Natural Gas Pipe Sizing Section

8/11/2019 Natural Gas Pipe Sizing Section

1/12

E.I

Piping

design sizing imperial

ote This informative

Annex

has

been

written in

normative

language to

facilitate adoption where users of

the

Code or

regulatory

authorities

wish

to

adopt it formally as additional

requirements

to this

Code

E.I.4

Multipliers to be used when the relative density of the gas is

other than 0.60

shall be as given

in

Table

A.15.

Canadian Standards Association

749 7 70

E.I.I

The required minimum size of Schedule

40

iron pipe shall

be determined

for

each

section

and each

outlet

of

th e

piping system shown

in

Figure E.1 . The

gas

has a relative density of 0.60

and

a heating value of

1000 Btu/ft

3

in the example shown in Figure E.1 .

In the example, the gas pressure in the section X A

is

2 psig, and the gas pressure from A

to

all ppli n es

is less

than

14 in

W e

Annex E informative

Example ofpiping design sizing imperial

and

metric

E.I.2

The pipe size for the sections from A

to

all ppli n e outlets shall be determined.

The distance between the last stage regul torA and the farthest ppli n e Eshall be established in

th e example shown in Figure E.1, it is 50 ft) to

determine the

longest run of th e system operating under

th e pressure of 14 in

W e

This distance shall t hen be used to size the entire system downstream of the

regul tor A. The choice of tables for a specific application shall be determined by the pressure supplied to

th e system

and

the pressure

drop

allowed.

Using the

50

ft line of Table A.2 imperial), the pipe sizes shall

be

as follows:

a) D-E for

60 000

Btuh requires an

NPS 1/2;

b) D-F for

25 000

Btuh requires an

NPS 1/2;

c)

C-G

for

150 000

Btuh requires an

NPS 3/4;

d)

B H

for

40000

Btuh requires an

NPS 1/2;

e)

C-D

for

85 000

Btuh requires an

NPS

1/2;

f) B-C for 235 000 Btuh requires an NPS 1; and

g) A-B for 275

000

Btuh requires an NPS 1.

E.I.3

The pipe size for t he 90 ft section X A operating at 2 psig using Table A.3 imperial) for 275 000 Btuh shall

be determined.

An

NPS 1/2 pipe shall

be

required.

236

January

2 70


2/12

Service regulator and

meter

t

System regulator

Note: The example shown is of a general nature and does not

necessarily

include the allowances that

shall be

taken into

account in each particular installation

In every

installation all pertinent requirements in Clause 6 shall be adhered to

9

ft 20 ft 10ft C 10ft

~ 7 7 / r 4 4 ~ 4

D

B

V1


System operating at 2

psig

X

Natural

gas

andpropane

installation code

System operating at less than 1/2

psig

40000

Btuh

H

60000

Btuh

E

.t: F

V1

25000 Btuh

G

150000 Btuh

Figure E.I

Example

of

pipe design. sizing imperial

See Clauses E.1.1

an d

E.1.2.

E 2

Piping

design

sizing

metric

E 2

The required minimum size of Schedule 40 iron pipe shall be determined for each outlet of th e piping

system

shown

in Figure E 2 The gas has a relative density of

0.60

and a heating value of 38 MJ/m

3

in

the

example shown

in Figure E 2

In th e example, th e gas pressure in th e section X A is 14 kPa, and th e gas pressure from A

to

all

ppli nces is less than 3.5

kPa

E 2 2

The pipe size for th e sections from A to

all

ppli nce outlets shall be determined.

The distance

between

the last

stage regul tor

A

and

the farthest

ppl nce

Eshall be established

in the example, it is 15 m to determine th e longest run of th e system operating under th e pressure of

3.5

kPa

This distance shall

then

be used to size the entire system downstream of the regul tor

A

The

choice of tables for a specific application shall

be determined

by

th e

pressure supplied

to

the system

and

th e pressure

drop

allowed.

Using the 15m line of Table A.2 metric , the pipe sizes shall be as follows:

a D-E for

17.5

kW requires

an

NPS

1/2;

b D-F for 7.0

kW

requires an NPS 1/2;

c C-G for 45.0 kW requires an NPS 3/4;

January

1

37


3/12

E.2.4

Multipliers to be used when the relative density of the gas is other than

0.60

shall be as given in

Table A.15.

