateofWisconsinand
any other state that requires the use of a pressure indicating tee. WARNING: Water supply should not exceed 125 psiand
water temperature must not exceed 150°F.
A. Mounting and water supply:
Locate mounting holes on a permanent surface for the Blend Center. Drill all of the holes into the drywall usinga 1/4” diameterbit for
use with the included #10 screw and anchor set. (If mounting the Blend Center to wood and you do not plan to use the included
anchors, drill 1/8” diameter holes.) Insert the anchors into drilled holes and hammer them into the wall until theyareflushwithfaceof
wall. Assemble all of the #10 screws with a Phillips screwdriver into the anchors so the screw heads are sticking out of the wall
approximately ½”. Mount the Blend Center byinserting the screw heads through the keyhole slots in the base and tighten the screws.
The water inlet is equipped with a female garden hose fitting (with strainer washer) for attaching a water supplyhose. The fittingmay
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 female hose fitting. Note: Apply pipe dope, hand tighten, then turn 1-½ times with a wrench. DO
NOT OVER TIGHTEN. WARNING: Do not use Teflon® tape to seal internal plastic threads as the extra thickness ofthe tape may
cause the plastic to crack. Use a non-welding liquid sealant instead.
B. Chemical supply:
Place the chemical containers in a convenient location not more than 6 feet belowthe blend center (greater lifts will reduce injection
capabilities). Insert the vinyl supply tubing with the foot valve ends into the chemical containers. Cutthevinyltubestoanyconvenient
length that will allow the tubing to extend from the bottom ofthe chemical container to the proportioner inlet barbs. (See Figure 1)
Gummed labels are provided for product labeling.
C. Outlet:For 4 gpm proportioner, cut the ½” ID X 6’ Lg. tubing to the desired length and attach it to the proportioner outlet barb. Do
not slide tubing pass the first three barbs. For 1 gpm proportioner, do not cut the ½” ID X 6’ Lg. tubing.
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 using Tables 1 and 2.
1 cps (centipoise) is equal to the viscosity of water
75 cps is approximately equal to the viscosity of 10 weight motor oil
200 cps is approximately equal to the viscosity of most dishwashing detergents
TABLE 1 - 1 GPM FLOW RATE PROPORTIONER, 1/4” I.D. TUBING
Injection Rates For Viscosities Shown
1 cps 75 cps 200 cps
Metering Tip Color
Oz/Gal Ratio Oz/Gal Ratio Oz/Gal Ratio
Tan 1.03 125-1 0.76 168-1 0.38 333-1
Orange 1.24 103-1 0.98 130-1 0.53 241-1
Turquoise 1.43 89-1 1.07 119-1 0.61 211-1
Pink 2.47 52-1 1.58 81-1 0.92 139-1
Light Blue* 3.05 42-1 2.1 61-1 1.06 121-1
Brown 3.48 37-1 2.31 55-1 1.15 111-1
Red 4.38 29-1 2.83 45-1 1.23 104-1
White 5.33 24-1 3.1 42-1 1.37 93-1
Green 6.38 20-1 3.63 35-1 1.4 91-1
Blue 6.77 19-1 3.78 34-1 1.45 88-1
Yellow 9.90 13-1 5.1 25-1 1.48 86-1
Black 15.00 9-1 6.54 20-1 1.53 84-1
Purple 24.94 5-1 7.28 18-1 1.57 82-1
Gray 35.94 4-1 8.5 15-1 1.64 78-1
No Tip 73.21 2-1 9.35 14-1 1.87 69-1
*Metering tip color was formerly clear.All induction rates are base on a water pressure of 40 psi.
3. OPERATION:
The Blend Center is now ready for use. Pressing a push button opens the water valve, allowing flow throughthechemicalproportioner that
mixes chemical at the desired rate. The buttons are spring loaded to prevent overflow if unattended, but may be converted to locking
buttons bycutting offthe 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. Turning the button in a counter-clockwise direction will release it, allowing the valve to shut off.
