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NFPA Vent - HELP!
BASIS: NFPA 68 Standard on Explosion Protection by Deflagration
Venting - 2007 Edition
NOTE: Always begin a new case by retrieving the original file.
Direct entry of data in cells that originally contain tablelookups
could cause functions to be lost, or incorrect calculations. I
format cells requiring entry colored RED;calculated values are
black.
RULES AND LIMITATIONS FOR NFPA 68 DUST MODELS:
Print out using direct EXCEL commands.
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NFPA 68 Standard on Explosion Protection by Deflagration Venting
- 2007 Edition
0.8 P0 1.2 bar-abs1 L/D 6
Allow partial volume1 L/D 6
(calculate vent duct effect last)
Print out using direct Excel commands. This application is
provided by Chemical
No vent ductPanel density 40 kg/m2
Allow partial volume1 L/D 6
Elevated initial pressure
Partial volume
Allow vent ductPanel density 40 kg/m2
0.8 P0 1.2 bar-a
(calculate vent duct effect last)No vent duct
Panel density MT and 40 kg/m2
Panel inertia
Panel inertia
0.2 P0 4 bar-gFull volume deflagration
1 L/D 6(calculate elevated initial pressure effect last)
Vent ducts
0.8 P0 1.2 bar-absPanel density MT and 40 kg/m2
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Model Application
explosion dusts - NFPA Psafety January 2001
NFPA 68 Standard on Explosion Protection by Deflagration Venting
- 2007 Edition NFPA 68 Standard on Explosion Protection by
Deflagration Venting 2007 Edition
1 Service: Project No: Date: 8/1/2009BR 549Dust Handling
Collection1. Service: Project No: Date: 8/1/2009 BR-549 Dust
Handling - Collection
2. Client: Equipment: Building 45 Baghouse Confidential2.
Client: Equipment: Building 45 Baghouse Confidential
Equipment / System Specifics
3 D t
Equipment / System Specifics
PAPER DUST3. Dust:M t i U it I i l U it R f
PAPER DUSTMetric Unit Imperial Unit Reference
4. Pred: 3.522 bar-g 51.06 psig Maximum pressure developed
during a vented deflagration4. Pred: 3.522 bar g 51.06 psig
5 P : 0 250 bar g 3 63 psig
p p g f g
Pressure that activates a vent closure5. Pstat: 0.250 bar-g 3.63
psig Pressure that activates a vent closure
6. Pmax: 8.000 bar-g 116.00 psig Maximum pressure developed in a
contained deflagration6. Pmax: 8.000 bar g 116.00 psig
7 V 25 00 t 882 77 ft
Maximum pressure developed in a contained deflagration
Volume of equipment being analyzed7. V: 25.00 cu meter 882.77 cu
ft Volume of equipment being analyzed
8. L/D Ratio: 4.00 Ratio of height -to- diameter8. L/D Ratio:
4.00
9 K 200 b /
Ratio of height to diameter
D fl ti i d f d t l d9. Kst: 200 bar-m/sec Deflagration index of
a dust cloud
8.2.2 - Venting by Means of Low-Inertia Vent Enclosures .. for
Enclosures L/D 2 & L/D
