12' x 12' DIFFUSER

12 x 12 DIFFUSER OPERATION
1. Install and submerge diffuser. Diffuser should be parallel to the water surface for best
efficiency. Recommended set up should include a condensate drain line in the gas supply
line at the lowest point of the diffuser manifold as shown in the diagram.
2. The diffuser consists of a diffusing membrane laminated to a support base. The membrane
permits gas flow but resists water flow. Water that has condensed in the gas line can block
the flow of gas through the pores of the membrane. Sometimes, because of impatience with
the delay in obtaining the desired gas flow, there is a risk of increasing the gas pressure to
damaging levels. Excessive pressure can cause membrane delamination. Water should be
drained from the gas line, and on startup sufficient time must be allowed for the gas to force
out any water in the membrane pores.
3. On startup, if the diffuser is dry, allow 30 minutes for the surface to wet.
4. Open condensate drain to remove any water in the gas supply line. Start air or oxygen supply
slowly to allow condensate to purge through the drain and to allow pores of the diffuser to
open.
5. Slowly close condensate drain.
6. Maintain 4 psi at diffuser surface for 10 - 30 minutes. CAUTION: NEVER EXCEED 4 PSI
(111 INCHES OF WATER) DIFFUSER SURFACE PRESSURE DROP (DWP).
7. Adjust flow as required to between 0 and 60 SCFH. Recommended flow is less than 30
SCFH or 14 L/Min. The bubble quality will continue to get better as the material thoroughly
wets. The best bubble quality will be observed about 24 hours after wetting surface and
establishing a consistent flow rate. *See notes below.
Diffuser surface pressure drop is also known as Dynamic Wet Pressure (DWP)
DWP = SP - dPsub - dP0x - dPline
Where;
SP = Air or oxygen supply pressure in inches of water (psi x 27.68 = inches H2O ).
dPsub = Diffuser water depth in inches (top of diffuser to water surface).
dP0x = Orifice pressure drop in inches H2O from table enclosed.
dPline = Pressure drop between pressure gauge and diffuser orifice due to pipe line frictional loss
in inches of water.
For example: If the diffuser is 50 inches below the water surface, the orifice pressure drop is 5
inches of water, and the pressure drop in the line is 2 inches