Waste Oil Heater Forum - Your definitive source for burning waste oil for heat.

Fuel Delivery Styles => Siphon Nozzle => Constant Level Device => Topic started by: dc on December 28, 2013, 10:13:37 pm

Title: why constant level device
Post by: dc on December 28, 2013, 10:13:37 pm
The commercial units do not use one that I now of. But I could be wrong. In my pressure system I do not use one. I only
use a five gallon container to gravity feed my becket oil furnance that I run waste oil through at 25% diesel and 75% waste oil mix.
Title: Re: why constant level device
Post by: Russ on January 02, 2014, 12:36:30 pm
If the holding tank for your waste oil varies, the pressure of the oil to the nozzle will change.  This change in pressure will be small, but can greatly affect a siphon system.  A full holding tank will send more pressure and as the tank empties, the pressure will reduce.  By having the oil enter a CL tank, the level will always be the same, therefore always presenting the same pressure to the siphon nozzle.  Actually you usually want the oil level in the CL tank lower than the nozzle. If it were above, I would imagine the pressure would force oil out the nozzle while the burner was shut down, causing a mess.

I believe the commercial units use a metering pump to deliver a constant and steady flow of oil to the burner.  In a siphon system you either need a CL tank or a metering pump.  Metering pumps can be expensive, so many opt for the CL tank.