nfpa 13 2010 changes in a nutshell
TRANSCRIPT
What’s New in NFPA 13 – 2010(That I can cover in 30 minutes)
Kenneth E. Isman, P.E., F.S.F.P.E.Vice President of Engineering
Outline• Seismic Load Tables• Shortened Density-Area Curves• High Clearance for Storage• New Discharge Rules for Specific Situations
• Back-to-Back Shelf Storage• Record Storage in Racks• Compact Storage• High-Bay Record Storage
• Darcy-Weisbach Friction Loss for Antifreeze
Seismic Load Tables
• 2007 – Load tables added for Schedule 10 and Schedule 40 steel
• 2010 – Load tables added for other types▫ Schedule 5 steel pipe▫ CPVC pipe▫ Type M copper tube
Seismic Load Tables
• Other types of pipe with different wall thicknesses▫ Use the tables in NFPA 13 for the same
pipe material with a thinner wall; or▫ Use Manufacturer’s Tables
Seismic Load Tables
Seismic Load Tables
Shortened Density-Area Curves
• No change to Chapter 11 (light, ordinary and extra hazard curves)
• For high-piled storage ▫ 2000 ft2 (186 m2) through 3000 ft2 (279 m2)
• For miscellaneous storage▫ 1500 ft2 (139 m2) through 3000 ft2 (279 m2)
General Storage Density/Area Curves
Former
New
Rack Storage Density/Area Curves
Former
Rack Storage Density/Area Curves
New
A BC D E FG H J
I
High Clearance above Storage
• Solid Piled Storage▫ 12.1.3.4.2▫ Where the clearance exceeds 20 ft (6.1 m)▫ Base protection on the storage height that would
result in a 20 ft (6.1 m) clearance
▫ Example: 15 ft storage in 40 ft high building▫ Design sprinkler system for 20 ft storage
High Clearance above Storage
• Rack Storage ≤ 25 ft (7.62 m) in height Class I-IV▫ 12.1.3.4.3▫ Where the clearance exceeds 20 ft (6.1 m)▫ Base protection on the storage height that would
result in a 20 ft (6.1 m) clearanceOR▫ Provide one level of supplemental, quick-response
in-racks sprinklers located directly below the top tier of storage at every flue space intersection.
High Clearance above Storage• Rack Storage > 25 ft (7.62 m) Class I-IV & all
Plastics▫ 12.1.3.4.4▫ Where the clearance exceeds 10 ft (3.05 m)▫ Base protection on the storage height that would
result in a 10 ft (3.05 m) clearanceOR▫ Provide one level of supplemental, quick-response
in-racks sprinklers located directly below the top tier of storage and every flue space intersection
High Clearance above Storage
• In-Rack Sprinklers
▫ 12.1.3.4.5.1 When applying the supplemental in-rack sprinkler option, the ceiling density shall be based upon the given storage height with an assumed acceptable clearance to ceiling
Back-to-Back Shelf Storage
Back-to-Back Shelf Storage• Design criteria was added to Chapters
14 and 15
Aisle
Max 60”Min 60”For Group A
Max15’
Back-to-Back Shelf Storage
• Back-to-Back Shelf Storage▫ Two solid or perforated shelves up to 30 inches
(762 mm) in depth each▫ Not exceeding a total depth of 60 inches (1.5 m)▫ Separated by a longitudinal vertical barrier such
as plywood, particle board, sheet metal, or equivalent
▫ Maximum ¼-inch diameter penetrations▫ No longitudinal flue space▫ Maximum storage height of 15 feet (4.5 m).
Cartoned Record Storage With Catwalk Access (20.5)
Transverse flue sprinklers
Catwalk sprinklers
Record Storage in Cartons on Racks
• Protection scenario is only permitted for Class III▫ Sprinklers at the ceiling▫ Sprinklers under catwalks▫ Sprinklers in transverse flue spaces
Carton Records Storage
• Carton Records Storage▫ A Class III commodity consisting of predominantly
paper records in cardboard cartons on shelving in a rack storage system.
