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S
4
®
ERIES
Install water piping
System water pip ing methods
All piping methods shown in this manual use primary/
secondary connection to the boiler loop. These designs
ensure proper fl ow through the Ultra boiler, for the most
effi cient and reliable operation of the boiler and the heat-
ing system. For other piping methods, consult your local
Weil-McLain representative or see separate Ultra boiler
piping guides.
Circulators
The boiler circulator (Taco 007 for Ultra-80 and -105; Taco 0014 for
Ultra-155, -230, and -299/310; Taco 0013 for Ultra-399) is shipped
loose. Locate it in the return piping, as shown in the appropriate pip-
ing diagram in this manual.
use the boiler circulator in any location other
than the ones shown in this manual. The boiler circula-
tor is selected to ensure adequate fl ow through the Ultra
boiler.
Install the boiler circulator only on the boiler return pip-
ing. This ensures the pressure drop through the boiler
will not cause low pressure in the circulator intake.
Failure to comply could result in unreliable performance
and nuisance shutdowns from insuffi cient fl ow.
Circulator fl ow rate
Size circulators based on the fl ow rate required to achieve the tem-
perature change needed. You can closely estimate temperature rise (or
drop) through a circuit by using the following formula, where TD is
temperature rise (or drop), FLOW is fl ow rate (in gpm), and BTUH
is the heat load for the circuit:
=
:
Consider a system loop for a system with total heating load equal to
210,000 Btuh. The desired temperature drop through the system piping
is 20°F. Then the required fl ow rate is:
=
Circulator head requirement
The circulator must be capable of delivering the required fl ow against
the head loss that will occur in the piping. Determine the pipe size
needed and the resultant head loss using accepted engineering meth-
ods. The simplifi ed pipe sizing here is limited to residential systems,
and does not include systems with fan coil units or radiant tubing.
The following simplifi ed method for pipe and circulator
sizing must be limited to residential applications using
baseboard (fi nned or cast iron), cast iron radiators or
convectors. DO NOT apply for radiant heating, fan coil
units or commercial installations.
10
-
GAS
FIRED WATER BOILER
(continued)
=
— Boiler Manual
Simplifi ed pipe/circulator selection
1. Install the boiler and piping using the recommended
piping layouts beginning on page 12 and in the AD-
VANCED section of this manual.
2. Size the piping and components for each circuit in the
space heating system using Figure 3 .
a. Determine the heating load (Btuh) for each circuit.
b. Calculate the fl ow rate for each circuit using its load.
To use a 20°F temperature drop, just divide the
MBH (1,000's of Btuh) by 10.
Example — Flow for 20°F temp drop with 35,000 Btuh:
FLOW = 35 MBH / 10 = 3.5 gpm
c. Find the pipe size in Figure 3 that has a max fl ow rate just
larger than that required for the circuit.
d. Find the total equivalent length (TEL) of the circuit.
TEL accounts for losses through fi ttings and valves by
using the equivalent length of pipe that would cause the
same head loss. Add these numbers to the measured length
of the circuit to fi nd TEL in feet.
TEL is usually close to 1.5 times the length of
the circuit for residential baseboard, radiator or
convector applications.
e. Measure the length of each circuit from the circulator
outlet back to its inlet. Then multiply this length times
1.5 to get the approximate TEL of the circuit.
f.
Find the head loss for each circuit:
g. NOTE: Size system header piping for the total fl ow of all
connected zones.
3. Example:
a. For a circuit with heating load = 45,000 Btuh (= 45 MBH).
Measured length of circuit is 88 feet.
b. Flow = 45 MBH / 10 = 4.5 gpm.
c. TEL = 1.5 x 88 feet = 132 feet.
d. From Figure 3 , select 1" pipe (max fl ow = 7.1 gpm).
e. Head loss = TEL x 0.04 = 132 x 0.04 = 5.28 feet.
f.
Select a circulator that can deliver at least 4.5 gpm at a
head of 5.28 feet. (Read the NOTICE below.)
To use this method, limit the fl ow through ¾"
fi nned-tube baseboard to 3.9 gpm, or use 1"
baseboard and limit fl ow to 7.1 gpm. If the
total load of the circuit requires more fl ow,
split the circuit into two or more.
Also see Figure 9, page 15 for quick-selection
information for applications using Taco 007
circulators or equivalent for zone piping.
Flow rates for 0.04 feet head loss per foot
of pipe
(140°F water)
Pipe size
MAX Flow rate (GPM)
(inches)
@ 0.04 feet per foot
¾
3.9
7.1
16
24
(feet)
(feet water column)
Pipe size
MAX Flow rate (GPM)
(inches)
@ 0.04 feet per foot
45
75
140
290
Part number 550-100-400/0717
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