Air / Oil Ratiotrol – 7052
Enquiry
Axis Air/Oil Ratiotrol –7052 proportions oil flow to combustion air flow in cross-connected control systems. Outlet oil pressure from the ratiotrol is proportional to the impulse air signal:
7052-01: Outlet pressure is 10 times impulse pressure.
7052-0: Outlet pressure is 12 times impulse pressure.
As combustion air is turned up or down, the ratiotrol causes oil to follow it in proportion. The desired air/oil ratio is set with a manual valve (1813 Sensitrol Oil Valve) at the burner.
Multiple Burners
A single Ratiotrol can serve multiple burners when it is cross-connected downstream of the zone air control valve, provided the burners are on one side of the furnace and the difference in their elevation is less than 12”.
| Ratiotrol | 0.5 PSI | 0.75 PSI | 1 PSI | 1.5 PSI |
|---|---|---|---|---|
| 7052-01 | 194.7 | 237.18 | 276.12 | 336.3 |
| 7052-01-V | 127.44 | 159.3 | 184.08 | 223.02 |
| 7052-0 | 569.94 | 697.38 | 803.58 | 969.96 |
| 7052-0-V | 357.54 | 435.42 | 502.68 | 605.34 |
Expansion Chambers
If the ratiotrol is in a light oil line between valves that are closed when burners are shut off, radiant heat from the furnace could expand oil trapped in the line, bursting ratiotrol diaphragms and damaging gauges. Install one or more 8521-01 expansion chambers downstream of the ratiotrol to prevent this.
| Inlet Oil Pressure | 25–30 PSI (important for proper operation) |
| Maximum Oil Temperature | 180°F for standard 7052 | 300°F for 7052-0-V (with Viton diaphragms) |
| Oil Grades — 7052-01 | Light oil only |
| Oil Grades — 7052-0 | #1 through #6 — heavier oils probably require special construction and other provisions (e.g. Viton diaphragms) |
| Optional Gauges — 7052-01 | Inlet and outlet pressure, air impulse pressure, dial thermometer |