• Annex ▫ Class III commodity can have up to 5% plastics
▫ Materials stored include Class I and II, paper business records, books, magazines, stationery, newspapers, and cardboard dividers
Carton Records Storage• Structural Criteria▫ Single-row or double-row rack structure with
uprights 10 ft 6 in (3.2 m) apart maximum ▫ Shelving – 50% open▫ Transverse flue spaces; Longitudinal flues not
required▫ Catwalk aisles between racks are open metal
grating that is at least 50% open Catwalk aisles at the ends of racks – solid
▫ Maximum 12 ft (3.7 m) vertical separation for catwalks
Criteria for Carton Records Storage
• Ceiling sprinkler spacing, maximum 100 ft2 (9.3 m2)• Ceiling sprinkler discharge criteria
Up to 25 ft High Over 25 ft High
Ord. Temp
High Temp
Ord. Temp
High Temp
Density 0.33 0.29 0.3 0.4
Area 2000 2000 2000 2000
Hose 500 500 500 500
Duration 2 2 2 2
Sprinkler Criteria
• Catwalk Sprinklers▫ QR, ordinary temp, K-5.6, K-8.0 or K-11.2.▫ In the center +/- 4 inches (102 mm) of each aisle
below each Catwalk level. ▫ Min. 6 inches (152 mm) above the top of storage▫ Supplied from the in-rack sprinkler system.
• Sprinkler spacing within the aisles aligns with the transverse flues and the center of the storage unit when staggered and does not exceed 10 ft 6 in (3.2 m) on center
Compact Storage (Mobile Shelves)(20.6)
Pictures courtesy of Spacesaver
Compact Storage
• Compact Storage▫ Solid shelves▫ 36 inches (914 mm) or less in total depth▫ Arranged as part of a compact storage module▫ 30 inches (762 mm) maximum between shelves
vertically▫ No internal vertical flue spaces other than those
between individual shelving sections.• Compact Storage Module▫ Units move so storage can be pushed together▫ No flues, minimal spaces between units▫ Aisles created by moving the shelving unit
Compact Storage
• Protected w/light hazard sprinkler sys.▫ Limited to 8 ft (2.4 m) in height▫ Only paper files, magazines, books and
similar documents▫ Miscellaneous 5% plastics allowed▫ Must have 18 inches (457 mm) of clearance
above unit to sprinkler deflectors Ordinary temperature, quick-response
sprinklers
High-Bay Record Storage (mobile) (20.7)
High Bay Record Storage
• Ceiling only sprinkler protection ▫ Class III Commodity paper products (files, magazines, books etc)
▫ Corrugated containers either closed or open top, to include corrugated totes, with no more than 5% plastics stored
▫ Mobile (or fixed) shelving units greater than 12 ft (3.7 m) and up to 34 ft (10.4 m) high and up to 30 shelving units (storage tiers) high.
• ESFR Sprinklers▫ K-factor 25.2 at 40 psi (2.8 bar)
High Bay Records Storage
Antifreeze Calculations
• Solutions▫ Weight or volume
• Darcy-Weisbach friction loss for systems over 40 gal in size▫ Finding the friction factor (f)▫ Using the right value of ε for aged pipe
• K-Factor adjustment for sprinklers
Finding “ f ”
• If Reynolds Number (Re) is less than 2000
f = 64/Re
• If Reynolds number is greater than 3000, use Moody Diagram to find “ f ”
• If Reynolds number is between 2000 and 3000, extension of Moody Diagram curves is most conservative solution
Roughness of Pipe
• Measured by the variable “ε” in units of length (inches or feet)
• Divided by diameter of pipe to become dimensionless
• No standardization of how to treat pipes like we have for “C” factor in H-W
Roughness of Pipes
• According to Isman▫ C of 100 = ε of 0.015 inches▫ C of 120 = ε of 0.004 inches▫ C of 150 = ε of 0.000084 inches▫ New steel pipe averages 0.0018 inches▫ These values are in A.22.4.4.5.1 in NFPA 13
• According to Viking▫ C of 120 = ε of 0.00015 ft▫ C of 120 = ε of 0.0018 inches
Roughness of Pipe
0
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0.01
0.011
0.012
0.013
0.014
0.015
0.016
80 100 120 140 160
Hazen-Williams C Factor
Dar
cy W
eisb
ach
E Fa
ctor
Isman
Viking
Adjusting K-Factors for Cold Antifreeze
• Sprinkler has a K-factor of 11.2 with water• Being used in a large antifreeze system with
50% Propylene Glycol by weight• Density is 66.8 lbs/cubic ft (see Figure 7.6.2.5(b)
of NFPA 13 and know that 1g/ml = 62.43 lbs/cu. ft.)
( ) 9.108.66
12.1194.7194.7 ===A
WA KKγ
Antifreeze Example
12345 678910 111213
40 ft of 1¼ inch schedule 40
50 ft of 4 inch schedule 40
2 ft of 2 inch schedule 40
TR1BR1
BR2
BR310’
12’
Antifreeze Example
• Complete calculation using same technique• Final Demand using Darcy-Weisbach▫ Flow = 405 gpm▫ Pressure = 41 psi
• Final Demand using Hazen-Williams▫ Flow = 350 gpm▫ Pressure = 19 psi▫ H-W incorrectly predicted pressure by more than
100% and flow by about 20%