035-17473-000-B-1101
Unitary Products Group
9
PIPING INSTALLATION
In Canada, the entire fuel system should be installed in
accordance with the requirements of CAN/CSA B-139,
and local regulations. Use only approved fuel oil tanks
piping, fittings and oil filters.
In the United States the installation must be in accor-
dance with the requirements of NFPA No. 31 and local
codes and regulations.
Ensure that all fittings used in a copper oil line system
are high quality flare fittings. Do not use compression
fittings.
Pressurized or gravity feed installations must not
exceed 3 PSIG. A pressure greater than 10 PSIG may
cause damage to the shaft seal. If the height of the oil
stored in a tank above the oil burner exceeds 11-1/2
feet, it may be necessary to use a pressure-regulating
device approved for this purpose.
The P*HMX series furnace may be installed with a one
pipe system with gravity feed or lift. The maximum
allowable lift on a single line system is 8 feet. Lift
should be measured from the bottom (outlet) of the
tank, to the inlet of the burner. Sizing a single line sys-
tem is complex because of the difficulty estimating the
pressure drop through each fitting, bend and compo-
nent in the line. In general, keep single line systems
short as possible. If the furnace is to be installed in a
suspended position, a two pipe system may be the bet-
ter alternative. Two-stage oil pumps are not available
for oil burners featuring the Beckett Clean Cut Fuel
Unit. Table 5 shows the allowable line lengths (horizon-
tal + vertical) for single and two stage oil pumps. All dis-
tances are in feet.
In retrofit applications, where an existing oil line system
is in place, a vacuum check will help determine
whether a 2-stage oil pump is necessary. The vacuum
in a system featuring a single stage oil pump should
not exceed 6” Hg. The vacuum in a system featuring a
2-stage oil pump should not exceed 15” Hg. (inches of
mercury.
For additional information, see the installation informa-
tion sheet affixed to the oil burner).
OIL FILTER
All fuel systems should include an oil filter between the
fuel oil storage tank and the oil burner. For best results,
install the oil filter as close to the burner as possible.
When using an indoor oil tank, the oil filter may be
installed at the tank downstream from the shut-off
valve. If firing the furnace under the 0.65 gph rate, a 7
to 10 micron line filter should be installed as close to
the oil burner as possible.
OIL BURNER NOZZLES
The P-HMX Series furnace is certified for multiple firing
rates, ranging from 58,000 to 120,000 BTU/Hr. By
manipulating the oil burner nozzle, flame retention
head, and temperature rise, the furnace may be fired at
an ideal rate for a wide range of structures.
Table 5: Oil Lines
Copper Tubing Oil Line Lengths
Single Stage
2-Stage
Lift
(feet)
3/8
” O.D.
Tubing
1/2
” O.D.
Tubing
3/8
” O.D.
Tubing
1/2
” O.D.
Tubing
0
53
100
68
100
1
49
100
65
100
2
45
100
63
100
3
41
100
60
100
4
37
100
58
100
5
33
100
55
100
6
29
100
53
100
7
25
99
50
100
8
21
83
48
100
9
17
68
45
100
10
13
52
42
100
12
- - -
- - -
37
100
14
- - -
- - -
32
100
16
- - -
- - -
27
100
18
- - -
- - -
22
88
Table 6: Nozzles
MODEL
NOZZLE (Delavan)
STD
ALT
HEAD
P*HMX12F05701
0.50 / 70° A
0.50 / 80° A
F0
P*HMX12F08001
0.70 / 70° A )
0.70 / 80° A )
F0
P*HMX14F10001
0.80 / 70° A
0.80 / 80° A
F3
P*HMX20F12001
1.00 / 70° A)
1.00 / 80° A)
F3
