Product Overview

40
103859-12 - 8/19
MPO-IQ
Installation & Service Manual
Figure 30: Two Pipe Oil Lines
C. TWO PIPE OIL LINES
1. For two piped systems, where more lift is required,
the two-stage fuel unit is recommended. Table
7 (two-stage) and Table 8 (single-stage) show
allowable lift and lengths of 3/8 inch and 1/2 inch
OD tubing for both suction and return lines. Refer
to Figure 30.
2. Follow the oil pump manufacturer’s recommendations
on the proper connections for a two pipe system.
Some manufacturers require the insertion of a bypass
plug.
3. Under no circumstances is a manual shutoff valve to
be located on the return line of a two pipe system.
Accidental closure of the return line will rupture the
oil pump seals.
Lift "H"
(See Fig. 25)
Maximum Length of Tubing
"H" + "R" (See Figure)
3/8" OD
Tubing (3 GPH)
1/2" OD
Tubing (3 GPH)
0' 93' 100'
2' 85' 100'
4' 77' 100'
6' 69' 100'
8' 69' 100'
10 52' 100'
12' 44' 100'
14' 36' 100'
16' 27' 100'
18' --- 76'
Lift "H"
(See Fig. 25)
Maximum Length of Tubing
"H" + "R" (See Figure)
3/8" OD
Tubing (3 GPH)
1/2" OD
Tubing (3 GPH)
0' 84' 100'
1' 78' 100'
2' 73' 100'
3' 68' 100'
4' 63' 100'
5' 57' 100'
6' 52' 100'
7' 47' 100'
8' 42' 100'
9' 36' 100'
10' 31' 76'
11' 26' 100'
12' 21' 83'
13' --- 62'
14' --- 41'
Table 8: Single-Stage Units (3450 RPM) - Two Pipe
Systems
Table 7: Two-Stage Units (3450 RPM) - Two Pipe
Systems
7 Oil Piping (continued)