Weil-McLain SlimFit Manual page 26

SlimFit
™
commercial condensing gas
Multiple boiler water piping
Figure 24
Piping layout — typical piping for multiple SlimFit boilers, with DHW storage heater (or heaters) direct-piped to
one of the boilers
DHW tanks piped using this arrangement need to be sized for
the required load, with a DHW pump selected to provide a flow
rate through the boiler and tank that is within the allowable flow
rate range listed in Figure 13, page 15 of this manual.
• Use 3" or larger piping for all
connections between boilers and
manifolds.
1 Check valve (each boiler)
2 Isolation valves
3 Strainer (recommended on return line to each
boiler)
4 Multiple boiler manifold (supply) — layout and
size per Figure 12, page 15
5 Multiple boiler manifold (return) — layout and size
per Figure 12, page 15
6 Primary pump
7 Expansion tank (diaphragm type shown)
8 System air eliminator
9 System automatic air vent
26
-
fired water boiler
(continued)
• Follow all sizing guidelines on
page 15. Pumps must provide
flow rates required.
Legend — Figure 24
13 Cold water supply (requires items 10, 11 and 12 as
shown in Figure 21, page 23)
17 Boiler pump (each boiler)
18 System supply
19 System return
20 Boiler relief valve and discharge piping (not shown)
— install per page 14 and all applicable codes
21 Indirect-fired storage water heaters (Weil-McLain
AQUA shown). See water heater manual for DHW
piping.
25 External drain/blowdown valve, when used, ¾"
NPT or larger
27 Flow/check valve in DHW piping
— Boiler Manual
• Use recognized engineering
design practices throughout.
30 Strap system supply sensor to the system pipe
as shown. Place sensor at least 6 pipe diameters,
but no more than 10 pipe diameters, from boiler
supply connection to the system pipe.
36 Secondary connection to boiler manifolds — space
no greater than 8 pipe diameters apart
37 DHW pump
Set the Sola control so the boiler pumps, item 17, operate
on any call for heat, whether heating system or DHW.
Offset the DHW boiler-side supply and return manifolds
as shown so the total run of pipe and fittings to each of
the water heaters is approximately equal.
Part number 550-100-116/0713