ed with the authors of this page or responsible for its content.
Materials used in fire protection systems must be listed for the intended use unless otherwise allowed by the
FIRE PROTECTION SYSTEMS
PIPE MATERIALS

PHOENIX FIRE DEPARTMENT
TECHNICAL MANUAL


M. P. 501.20

PAGE 1 of 25

Pipe is identified by markings
required continuously along
its length. Markings must
include the manufacturer, the
model designation, or
schedule. Pipe listed for fire
protection use must bear the
listing number.
Pipe
Materials
Materials used in fire protection systems must be listed
for the intended use unless otherwise allowed by the
applicable standard. Underground pipe must be listed for
fire protection service.

Ferrous (iron based) pipe may be welded or seamless.
Unlisted pipe used for aboveground installations must
meet the manufacturing standards listed in the tables.

Pipe clamps used for the restraint of plastic pipe can be
unlisted only if the clamp is padded to prevent scoring of
the piping. Sprinkler systems installed in one-and two-
family dwellings typically use plastic pipe concealed in
construction. Exposed pipe in attics must be copper or
steel.


NFPA 13
2-3.1

Pipe used for underground and aboveground fire
protection water supply piping, including risers, mains,
and branchlines must be listed for fire protection use or
meet the standards of NFPA 13 Table 2-3.1.


Underground Pipe
NFPA 24
7-1.1
Piping used for underground water delivery to fire
protection systems must be listed for fire protection
service and comply with AWWA (American Waters
Works Association) standards when connected to the
potable water supply.




Polyvinyl Chloride (PVC) underground pipe is known
as pressure pipe. Plastic municipal water pipe up to 12
inches must meet AWWA C900 specifications (suitable
for potable water). There are three pressure classes for
C900 plastic (PVC) pipe. Class 150 is the minimum
pressure class allowed for fire service.
FIRE PROTECTION SYSTEMS
PIPE MATERIALS

PHOENIX FIRE DEPARTMENT
TECHNICAL MANUAL


M. P. 501.20

PAGE 2 of 25



See NFPA 24 7-1.3. Where underground fire protection
systems are pressurized by a fire pump, AWWA C900,
Class 200 is the minimum acceptable pipe thickness.

A common under ground PVC
pipe used is IPEX Blue
Brute©. It is manufactured in
4, 5, 8, 10 and 12-inch sizes
with couplings and fittings
listed for use with the pipe.
Couplings and fittings are the
same distinctive blue color.
The material is manufactured
by and sold to companies
licensed to produce pipe.


Summer ground temperatures
in central and southern
Arizona can reach 110
degrees F. These high
temperatures reduce the
tensile strength of PVC pipe,
the result of which is pipe
failure.

Although AWWA C-900 PVC water pipe is manufactured
from a PVC compound with a design basis rating of
4,000 psi for water at 73.4 degrees F., ground
temperatures above 75 degrees F. begin to effect the
maximum working pressure negatively.

Pipe is manufactured to cast iron outside diameter size
series for use as a pressure conduit in 4, 6, 8, 10 and 12
inch diameters. Wall thickness classes are designated
by DR numbers and correspond to pressure
classifications: DR-14, Class 200, DR-18, Class 150,
and DR-25, Class 100.
Stresses in the wall of an
underground pipe around the
circumference are called
hoop stresses and are
defined as t
he
circumferential force per
unit areas, psi, in the pipe
wall due to internal
pressure. These stresses
are usually given at 73
degrees F. The design
engineer must calculate
these hoop stresses at the
higher temperatures to
insure pipe integrity in the
summer months.




The following tables show the inside diameters of UL
listed and FM Underground Fire Service Approved PVC
Pressure Pipe. Included are friction loss factors used
instead of calculating the full Hazen-Williams formula,

1.85
1.85
4.87
4.52 Q
P C d
=
, use the factor in its place and multiply
by the flow to the 1.85 power. So,
1.85
4.87
4.52
C
d
results
in an equation reading

1.85
0.0000000622927 Q
P
=

For example, from the AWWA C900 table for Class 150
six-inch pipe, the factor listed is
6.22927E-08
or
0.0000000622927. Assume a flow of 2200 gallons per
minute. The equation would read:

1.85
(0.0000000622927) x (1200 )
P
=

With a friction loss of .0950 psi per foot of pipe. FIRE PROTECTION SYSTEMS
PIPE MATERIALS

PHOENIX FIRE DEPARTMENT
TECHNICAL MANUAL


M. P. 501.20

PAGE 3 of 25


Polyvinyl Chloride Pipe Dimensions (Inches) (C-Factor 150)

