Weil-McLain ULTRA Oil 3 Series Manual page 15

Series 3
Connect water piping
DIAPHRAGM expansion tank (Figure 6)
• Make sure expansion tank size will handle boiler
and system water volume and temperature. Tank
must be located near boiler before inlet to circulator.
See tank manufacturer's instructions for details. See
Replacement Parts page 36 for circulator replacemnt
part numbers.
Undersized expansion tanks cause sys-
tem water to be lost from relief valve and
makeup water added through fill valve.
Eventual section failure can result.
CLOSED expansion tank (Figure 7)
• Ensure expansion tank size will handle boiler and
system water volume and temperature.
Undersized expansion tanks cause sys-
tem water to be lost from relief valve and
makeup water added through fill valve.
Eventual section failure can result.
• Pitch any horizontal piping up towards tank 1 inch
per 5 feet of piping.
Part number 550-143-013/0621
water boiler — Boiler Manual
(continued)
Figure 6
Figure 7
Near-boiler piping, with diaphragm expansion tank
Near-boiler piping, with closed expansion tank
15