Strebel S-WG 100, Installation, Operating And Maintenance Manual, Page: 44 / 125

E09.012.246 Manual S-WG
45
9.3 Cascade systems: assigning pipe codes
With the tables in § 9.4 (from page 47 onwards) the diameters of the several connection pipes can be assessed,
so that there will always be sufficient flow.
For using the tables in a straightforward manner, water heaters and pipes need to be numbered, where water
heater-
1 is the one that‘s situated the furthest away from the tanks. The pipe codes are set as pointed out below:
9.3.1
P
IPE CODES WATER HEATER SIDE
The codes of the piping in the picture are used in the installation tables in section 9.4 to determine the right in-
stallation diameters.
Hot water out
These pipes get codes F1 to FF (where FF = F(last)) ( F for flow )
The hot water connections directly to the water heaters get the next codes:

for an installation containing one water heater:
code FF (see § 9.4.1, pick the table of the corresponding water hea-ter type)

for all cascades of more than one water heater:
code F1 = Ø 54 mm (standard tube 54

1.5)
The (
‘continuous’) hot water pipe that’s connected to this ‘water heater flow pipe’ is numbered after the corres-
ponding water heater:
F1 at water heater-1, F2 at water heater-2, etc.
Cold water in
These pipes get codes R1 to RR (where RR = R(last)) ( R for return )
The return connections directly to the water heaters get the next codes:

for an installation containing one water heater:
code RR (see § 9.4.1, pick the table of the corresponding water heater type)

for all cascades of more than one water heater:
code R1 = Ø 54 mm (standard tube 54

1.5)
The (‘continuous’) return pipe that’s connected to this ‘water heater return pipe’ is numbered ‘reversely’ to the
corresponding water heater:

R1 at water heater-last, R2 at water heater-last but one, etc.
Main connections:
- The main connections from cascade to tank(s) are not called F(number-last) and R(number-last) but FF and
RR.
- For every type of cascade
F1=R1, F2=R2, …, FF=RR.
On the next page the procedure will be summarized

F1 R1 F1 R1 F1 R1 F1 R1
R2 R1 R3
RR
FF
F5 F3 F4
R1 F1
R4
F2
R1
RR R5
F1
F1
R1 F1
R6
F6
R1 F1
F7
R7
1 2 3 4 5 6 7 8