Crown Boiler FWZ Series, Руководство по установке

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Table 8.0 Minimum Flow Rate Requirements
Model
Minimum Flow
(Approx 35F Rise)*
Flow at 20F Rise
(a) (c) (d) (e)
Min. Flow
(Gal /Min)
Boiler Head
Loss (ft w.c.)
Flow
(GPM)
Boiler Head
Loss (ft w.c.)
FWZ060 4.5 0.10 7.3 0.22
FWZ080 6.0 0.16 9.7 0.38
FWZ081 8.0 0.27 9.9 0.40
FWZ100 8.0 0.27 12.3 0.61
FWZ130 10.0 0.42 16.0 0.88
FWZ160 12.0 0.61 19.7 1.45
* Approximate 25°F Rise for FWZ081
5) Fill Valve (Required) - Either a manual or automatic fill valve may be used. The ideal location for the fill is at the expansion
tank.
6) Automatic Air Vent (Required) - At least one automatic air vent is required. Manual vents will usually be required in other
parts of the system to remove air during initial fill.
7) Low Water Cut-Off (Required in some situations) - A low water cut-off is required when the boiler is installed above
radiation. In addition, some codes such as ASME CSD-1, require low water cut-offs. Codes may also require that this low
water cut-off have a manual reset function. The low water cut-off may be a float type or probe type, but must be designed
for use in a hot-water system. The low water cut-off should be piped into the boiler supply just above the boiler with no
intervening valves between it and the boiler. Use a low water cut-off that breaks the 120 VAC supply to the boiler. Do not
attempt to wire a 24-volt low water cut-off into the boiler factory wiring.
8) 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.
9) 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 “ghost flows” in circulator zone systems through zones that are not calling for
heat.
10) 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.
11) Drain Valve - The drain valve is shipped in the boiler parts bag. Install it in the bottom-rear of the boiler return as shown in
Figure 8.1.