tn marapr 2007

8/10/2019 TN MarApr 2007

1/4

Sprinkler

Volume XXX No. 2 March/April 2007 Kenneth E. Isman, P.E., Editor

Significant Changes to NFPA 24

The 2007 Edition of NFPA 24 has been published by the NFPA and is available forpurchase. The following is a compilation of important changes that were made to the

standard. This list is not intended to be all inclusive, but is meant to pick up the

highlights of issues that the editor thinks are most important.

Working Plans (4.1.3) A new section covers 10 items that have to be provided to the

AHJ as a part of the working plan submittal:

Name of owner Location, including street address

Point of compass

A graphic representation of the scale used on all plans

Name and address of contractor

Size and location of water supplies

Size and location of standpipe risers, hose outlets, hand hose, monitor nozzles,and related equipment

The following items as they pertain to the private fire service main:- Size, length, location, weight and material of pipe

- Point of connection to city main- Sizes, types, and locations of valves, valve indicators, regulators, meters and

valve pits

- Depth at which the top of the pipe is laid below grade

- Method of restraint

The following items as they pertain to hydrants:

- Size and location, including size and number of outlets and whether outletsare equipped with independent gate valves

- Whether hose houses and equipment are provided and by whom

- Static and residual hydrants used in flow tests- Method of restrain

Size, location and piping arrangements for FDCs

Installation Instructions (4.1.4)The working plans are also required to include themanufacturers installation instructions for any specially listed equipment including

descriptions, applications and limitations.

Published bimonthly by the National Fire Sprinkler Association, Inc. for its members.40 Jon Barrett Road Patterson, NY 12563 U.S.A. (845) 878-4200 FAX (845) 878-4215

Information contained in this newsletter is derived from sources believed to be reliable. NFSA cannot guaranteeaccuracy of all information. Statements and conclusions are based on the best judgment of the NFSA Engineering Staff.

2007 NFSA, Inc. Cannot be reproduced without permission of the editor.

TechNotes

8/10/2019 TN MarApr 2007

2/4

Sprinkler TechNotes March/April 2007 Page 2

Signage (5.9.5.4) Where the system demand pressure exceeds 150 psi, a sign isrequired on the FDC that contains the demand pressure.

Post Indicator Valves (6.3) Unless the requirements in the next sentence are met,every connection from a private main into a building needs a PIV. A PIV can be

eliminated if the AHJ allows it and if a valve is installed to isolate the fire protectionsystem from the private main.

Grounding and Bonding(10.6.8) In no case can the underground piping be used as

the grounding electrode. Bonding for lighting protection in accordance with NFPA 780

is okay. Bonding together multiple grounding mechanisms that include the undergroundfire protection piping is okay and required by the NEC (NFPA 70).

Inspections Prior to Installation (10.7.1) All pipes, valves, hydrants and fittings willbe required to be inspected when they are received and again prior to installation.

Installation contractors will be asked to state that they have done this on the acceptance

test form.

Restrained Joint Systems (10.8.3) A new section was added to clarify that restrained

joints includes one or more of the following:

Locking mechanical or push-on joints

Mechanical joints utilizing setscrews retainer glands

Bolt Flange joints

Heat-fused or welded joints

Pipe clamps and tie rods

Other approved methods or devices

Hydrostatic Test Pressure (10.10.2.2) The standard was clarified regarding thepressure to use during the hydrostatic test. The base requirements of a test pressure of

200 psi or 50 psi over the maximum system working pressure are pretty standard. But

the new rule is a tolerance during the test of 5 psi for 2 hrs. The committee alsoclarified that the pressure is to be recorded at a hydrant or the lowest point in the systemwhere no hydrant is provided.

Hydrostatic Test (10.10.2.2) The committee also clarified the following four items with

respect to the performance of the hydrostatic test:

A test of the fire department connection piping is also required

Thrust blocks need to be hardened before testing

Backfill between joints is permitted to prevent movement of the piping, butcovering joints is discouraged so that leaks can be observed

An annex section recommends pre-stabilizing the system and an intermediatecheck of the system 1-hour into the test for leakage

8/10/2019 TN MarApr 2007

3/4


Leakage (10.10.2.2.4) The old leakage test has been replaced with a HydrostaticTesting Allowance. The allowance will be based on the following formula:

000,148

PSDL =

L = makeup water (gallons per hour)S = length (feet)

D = diameter (inches)

P = average test pressure (psi)

Additional Hydrostatic Test Methods (10.10.2.3) NFPA 24 will also recognize the

Hydrostatic Test procedures from the following American Water Works Association

documents. However, it does not appear from the way that this new section is wordedthat these procedures replace the requirements discussed previously. It only appears that

these tests are permitted to be done in addition to the other requirements of NFPA 24.

The other documents that are referenced are:

AWWA C600,Installation of Ductile Iron Water Mains and Their

Appurtenances, 1999

AWWA C602, Cement-Mortar Lining of Water Pipe Lines 4 inch and Larger inPlace, 1999

AWWA C603, Standard for the Installation of Asbestos-Cement Water Pipe,

1990

AWWA C900, Polyvinyl Chloride (PVC) Pressure Pipe, 4 inch through 12 inch,

for Water and Other Liquids, 1989

Operational Tests of Valves and Hydrants (10.10.2.4) The following tests wereadded to be performed at the system acceptance:

Hydrants are to be fully opened and closed under system pressure

Dry-barrel hydrants are to be checked for drainage

All valves are to be fully closed and opened under pressure

Where fire pumps are installed, run all of the above tests are to be run with thefire pump running

Acceptance Test of Backflow Preventers (10.10.2.5) Language was added to requirethe forward flow testing of backflow prevention devices. The minimum flow during the

test is required to by the maximum fire protection system demand downstream of the

backflow preventer, including inside and outside hose stream demands if these demandsare applicable (hydrants or hose connections are downstream of the backflow preventer).

Contractors Certificate(10.10.1) Updated as required to contain new items asdiscussed above.

8/10/2019 TN MarApr 2007

4/4


Inside Diameter of Pipe (A.10.1.6) A new Table A.10.1.6 has been added to the

standard with the actual inside diameter for different classes of lined ductile iron pipe.

The new table has been necessary because people have been forgetting to subtract the

lining thickness when performing hydraulic calculations. Most people have been gettingthe pipe criteria from the manufacturer and using the inside diameter of the unlined pipe,

forgetting about the lining thickness. This new table is only good for manufacturers that

use standard thickness linings. Some manufacturers use double thickness linings, so theactual inside diameter of their pipe will be even less than what is in the standard.

Flow Testing and Hydrant Marking (Annex) NFPA 291 used to be a recommended

practice that outlined the procedures to use in conducting flow tests of private fire service

mains (water supplies) and also recommended methods of painting fire hydrants differentcolors in order to tell how much flow was available from the hydrants. Several years ago,

the NFPA contemplated eliminating this recommended practice because few proposalsever came in to revise the documents, so the NFPA thought that they were not being

used. When the NFPA floated the idea out to the public to eliminate the recommendedpractice, they got a lot of feedback that it would not be a good idea. So, the

recommended practice was given to the NFPA 24 committee, which decided that it wouldbe good to continue printing this material in NFPA 24 as annex material. Two new

annexes have been added to the standard:

Annex CRecommended Practice for Fire Flow Testing

Annex DRecommended Practice for Marking of Hydrants

tn marapr 2007

Documents