Introduction to
Water Pipe Sizing
Understanding the Many
Methods to Size Water Pipe
ONTARIO PLUMBING
INSPECTORS ASSOCIATION INC.
In the public service since 1920
Presented by:
Rainier Bratsch-Blundel, CPSI
Introduction to
Water Pipe Sizing
Where to start.
ASPE Data Books
2006 Building Code
Introduction to
Water Pipe Sizing
What is found in the ASPE Data Books?
1. A list of empirical formulae for piping friction
losses including;
The Hazen-Williams Formula
city mains and fire mains
The Darcy-Weisbach Formula
plumbing and process piping – friction factor is determine by the Colebrook equation
Introduction to
Water Pipe Sizing
What is found in the ASPE Data Books?
2. A method formula for probability of use.
Uses a series of tables assigning Water Size Fixture Units to the most common found fixtures in a
plumbing system.
This is the method found in the Body of the Codes and Appendices of the National Plumbing Code of Canada and Ontario Plumbing Code and Guide.
Introduction to
Water Pipe Sizing
Where to look in the Building Code?
7.6.1.1. Design, Fabrication and Installation
(1) Potable water systems shall be designed, fabricated and
installed in accordance with good engineering practice, such as that described in the ASHRAE Guide and Data Books, the ASHRAE Handbooks and ASPE Data Books.
(ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers, last update 1972),
(ASPE: American Society of Plumbing Engineers, updated 2005)
Introduction to
Water Pipe Sizing
More from the Building Code?
7.6.3.1. Design
(1) Except as permitted in Sentences (2) and (3), the size of
every pipe in a water distribution system that supplies water to a fixture or device and the flow pressures at the supply openings shall be designed to provide peak demand flow in conformance to Table 7.6.3.1.
(2) A tail piece or connector not more than 750 mm long and
not less than ¼ in. inside diameter may be used to supply water to a fixture or device.
Introduction to
Water Pipe Sizing
More from the Building Code?
7.6.3.1. Design (cont.)
(3) A water distribution system that serves not more than a
single dwelling unit does not need to conform to Column 3 of Table 7.6.3.1.
(4) No water system between the point of connection with the water service pipe or the water meter and the first branch that
supplies a water heater, shall be less than ¾ in. size.
(5) Every pipe that supplies a fixture shall have a capacity that
will produce a flow in the fixture that will flush the fixture and keep it in a sanitary condition.
Introduction to
Water Pipe Sizing
Where to look in the Building Code?
7.6.3.2. Hydraulic Load
(1) Except as provided in Sentence (3), the hydraulic load of a fixture or device that is listed in Table 7.6.3.1. shall be the
number of fixture units given in the Table.
(3) Where fixtures are supplied with both hot and cold water,
the hydraulic loads for maximum separate demands shall be 75% of the hydraulic load of the fixture units given in Tables 7.6.3.1. and 7.6.3.2. when using a detailed engineering
Introduction to
Water Pipe Sizing
T-7.6.3.1.
T-7.6.3.2.
Introduction to
Water Pipe Sizing
What's in the Appendix of the Building Code?
The following may be used as an alternative in determining the size of each section of the water system. This is based on proven design methods found in the Appendix of the National Plumbing Code of Canada.
To determine the size of each section of the water supply and distribution systems, use Table A-7.6.1.1.(1), which
incorporates the requirements of Sentence 7.6.2.3.(3) for sizing the Water Service Entering the Building.
Introduction to
Water Pipe Sizing
STEP 1: Determining conditions
On a proposed water piping installation sized pursuant to Table A-7.6.1.1.(1), the following conditions need to be determined:
i. the total number of "Water Supply Fixture Units" as determined from Tables 7.6.3.1. and 7.6.3.2. for the fixtures to be installed,
ii. the developed length of the pipe from the property line to the most remote outlet, or if the pressure at the property line or meter is unknown, the developed length from the public water main to the most remote outlet,
Introduction to
Water Pipe Sizing
STEP 1: Determining conditions
On a proposed water piping installation sized pursuant to Table A-7.6.1.1.(1), the following conditions need to be determined:
i. the total number of "Water Supply Fixture Units" as determined from Tables 7.6.3.1. and 7.6.3.2. for the fixtures to be installed,
ii. the developed length of the pipe from the property line to the most remote outlet, or if the pressure at the property line or meter is unknown, the developed length from the public water main to the most remote outlet,
Introduction to
Water Pipe Sizing
STEP 1: Determining conditions (cont.)
iii. the difference in elevation between the water
piping at the property line or other source of
supply and the highest fixture or outlet,
iv. the pressure in the public water main or other
source of supply at the locality where the
installation is to be made (this pressure may
need to be reduced so that the pressure in the
water distribution system does not exceed 550
kPa); and,
Introduction to
Water Pipe Sizing
STEP 1: Determining conditions (cont.)
v. finally, in localities where there is a wide
fluctuation of pressure in the main throughout
the day, determine the minimum pressure
available, which will be used as a basis for this
design.
