TriangleTube Prestige Cascade System User Manual
Page 30
27
SECTION VI – SYSTEM PIPING
Multiple Distribution Manifolds
The maximum number of boilers that can be piped in
series is five. If installing more than five boilers you will
need to install the boilers in banks of no more than 5 boil-
ers per bank. The multiple banks should only consist of
Primary Secondary Cascade Kits to ensure adequate flow
through boilers. The system piping between these boiler
banks should be piped in parallel, see Figure 29, page 31.
The parallel system piping between banks may require a
balancing valve(s) if installing an uneven number of boil-
ers per bank (i.e. 4 boiler bank, with a 2 boiler bank), see
Figure 30, page 32.
System Piping
The system piping must be a “closed” system to
avoid any oxygen contamination and potential fail-
ure of the Cascade.
1. The minimum recommended system iron pipe size is
listed in Table 9. This table provides the individual
boiler and system flow rates at various system tem-
perature differences. This table also lists system pip-
ing pressure drops per 100 feet of system piping.
2. To determine the system pressure drop, calculate
the total equivalent length (T.E.L.) of pipe for each
valve and fitting in the system piping in the appro-
priate pipe size using Table 10 page 28. Add the
T.E.L. to the actual straight length of system pipe
of the same size.
3. Once you have calculated the T.E.L. of system pipe
based on a specific pipe size, multiply it by the pressure
NOTICE
drop/100 feet listed for the pipe size to establish the total
circuit pressure drop for that pipe size. If using various
pipe sizes in the system, you will need to do this calcula-
tion for each pipe size separately and add the total pres-
sure drops of all sizes to get a total system pressure drop.
When sizing the system piping and components, it’s
recommended to use a minimum flow rate of 11 gpm
per Solo 250 boiler or 19 gpm per Solo 399 boiler in the
cascade to limit the flow velocity to 4 feet/second and
the friction loss (pressure drop) to 4.2 feet/100 feet of
pipe. Size system piping and components using
approved/recognized design methods, if necessary con-
tact Triangle Tube Technical Support for assistance.
It is recommended to utilize a primary/secondary
Cascade when the total system flow rate is greater
than 22 gpm per Solo 250 boiler or 38 gpm per Solo
399 boiler or less than 11 gpm per Solo 250 boiler or
19 gpm per Solo 399 boiler. A primary/secondary
Cascade is also recommended when the system flow
rate and pressure drop are unknown.
See Figure 31, page 33 for P/S Cascade system piping.
See Figure 32, page 34 for R/R Cascade system piping.
To avoid potential contamination of the boiler piping
and heat exchangers. Install optional strainer kit,
PSCAS24 on the system return piping to boilers in any
R/R Cascade application (with or without boiler valves).
NOTICE
BEST PRACTICE
NOTICE
CSD-1 Piping & Control Installation
Table 9: Minimum Recommended System Iron Pipe Size and Pressure Drop/100 Feet of Pipe
Individual Boiler
or Cascade Kit
P/N
Total Output
MBH
System Temperature Difference (F)
20
30
40
GPM
Iron Pipe
Size
∆P/100
Feet
GPM
Iron
Pipe
∆P/100
Feet
GPM
Iron
Pipe
∆P/100
Feet
Solo 250
223
22
1.5”
3.4
15
1.25”
3.5
11
1.25”
2.0
Solo 399
379
38
2”
2.8
25
1.5”
4.2
19
1.5”
2.6
C(PS or RR)500
446
45
2”
3.5
30
2”
1.8
22
1.5”
3.4
C(PS or RR)800
758
76
3”
1.4
51
2.5”
1.9
38
2”
2.8
C(PS or RR)1000
892
89
3”
1.9
59
2.5”
2.5
45
2”
3.5
C(PS or RR)1200
1,138
114
4”
0.8
76
3”
1.4
57
2.5”
2.5
C(PS or RR)1600
1,518
152
4”
1.4
101
3”
2.5
76
3”
1.4
C(PS or RR)2000
1,897
190
4”
2.1
126
4”
1.0
95
3”
2.2