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Combustion air system

CAS-1 and CAS-2 Combustion Air Systems

CAS-1 and CAS-2 For Oil Heating Appliances

The CAS-1 is designed for use on the Beckett AFII Series oil burners and AF/AFG Series oil burner with a combustion air intake. For the purpose of routing combustion air directly to the burner, with the added safety feature of the vacuum relief valve.

The Air Boot models CAS-2B (BECKETT-AF/AFG), CAS-2C (CARLIN-EZ-1/CRD/FRD), and CAS-2W (WAYNE-MSR) are for use only on the designated burner(s), for the purpose of routing combustion air directly to the burner, with the added safety feature of the vacuum relief valve.

The Furnace Boot model CAS-2B-90E is designed for use on the Beckett AFG burners for the purpose of routing combustion air directly to the burner, with the added safety feature of the vacuum relief valve.

WHAT’S THE PURPOSE OF THE VACUUM RELIEF VALVE (VRV)?

The Vacuum Relief Valve is a safety device to guard against combustion problems associated with directly connecting oil burners to the outside. Typical problems can be caused by blockage of the intake termination, icing up of the duct work and effects of leeward side wind on a building. The VRV gate operates on changes in the vacuum pressure generated by the inlet to the oil burner.

How Does VACUUM RELIEF VALVE (VRV) Work?

The VRV gate will remain closed during normal burner operation. During an abnormal operation (i.e., blockage of the intake or change in external building pressures) an increased negative pressure on the intake of the burner causes a reduction in burner air flow. Under this condition the VRV gate opens, stabilizing and maintaining proper air flow to the burner. The VRV gate closes again once the abnormal condition is corrected.

In accordance with NFPA 31 and NFPA 54, an unconfined space is defined as follows: Any space whose volume is equal to or greater than 50 cubic feet per 1,000 BTU (or 20 BTU/Cubic Foot).

Specifications

PART # MODEL FUEL BURNER APPLIANCE INPUT COMPONENTS
46252502 CAS-1 Oil Beckett AFII, NX Riello 40BF Up to 2 gph 4" Intake Air Hood, 4" Vacuum Relief Valve
46268401 CAS-2B Oil Beckett AFG or AF, Carlin EZ-1, CRD, FRD, Wayne MSR Up to 2 gph 4" Intake Air Hood, 4" Vacuum Relief Valve, Field AirBoot
46268402 CAS-2C Oil Beckett AFG or AF, Carlin EZ-1, CRD, FRD, Wayne MSR Up to 2 gph 4" Intake Air Hood, 4" Vacuum Relief Valve, Field AirBoot
46268403 CAS-2W Oil Beckett AFG or AF, Carlin EZ-1, CRD, FRD, Wayne MSR Up to 2 gph 4" Intake Air Hood, 4" Vacuum Relief Valve, Field AirBoot
46376200 CAS-2B-90E Oil Beckett AF and AFG, warm air funaces Up to 1.5 gph 4" Intake Air Hood, 4" Vacuum Relief Valve, FurnaceBoot

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