narrative-155 Boston St-signed
NEW RESIDENTIAL SPRINKLER
SYSTEM FOR
THREE-FAMILY BUILDING AT
155 Boston St
Salem, MA
FIRE PROTECTION DESIGN NARRATIVE
Designed By:
Davco Security Systems, Inc.
TABLE OF CONTENTS
SECTION PAGE
TABLE OF CONTENTS ii
INTRODUCTION AND BUILDING DESCRIPTION 1
CODE REVIEW / HAZARD CLASSIFICATION 1
SPRINKLER SYSTEM DESCRIPTION 2-3
HYDRAULIC CALCULATIONS: 3
APPENDIX A 4
– HYDRAULIC CALCULATIONS
– PUMP DATA SHEET
– SPRINKLER CUTSHEET
ii
1
INTRODUCTION AND BUILDING DESCRIPTION
The purpose of this Fire Protection Design Narrative is to describe the proposed
residential wet-pipe automatic sprinkler system to be installed in conjunction with the
renovation of the 3-story building located at 155 Boston St, Salem, MA.
This building has three levels above grade with a full basement. This building is
constructed of combustible materials throughout and meets the criteria of Construction
Type V according to 780 CMR. Sprinkler system will be installed throughout the
building with an aggregate area of around 3100 ft2. The basement will be used as
mechanical space and storage space for the building owner. Any concealed combustible
spaces shall remain inaccessible. Such spaces are not permitted to be used for storage of
any kind.
CODE REVIEW / HAZARD CLASSIFICATION
The Massachusetts State Building Code (780 CMR) classifies this building as Type R-2
construction (Section 310.1).
Section 903.2.8 (780 CMR, 9th Edition) requires buildings of Use Group R to be provided
with an automatic sprinkler system designed and installed in accordance with 780 CMR
903.3.
Exception 1 (Section 903.2.8, 780 CMR) States that Buildings other than R-1
Occupancies and R-2 Dormitories, having no more than three dwelling units shall
be permitted to have an automatic fire suppression system installed in accordance
with 780 CMR 903.3.1.3, provided that every automatic sprinkler system shall
have at least one automatic water supply source in accordance with NFPA 13D
where the minimum quantity of stored water shall equal the water demand rate
times 20 minutes.
Approved by the local authority having jurisdiction, automatic sprinkler systems shall
be installed throughout in accordance with NFPA 13D.
Per these referenced code sections, the sprinkler system for this building has been
designed in accordance with the requirements of NFPA 13D (2013 Edition). The system
shall assume the hydraulically most demanding sprinklers in a single compartment up to
two (2) residential sprinklers operating at the flow and pressures specified by the
manufacturer (defined in the hydraulic calculation section).
2
SPRINKLER SYSTEM DESCRIPTION
The sprinkler contractor shall provide a residential and stored water tank arrangement as
indicated on the associated drawing. The pump shall be set up to operate automatically
upon the detection of water flow via the vane-type flow switch due to a head fusing
because of heat from a fire.
The pump shall be supplied by a stored water supply equaling the maximum flow
requirements of two (2) residential heads operating multiplied at duration of 20 minutes.
A 1 1/4" schedule 40 steel pipe will be running down the length of basement, installed
under the unfinished ceiling. The owner is responsible for providing heat source in the
basement.
Blazemaster CPVC pipe will be used in the finished space. This shall include concealed
risers, branch lines and mains serving the first, second and the third floor, referring to the
enclosed drawing for additional details.
Per NFPA13D-8.3.2 Sprinklers shall not be required in bathrooms of 55 ft2 and less, all
the bathrooms within the individual units are less than 55 ft2, therefore sprinklers are
omitted in these spaces.
Per NFPA 13D-8.3.4, Sprinklers shall not be required in garages, open attached porches,
carports, and similar structures.
Per NFPA13D-8.3.3, sprinklers shall not be required in clothes closets, linen closets,
and pantries that meet all of the following conditions:
(1) The area of the space does not exceed 24 ft2.
(2) The shortest dimension does not exceed 3 ft.
(3) The walls and ceilings are surfaced with noncombustible or limited-combustible
materials as defined in NFPA 220.
For closets within the house meeting the criteria, sprinklers will be omitted.
Per NFPA13D- 8.3.6 Sprinklers shall not be required in covered, unheated projections of
the building at entrances/exits as long as the dwelling unit has another means of egress.
Each dwelling unit is served by two exits, therefore sprinklers are omitted in the foyer in
accordance with NFPA 13D, as described above.
All residential pendent sprinklers shall be GL4910 sprinklers with a K-Factor of 4.9.
These sprinklers require a minimum flow of 14 GPM and a minimum pressure of 8.2
PSI and have an associated maximum spacing limitation of 16’x16’ (No more than 8’ off
any wall).
All residential sidewall sprinklers shall be GL4431 sprinklers with a K-Factor of 4.4.
These sprinklers require a minimum flow of 15 GPM and a minimum pressure of 11.6
PSI and have an associated maximum spacing limitation of 14’x14’ (No more than 7’ off
any wall).
3
NOTE: Per the requirements of the Massachusetts State Fire Marshal, all sprinkler
contractors installing CPVC piping for automatic sprinkler systems shall be certified by
a CPVC representative
HYDRAULIC CALCULATIONS
Per the requirements of NFPA 13D (2013 Edition), the hydraulically most demanding
sprinklers contained within the hydraulically most remote compartment, up to two (2)
sprinklers are required to be included in the hydraulic calculations.
The demand of this hydraulic calculation at the discharge of the pump is 33.2 PSI @
30.0 GPM. According to attached data sheets of GOULDS System 13D pump, GT10
can be used in this building to provide a pressure of 42 PSI at 30.0 GPM.
Based on a demand flow of 30.0 GPM, a minimum stored water supply of 600 Gallons
must be provided. To accommodate the flow demand, two 300 Gallon tanks will be
provided with a total stored water supply of 600 Gallons.
ACCEPTANCE TESTING
This system must be hydrostatically tested at system pressure for 20 minutes.
Additionally, a main drain test and inspectors test will be conducted. Control valve
tamper switch closure tests will also be conducted. A Contractor's Certificate for Above
Ground Piping will be required.
MAINTENANCE TESTING
A testing and maintenance program, which meets the requirements of NFPA Standard 25
shall be required to be under contract with a licensed sprinkler contractor. Test programs
shall be in accordance with Table 5-1 and 12-1 of NFPA 25 and include the following:
Weekly - Owner inspect to see that control valves are open, unobstructed and not
leaking and all system gages are normal.
Yearly - Conduct full Flow Test to verify pump operation and open water supply
from tank(s). Record static, residual and flow readings.
4
APPENDIX A
– HYDRAULIC CALCULATIONS
– PUMP SELECTION CUTSHEET
– SPRINKLER CUT SHEET