Introduction to
Water Pipe Sizing
STEP 2: Water Service Pipe
i.
Beginning with the available pressure at the
property line, public water main or other souce
of supply, and subtracting 10 kPa for each
metre of difference in elevation between such
source of supply and the highest water outlet in
the building or on the premises, use the
"Pressure Range" group in Table A-7.2.6.1.(1)
within which the adjusted pressure falls.
Introduction to
Water Pipe Sizing
STEP 2: Water Service Pipe
ii. Select the "Length Column" that is equal to or
longer than the required length of service pipe.
Follow down the column to a "Water Supply
Fixture Unit" equal to or greater than the total
number of units required by the installation.
Having located the
proper unit value for the
required length, locate the size of the water
Introduction to
Water Pipe Sizing
Introduction to
Water Pipe Sizing
Introduction to
Water Pipe Sizing
Introduction to
Water Pipe Sizing
STEP 3: Cold Water Piping
Starting at the most remote outlet on the cold water piping and working back toward the water service or meter, using the total developed length of pipe, calculate the pipe size for the system using the total "Water Supply Fixture Unit" values given in Tables 7.6.3.1 and 7.6.3.2. and adding the unit demand of the hot water inlet at the point where it
occurs. The final size of the cold water service need not be larger than the size required by Table A-2.6.1.1.(1) for the water service.
Introduction to
Water Pipe Sizing
STEP 4: Hot Water Piping
Starting at the most remote outlet on the hot water piping and working back toward the service water heater,
calculate the pipe sizing for the system from the "Length Column" selected in Table A-7.6.1.1.(1) using the "Water Supply Fixture Unit" valves given in Table 7.6.3.1. and 7.6.3.2.
Introduction to
Water Pipe Sizing
Example OBC:
Bath Lav WC Hose KS DW Cl. W. HWT Bath Cl. W. WC Lav Bath Lav WC SHR Lav WC KS DW Hose BibbIntroduction to
Water Pipe Sizing
T-7.6.3.1.
T-7.6.3.2.
Introduction to
Water Pipe Sizing
(i) the total number of "Water Supply Fixture Units"
FIXTURE 7.6.3.1. 75% W.S.F.U FIXTURESW.S.F.U. COLD HOT W.C. 3 NA 3 4 12 -LAV 1 .75 .75 4 3 3 BATH 2 .75 1.5 3 4.5 4.5 SHR 2 .75 1.5 1 1.5 1.5 K.S. 2 .75 1.5 2 3 3 D.W. 3 NA 3 2 - 6 CL.W. 3 .75 2.25 2 4.5 4.5 H.B. 4 NA 4 2 8
-Introduction to
Water Pipe Sizing
(ii) – (iv) Determining Conditions
(ii) - (iv) DETERMINE CONDITIONS
DEVELOPED LENGTH 23 m PRESSURE AT SOURCE 550 kPa CHANGE IN ELEVATION 9 m MINUS 10kPa PER metre - 90 kPa PRESSURE RANGE 460 kPa
Introduction to
Water Pipe Sizing
Introduction to
Water Pipe Sizing
STEP 2: Water Service Pipe
SIZING as per A-7.6.1.1.(1)
WATER SERVICE 1” (1 1/4“) WATER DISTRIBUTION PIPING 1” 55 WSFU 3/4” 24 WSFU 1/2" 7 WSFU 1 1/4” 108 WSFU
Introduction to
Water Pipe Sizing
Example OBC:
STEP 3: Cold
Water Piping
Bath Lav WC Hose KS DW Cl. W. HWT Bath Cl. W. WC Lav Bath Lav WC SHR Lav WC KS DW Hose Bibb 1/2" 1/2" 3/4" 1/2" 3/4" 1/2" 3/4" 3/4" 1/2“ 3/4" 1" 1 1/4" 1 1/4" 3/4" 1/2" 1/2" 1/2“ 1/2" 1" 1 1/4“Introduction to
Water Pipe Sizing
Example OBC:
STEP 4: Hot
Water Piping
Bath Lav WC Hose Bibb KS DW Cl. W. HWT Bath Cl. W WC Lav Bath Lav WC SHR Lav WC KS DW Hose Bibb 1/2" 1/2" 3/4" 1/2" 3/4" 1/2" 3/4" 3/4" 3/4" 3/4" 1/2" 1/2" 3/4"Introduction to
Water Pipe Sizing
Changes to the National Plumbing Code (NPC);
2.6.3.1. Design
(1) Every water distribution system shall be designed
to provide peak demand flow when the flow
pressures at the supply openings conform to
Table
2.6.3.1.