Blue Brute® C900 Pressure Pipe Manufactured by J-M MFG CO INC

Class 100 (DR 25) 100 psi Class 150 (DR 18) 150 psi Class 200 (DR14) 200 psi
Nominal
Size
Inside
Diameter
Friction
Loss Factor
Inside
Diameter
Friction Loss
Factor
Inside
Diameter
Friction Loss
Factor
4
4.39
3.16641E-07
4.23
3.79395E-07
4.07
4.57767E-07
6 6.30
5.45232E-08
6.09
6.43107E-08
5.86
7.75726E-08
8 8.28
1.44066E-08
7.98
1.72431E-08
7.68
2.07807E-08
10 10.16
5.3186E-09
9.79
6.37174E-09
9.42
7.68673E-09
12 12.08
2.2893E-09
11.65
2.73126E-09
11.20
3.30886E-09




AWWA C900 Specifications for PVC Pressure Pipe (Inches)


Class 100 (DR 25) 100 psi Class 150 (DR 18) 150 psi Class 200 (DR14) 200 psi

Nominal
Size

Inside
Diameter

Friction
Loss Factor

Inside
Diameter

Friction Loss
Factor

Inside
Diameter

Friction
Loss Factor

4 4.42
3.06311E-07
4.27
3.62398E-07
4.11
4.36476E-07
6 6.35
5.24640E-08
6.13
6.22927E-08
5.91
7.44284E-08
8 8.33
1.39903E-08
8.04
1.66254E-08
7.76
1.9758E-08
10 10.21
5.19295E-09
9.87
6.12414E-09 9.51 7.33889E-09
12 12.14
2.23473E-09
11.73
2.64173E-09 11.31
3.15505E-09








NOTE:
Verify type of joint during field
inspection.

Push-on (bell and spigot) connections of any type of
pipe: NFPA Formal Interpretation.
Gasketed push-on and mechanical joints without special
locking devices have limited ability to resist separation
due to movement of the pipe. Therefore, all tees, plugs,
caps, bends, and hydrant branches having such joints
shall be restrained against movement. For the case of
welded joints and approved special restrained joints,
such as provided by approved mechanical joint retainer
glands, locked mechanical and push-on joints, or locking
threaded rings, no additional restraint against movement
is required
.
(No thrust blocks).
FIRE PROTECTION SYSTEMS
PIPE MATERIALS

PHOENIX FIRE DEPARTMENT
TECHNICAL MANUAL


M. P. 501.20

PAGE 4 of 25


Illustration of bell and spigot assembly

Joining method for common underground pipe
including PVC and cast iron.

(Details of pipe joint may differ from material to material.)

Plastic pipe expands and
contracts with temperature
changes more than any other
type of pipe material. For this
reason, gaskets are installed
between the pipe sections.
Gaskets must be clean and
free of debris. The gasket is
lubricated as pipe lengths are
joined.

Gasketed joints are a major
source of leakage. Pipe
failure is rare.
NFPA 24
8-9.3.1
AWWA C111

Under AWWA C900, PVC municipal water pipe is tested
in the factory at four times its design pressure for five
seconds. Field-testing after installation requires a 200-
pound test for two hours.

The 200 pound pressure test applicable to the
installation of this type of pipe helps seal the gasket.
Piping will leak if the sealing surface is not clean, the
gasket was not properly lubricated, or if the pipe lengths
arent assembled properly. Once the pipe is properly
joined, it can flex at the joint without leakage.
Manufacturers limit the flexion to 1.5-2.0 degrees.
Manufacturers data must be used to determine the
maximum deflection for a particular type or model of
pipe.

Ductile iron pipe is classified
by thickness; Classes 50, 51,
52, 53, 54, 55, and 56, or by
pressure, Standard Pressure
Class 150, 200, 250, 300, or
350. Higher pressures are
available as high-pressure
pipe.

AWWA C104







NFPA 24, 7-2


Ductile Iron Pipe
Ductile iron pipe has superior strength, toughness,
impact resistance, and corrosion resistance. For these
reasons it is used underground under vehicular traffic,
through foundations and under building footprints. The
interior of ductile iron pipe used for water service has a
cement-mortar lining that is centrifugally applied. NFPA FIRE PROTECTION SYSTEMS
PIPE MATERIALS

PHOENIX FIRE DEPARTMENT
TECHNICAL MANUAL


M. P. 501.20

PAGE 5 of 25










AWWA C105
24, 7-2, requires this coating. The pipe is spun and a
predetermined amount of cement-mortar slurry is fed
into the turning pipe to evenly coat the interior surface.
This provides a high degree of interior smoothness and
can maintain a C-factor of 140 for many years.

The exterior of ductile iron pipe is protected from
corrosion by a polyurethane coating. The integrity of this
coating must be maintained and joints and fittings
protected by field coating and wrapping after assembly.


NFPA 24, 8-3.5
Ferrous pipe used for underground water supplies