Weil-McLain UO-5 CV, UO-4 CV Low Firing Rate Baff e, Burner fuel unit, Nozzle and Pump Pressure

Inspect/Prepare Installation Site Prepare the Burner

Low Firing Rate Baff e

The AFG Low Firing Rate Baffle (LFRB) reduces the air flow and pressure. The LFRB is sometimes used for firing rates under 1.00 gph as listed in Table 4. Refer to the appliance manufacturer’s in- structions. Do not omit the LFRB when specified. Omitting the baffle when specified or installing the baffle when not specified could result in impaired burner performance.

Burner fuel unit

yVerify that the burner fuel unit is compatible with the oil supply system. For more details, refer to the pump manufacturer’s instructions provided with the burner.

Attach air tube (if not already installed)

If using a flange and gasket, slide them onto the air tube. Then attach the air tube to the burner chassis using the four sheet metal screws provided. Refer to Figure 4 for details.

Nozzle and Pump Pressure

!WARNING Correct Nozzle and Flow Rate Required

Incorrect nozzles and flow rates could result in impaired combus- tion, under-firing, over-firing, soot- ing, puff-back of hot gases, smoke

and potential fire or asphyxiation hazards.

Use only nozzles having the brand, flow rate (gph), spray angle and pattern specified by the appliance manufac- turer.

Follow the appliance manufacturer’s specifications for the required pump outlet pressure for the nozzle, since this affects the flow rate.

yNozzle manufacturers calibrate nozzle flow rates at 100 psig.

yWhen pump pressures are higher than 100 psig, the actual nozzle flow rate will be greater than the gph stamped on the nozzle body. (Example: A 1.00 gph nozzle at 140 psig = 1.18 gph)

Securely tighten the nozzle (90 torque inch pounds). For typical nozzle flow rates at various pressures refer to Table 5.

Table 4. AFG Reduced Firing Rates (with LFRB)

Burner head type	Low Firing Rate Baffle installed
F0	up to 0.65 gph
F3 or L1	up to 0.85 gph
F4 or F6	up to 0.90 gph
V1	up to 1.00 gph

Table 5. Nozzle Flow Rate by Size

Nozzle f ow rate U. S. gallons per hour of No. 2 fuel oil when pump pressure (psig) is:

Nozzle	125	140 psi	150 psi	175 psi	200 psi
size	psi
(rated at
100 psig)
0.40	0.45	0.47	0.49	0.53	0.56
0.50	0.56	0.59	0.61	0.66	0.71
0.60	0.67	0.71	0.74	0.79	0.85
0.65	0.73	0.77	0.80	0.86	0.92
0.75	0.84	0.89	0.92	0.99	1.06
0.85	0.95	1.01	1.04	1.13	1.20
0.90	1.01	1.07	1.10	1.19	1.27
1.00	1.12	1.18	1.23	1.32	1.41
1.10	1.23	1.30	1.35	1.46	1.56
1.20	1.34	1.42	1.47	1.59	1.70
1.25	1.39	1.48	1.53	1.65	1.77
1.35	1.51	1.60	1.65	1.79	1.91
1.50	1.68	1.77	1.84	1.98	2.12
1.65	1.84	1.95	2.02	2.18	2.33
1.75	1.96	2.07	2.14	2.32	2.48
2.00	2.24	2.37	2.45	2.65	2.83
2.25	2.52	2.66	2.76	2.98	-
2.50	2.80	2.96	-	-	-

Install burner nozzle (if not already in- stalled)

1.Remove the plastic plug protecting the nozzle adapter threads

2.Place a 3/4” open-end wrench on the nozzle adapter. Insert the nozzle into the adapter and fin- ger tighten. Finish tightening with a 5/8” open-end wrench. Use care to avoid bending the burner head support legs or electrodes. If you remove the head to replace the nozzle (type “L1”/“L2” or “V1” heads), carefully reconnect the head to the nozzle adapter, making sure that the head support makes contact with the nozzle adapter shoulder. Refer to Figure 5 or 6.

Page 8 6104BAFG R06