FAFCO Connected Tube CT Series Installation Manual page 16

PHASE I — Site Preparations & Planning Cont'd
Figure 6 | Row Plumbing Movement
A straight line of plumbing can move up 1" for a length of 20ft. Plumbing expansion joints are advised to accommodate this movement. An industry standard method, such
as an offset should be used so that the line can move as needed. Refer to Table 5 for regular PVC joint offset lengths and offset type for a length of pipe. See Appendix C
for alternate methods of accommodating for plumbing movement.
(2X) Straight
Line Plumbing
Fixed
Support
When routing plumbing, consideration should be tak-
en to ensure it will be properly guided so that it
moves as intended. Common practice is to strap
plumbing lines with a galvanized plumbing strap an-
chored by 1 or 2 fasteners. This type of mounting al-
lows for movement perpendicular to the direction of
the strap. If plumbing is strapped parallel to the di-
rection of movement without a means of accommo-
dating it in the line, thermal expasion can tear out
the strapping and cause costly damages. Refer to lo-
cal plumbing codes for proper mounting practices of
PVC.
There are multiple methods of accommodating both
bank and plumbing movement. Figure 7 below ex-
plains some ways of accommodating both bank and
plumbing movement. More details are available in
Appendix C for reference.
Fix-Mounted Panel Fix-Mounted Panel
Figure 7 | Row Plumbing Movement
A bank of 5 Panels from the Fixed Panel can move up to 2.5" from normal temperature fluctuations (1.25" in a single direction). In this case, one
could use two Flexible PVC Hoses to accommodate this movement when the plumbing is strapped as shown. Refer to Table 6 in Appendix C
for recommended Flexible PVC Hoses lengths. In this case, the movement in the bank corresponds to ~1.2" which can also be transposed to an
equivalent of 30ft PVC pipe (Table 5). Additionally, there is a 10ft line of PVC. Adding the two provides 40ft of equivalent length, requiring
13.4" of PVC Hose (sourced from Table 6). Since the plumbing can be mounted as Fixed or Guide supports, an offset may also be useful to
absorb some or all of the movement in the above figure. Refer to Appendix C for more variations of Row Plumbing Movement.
Note: It's also acceptable to use another industry standard method to accommodate for thermal movement. Variations of
these recommendations can be used as long as sufficient movement for a standard temperature range of 80°F is allowed.
Guide
Supports
Length of Pipe
Bank Moves up to 5X
(±1/4") = 2.5"
PVC Pipe
The use of a plumbing offset is a largely common
means of enabling axial growth and shrinkage in long-
er runs of plumbing. By offsetting the plumbing with
90° fittings and strapping it in accordance with Fig-
ure 18 and Table 5 in Appendix C, proper movement
can be allowed to take place without cracking fittings,
tearing out mounting points, and restricting the
movement of a solar system.
Note that this is not the only means of properly ac-
commodating for plumbing and bank movement. In-
dustry standard methods are also acceptable. For
more details on proper plumbing mounting and move-
ment, consult a certified plumbing specialist and local
plumbing codes.
Flexible
PVC
Expansion
Joint
~4ft
~14in
Hose
~10ft
Fixed
Support
(~4ft)
~4ft
Guide
Support
Fixed
Support
®
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