the plumbing supply fitting manufacturer’s
specifications.
Introduction to
Water Pipe Sizing
Changes to the National Plumbing Code;
2.6.3.4. Size
(5) Where both hot and cold water is supplied to fixtures in residential
buildings containing one or two dwelling units or row houses with separate water service pipes, the water system may be sized in accordance with Table 2.6.3.4. where:
(a) the hydraulic loads for maximum separate demands on water
distribution system piping are not less than 100% of the hydraulic
load of the fixture units given in Table 2.6.3.1. or 2.6.3.2. for private
use,
(b) the minimum water pressure at the entry to the building is 200 kPa,
and
Introduction to
Water Pipe Sizing
Addition of Table 2.6.3.1.
to the NPC;
Introduction to
Water Pipe Sizing
Table 2.6.3.4.
Water Pipe Sizing for Buildings Containing One or Two Dwelling Units or Row Houses with Separate Water Service Pipes
Forming Part of Sentence 2.6.3.4.(5)
Note to Table 2.6.3.4.:
(1) Table 2.6.3.4. is not intended to limit water velocities that are specified in Sentence 2.6.3.5.(1)-2010. Size of Water Pipe, inches Water Velocity, m/s(1) 3.0 2.4 1.5
Hydraulic Load, fixture units
½ 8 7 4
¾ 21 16 9
1 43 31 18
Introduction to
Water Pipe Sizing
Changes to the National Plumbing Code;
2.6.3.5. Velocity
(1) The maximum permitted flow velocities shall be
those recommended by the pipe and fitting
Introduction to
Water Pipe Sizing
Example NPC:
Bath Lav WC Hose Bibb KS DW Cl. W. HWT Bath Cl. W. WC Lav Bath Lav WC SHR Lav WC KS DW Hose BibbIntroduction to
Water Pipe Sizing
(i) the total number of "Water Supply Fixture Units"
FIXTURE 7.6.3.1. H/C TOTAL FIXTURES W.S.F.U. COLD HOT W.C. 2.2 4 8.8 8.8 -LAV 0.5 4 2.8 2 2 BATH 1 3 4.2 3 3 SHR 1 1 1.4 1 1 K.S. 1 2 2.8 2 2 D.W. 1.4 2 2.8 - 2.8 CL.W. 1 2 2.8 2 2 H.B. 2.5 2 5 5 -H/C 2.2 0.7 1.4 1.4 1.4 1.4 1.4 2.5
Introduction to
Water Pipe Sizing
Example NPC:
Cold Water
Piping
Bath Lav WC Hose Bibb KS DW Cl. W. HWT Bath Cl. W. WC Lav Bath Lav WC SHR Lav WC KS DW Hose Bibb 1/2" 1/2" 3/4" 1/2" 1/2“ 3/4" 3/4" 1 " 1" 3/4" 1/2" 1/2“ 1/2" 1" 1“Introduction to
Water Pipe Sizing
Example NPC:
Hot Water
Piping
Bath Lav WC Hose KS DW Cl. W. HWT Bath Cl. W WC Lav Bath Lav WC SHR Lav WC KS DW Hose Bibb 1/2" 1/2" 1/2" 1/2" 3/4" 1/2" 3/4" 3/4" 1/2" 1/2" 3/4"Introduction to
Water Pipe Sizing
QUESTIONS?
www.opia.info/members/ http://www.georgebrown.ca/apprenticeship/ seminar_backflow.aspx [email protected] http://nationalcodes.ca/eng/public_review/2008/ proposed_changes.shtmlIntroduction to
Water Pipe Sizing
Understanding the Many
Methods to Size Water Pipe
ONTARIO PLUMBING
INSPECTORS ASSOCIATION INC.
In the public service since 1920
Presented by:
Rainier Bratsch-Blundel, CPSI