Mike Sullivan
New member
There is a very fine line when operating dual 12V Delavan 5gpm 60psi pumps.
I tried multiple combinations of hose size, length, nozzles, guns and figured out the best combination for running one or two pumps together in tandem.
I talked to Bob with Pressure Tek at the NC round table and he says that the new Delavans are no longer available to adjust to 100psi. They are fixed at 5gpm 60psi.
The most each pump will output under a load (100-200ft 5/8 hose and a #40 nozzle) is 3gpm.
Running 2 pumps together in tandem took some tweaking to get it to double the output to a maximum of 6gpm.
The slightest little bit of restriction whether it be in the hose, gun, filter or nozzle will cause the dual system to bog down and produce less flow than the maximum of 6gpm.
60psi is not enough pressure to push a full 10gpm. If you want a 10+gpm roof rig, get a gas powered setup.
Dual Delavans
Hose: 5/8 works for one pump but not two in tandem. 5/8 hose is too small and will cause the pumps to cycle on and off.
3/4 hose is what you need for the dual setup.
Gun: Regular garden guns are too restrictive, so are the poly guns. Best cheap guns I have found are either the high flow twist guns http://www.lrnelson.com/products/model.cfm?MODEL=151 or
3/4 full port ball valve with adapters to fit a coupler for interchangeable nozzles. Have not tried the expensive accuspray guns.
Filter: Bogs the dual system down too much. No filter recommended.
Nozzles: The #30 or #40 works best for one pump, dual pumps need #60 nozzles.
I tried multiple combinations of hose size, length, nozzles, guns and figured out the best combination for running one or two pumps together in tandem.
I talked to Bob with Pressure Tek at the NC round table and he says that the new Delavans are no longer available to adjust to 100psi. They are fixed at 5gpm 60psi.
The most each pump will output under a load (100-200ft 5/8 hose and a #40 nozzle) is 3gpm.
Running 2 pumps together in tandem took some tweaking to get it to double the output to a maximum of 6gpm.
The slightest little bit of restriction whether it be in the hose, gun, filter or nozzle will cause the dual system to bog down and produce less flow than the maximum of 6gpm.
60psi is not enough pressure to push a full 10gpm. If you want a 10+gpm roof rig, get a gas powered setup.
Dual Delavans
Hose: 5/8 works for one pump but not two in tandem. 5/8 hose is too small and will cause the pumps to cycle on and off.
3/4 hose is what you need for the dual setup.
Gun: Regular garden guns are too restrictive, so are the poly guns. Best cheap guns I have found are either the high flow twist guns http://www.lrnelson.com/products/model.cfm?MODEL=151 or
3/4 full port ball valve with adapters to fit a coupler for interchangeable nozzles. Have not tried the expensive accuspray guns.
Filter: Bogs the dual system down too much. No filter recommended.
Nozzles: The #30 or #40 works best for one pump, dual pumps need #60 nozzles.
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