Crown Boiler BWF Series Installation Instructions Manual page 24

7. Water Piping (continued)
7. Manual Reset High Limit (Required by some
codes) - This control is required by ASME
CSD-1 and some other codes. Install the high
limit in the boiler supply piping just beyond
the boiler with no intervening valves. Set
the manual reset high limit as far above the
operating limit setting as possible, but not over
240°F. Wire the control to break the 120 VAC
electrical supply to the boiler or the external
limit connection shown in Section 9.
8. Flow Control Valve (Required under some
conditions) - The flow control valve prevents
flow through the system unless the circulator
is operating. A flow control valve may be
necessary on converted gravity systems to
prevent gravity circulation. Flow control valves
are also used to prevent flow in circulator zone
systems through zones that are not calling for
heat.
9. Isolation Valves (Optional) - Isolation valves are
useful if the boiler must be drained, as they will
eliminate having to drain and refill the entire
system.
10. Drain Valve - The drain valve is shipped in the
boiler parts bag. Install it in the tee under the
circulator as shown in Figure 7.3.
24
Figure 7.4: Indirect Water Heater Boiler Side Piping
11. Alternate Return Tapping - An unplugged
1-1/4" return tapping is provided on the left
side of the boiler (see "Piping for Special
Situations" below). Use the nipple and cap
provided to plug whichever return tapping
is not used. Both the supply and return
connections must be made on the same side
of the boiler.
B. Piping For Special Situations
Certain types of heating systems have
additional requirements. Some of the more
common variations follow:
1. "Left Piped" Boilers – If necessary, the supply
and return may be connected to the left side
of the boiler by moving the 1-1/4" plug and
the relief valve fittings from the tappings in
the left side of the boiler to the corresponding
tappings on the right. Both the supply and
return connections must be made on the same
side of the boiler.
109836-01 - 04/20