The OVENTROP-"Toc-Duo-3" is a patented combination of a heating oil filter and an oil breather unit for the use in suction operation and for single-line systems with return flow. The breather housing is made of metal and consists of a bracket for wall mounting and a shut-off valve. The float chamber is made of transparent plastic for easy function control. The installation of the oil filter is permitted below and above the oil level. Technical data: - max. flow rate: 110 l / h EL heating oil - max. return flow rate: 120 l / h EL heating oil - ventilation rate: max. 6 l / h air - approval for a bio-degradable share of up to 20% - connections: on the tank side: G 3/8"" IT on the burner side: G 3/8"; ET with inner cone for burner hoses with 3/8" lock nut