The table of multipliers above permits ready calculation of the heating capacities of M & L fuel oil heaters when used for oil heating ranges other than those shown as standard in the tables of capacities appearing throughout this bulletin.

M & L standard heating ranges are based on heating oil from 90° to 150° F when using boiler water as the heating medium and 80° to 180° F when using steam from 0 to 150 psi. Proper operation of commercial oil burners may require heating through ranges other than standard. The re-rating of any M & L Heater to the modified ranges can be done, simply by using the "Table of Multipliers".

To obtain the modified capacity of any M & L Heater:

1    Look up the standard capacity in the "Table of Capacities" which lists the proposed heater
2    Look up the multiplier in the "Table of Multipliers" shown opposite the desired heating range and under the proposed heating condition.
3    Required capacity can be secured by multiplying the standard capacity by the multiplier taken from the Table of Multipliers above.

Example:  A 6-pass heater is needed for 88 GPH of No. 6 oil.  Temperature range 80° to l60°F steam at 10 psig.
1    "Table of Capacities" will show for these specifications that M & L Heater No. 454 has a capacity of 65 GPH oil heated 80° to 180° F.
2    "Table of Multipliers" will indicate, opposite 80° to 160° F, heating with 10 pounds steam, that the factor is 1.35.
3    Multiply 65 (standard capacity) x 1.35 (factor) to equal 88 GPH, the new capacity for M & L Heater No. 454 for the oil heating range of 80° to 160° F.

Caution:  When using the "Table of Multipliers" do not exceed pressure drop limitations of the individual heater.  This can be done by limiting the new capacity of any heater to the maximum shown in the "Table of Capacities".
For example:  The largest capacity shown for a No. 354 Heater is 210 GPH.  No capacity, therefore, should exceed 210 GPH for No. 354 Heater because the pressure drop would become excessive.