Crown Boiler PHNTM080 - Page 17

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4. Minimum Vent and Air Intake Lengths - Observe the minimum vent lengths shown in Tables 7.1, 7.13 and 7.21.
5. Clearances to Combustibles - Maintain the following clearances from the vent system to combustible construction:
• Vent - 1/4” (also observe clearances through both combustible and non-combustible walls - see 9 below)
• Air Intake - 0”
• Concentric Portion of Concentric Terminals - 0”
6. Pitch of Horizontal Vent Piping - Pitch all horizontal vent piping so that any condensate which forms in the piping will run
towards the boiler.
 • PitchCPVC/PVCventpiping1/4”perfoot.
 • Pitchpolypropyleneventpiping5/8”perfoot.
LeschaudièresdecatégoriesI,IIetIVdoiventprésenterdestronçonshorizontauxdontlapentemontanteestd’aumoins
5/8poparpied(52mm/m)entrelachaudièreetl’évent.





TABLE 7.1: VENT/ AIR INTAKE FITTING EQUIVALENT LENGTH
CPVC/PVC FITTING EQUIVALENT LENGTH (ft) POLYPRO, POLYFLUE OR INNOFLUE
VENT FITTING
EQUIVALENT LENGTH (ft)
2” 90 ELBOW (“SANITARY BEND”) 2.6 2” 90 ELBOW 4.5
3” 90 ELBOW (“SANITARY BEND”) 4.0 3” 90 ELBOW 8.7
2” 90 ELBOW (“SHORT BEND” ) 6.0 2” 45 ELBOW 2.5
3” 90 ELBOW (“SHORT BEND”) 10.0 3” 45 ELBOW 4.6
2” 45 ELBOW 1.5
3” 45 ELBOW 2.0
2” COUPLING 0.0
3” COUPLING 0.0
FIGURE 7.2: CPVC AND PVC ELBOWS