Crown Boiler PHNTM080 - Page 18

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7. Supporting Pipe - Vertical and horizontal sections of pipe must be properly supported. Maximum support spacing is as
follows:
 • SupportCPVC/PVChorizontallyandverticallyevery4feet.
 • SupportDuraVentPolyprohorizontallynearthefemaleendofeachstraightsectionofpipeandverticallyevery10feet.
 • SupportCentrothermInnouehorizontallyevery39incheswithadditionalsupportsatelbowsandverticallyevery78”.
• Support2”SelkirkPolyuehorizontallyevery30”.Support3”Polyuehorizontallyevery39”.Supportverticalrunsof
 both2”and3”Polyueevery16ft.
Les instructions d´installation du système d´évacuation doivent préciser que les sections horizontales doivent être
supportéespourprévenirleéchissement.Lesméthodesetlesintervallesdesupportdoiventêtrespéciés.Les
instructions divent aussi indiquer les renseignements suivants:
• les chaudières de catégories II et IV doivent être installées de façon à empêcher l´accumulation de condensat: et
• si nécessaire, les chaudières de catégories II et IV doivent être pourvues de dispositifs d´évacuation du condensat.
8. Allowing for Thermal Expansion -
 • ForCPVC/PVCpipedesigntheventsystemtoallow3/8”ofthermalexpansionforevery10ftofCPVC/PVCpipe.
The boiler will always act as an anchor to one end of the vent system. If at all possible, select and install hangers and
wall thimbles so that the vent system can expand towards the terminal. When a straight run of pipe exceeds 20ft and
must be restrained at both ends, an offset or expansion loop must be provided (Figures 7.3a, 7.3b). When a straight
horizontal run of pipe exceeds 20ft and is restrained at one end with an elbow at the other, avoid putting a hanger or
  guidelessthan“Y”inchesfromtheelbowintheadjoiningstraightsection(Figure7.3c).Thermalexpansionttings
are not permitted.
 • WhenproperlyassembledexpansionofPolypro,PolyueandInnoueventsystemsisaccommodatedatthejoints.See
Part VII-F, G & H of this manual for details.
9. Running PVC Vent Pipe Inside Enclosures and Through Walls - PVC vent pipe must be installed in a manner that permits
adequate air circulation around the outside of the pipe:
• Do not enclose PVC venting - Use CPVC in enclosed spaces, even if PVC is installed upstream.
• PVC venting may not be used to penetrate combustible or non-combustible walls unless all of the following conditions
are met:
a. The wall penetration is at least 66 inches from the boiler as measured along the vent.
b. The wall is 12” thick or less
c. An airspace of at least that shown in Figure 7.4 is maintained around the OD of the vent.
If any of these conditions cannot be met, use CPVC for the wall penetration.
10. VentManufacturer’sInstructions – The vent system manufacturer may have additional vent system design requirements.
Readandfollowtheventmanufacturer’sinstructionsinadditiontothoseshownhere.Whereaconictarisesbetweenthe
two sets of instructions, the more restrictive requirements shall govern.