E.2.3

The pipe size for

the 27

m section X A operating

at

14

kPa

using Table A.3 metric) for

81.5

kW shall

be

determined.

An

NPS

1/2 pipe shall

be

required.

Service regulator

andmeter

t System regulator

Note: The example shown is of a general nature and does not necessarily include the allowances that shall be taken into

account in each

particular

installation every

installation

all pertinent requirements

in Clause

6 shall be adhered

to

17.5 kW

E


E

12 kW

H

System operating at less than 3.5

kPa

Figure

E

Example of pipe design sizing metric

See Clause E.2.1.)

System operating at 14 kPa

E

7 m

6m

3m

C

3m

B

E

:

E

F

:

f

7.0kW

G

45

kW

8749 7 70

d)

B H

for

12.0

kW requires an

NP

1/2;

e)

C D

for 24.5

kW

requires an NP 1/2;

f) B-C for 69.5 kW requires an

NPS

1; and

g) A B for 81.5 kW requires an NPS 1.

8

January 20 70


4/12

G 1

ote

This Annex is not a mandatory part of this Code,

nnex

F informative

uggested

gener l dimensions

for

dr ft hoods


Natural

gas and propane installation code

D

I

A ~ I

~

K

january 7

A

1 1

I ~

igure

l

Suggested general dimensions for a vertical draft hood

Continued

9


5/12

N

l;J)

-

.I>.

0

Dimensions, in

mm )

:

-

-

C

D E F G H I

J

K L M

0

3 75

5.5 140 7.0 178 3.8 97 0.7 18 4.4 112 3.0 76

1.5 38 2.5 64

0.7

18

1.5 38 2.3 58

4 100

7.2 183 9.5 241 5.0 127

1.0

25 6.0 152

4.0

102 2.0 51)

3.5 89

1.0

25

2.0

51 3.0 76

5 125

9.4 240 10.8 274 5.3 135 1.5 38 8.0 203 5.0 127 2.3 58 4.0 102 0.9 23

2.4 61 3.5 89

6 150

11.5 292 12.0 305 5.6 142 1.9 48) 9.8 249 6.0 152 2.5 64 4.5 114 0.8 20

2.7

69 4.0 102

7 175 13.5 343

13.9 353

6.4 163 2.3 58 11.6 295 7.0 178 2.9 74 5.3 135

0.9

23

3.1

79 4.6

117

8 200 15.5 394 15.8 401

7.1

180

2.7

69 13.4 340 8.0 203 3.2 81 6.0 152

1.0

25 3.5 89 5.3 135

9 225 17.4 444 17.5 444 7.7 196 3.1 79

15.2 386 9.0 229 3.5 89 6.7 170 1.0 25

4.0

102 5.8 147

10 250) 19.7

500 18.8 478

7.9 201

3.6 91

17.2 437 10.0 254 3.8 96 7.3 185

1.0

25

4.3

109 6.2 157

11

275 22.2

564 20.7 526

8.4 213

4.3

109 19.6 498 11.0 279 4.1 104 8.0 203 1.5 38

4.6 117 6.6 168

12

300 24.7 627 22.2 564 8.7 221 5.0 127

22.0

559 12.0 305

4.4

112 8.5 216

1.7

43 5.0 127 7.0 178

ote Figure 1 illustrates only one design of a vertical draft hood and is not to be construed as the only design that maybe used hood of any other design

that

meets the requirements

of CS CANl 6 2 is

acceptable

Figure

F. l

Concluded

I::

N

o

-

@

b

::J

Q

::J

Q

::J

2-

i

o

g

::J


6/12

Natural

gas and propane installation

code

I

I I I

1--

C

to I

I

F / l ~ /

1

M

I

r

j

i

H

t------ot

1---------1

A

- - - - - - ~ ? ~ - - - - r :

; 1

-

J-----

E

:r--j----;

Baffle

strap

Relief opening

Dimensions,

i n m m)

A

C D

E F G H

3 75) 6 150)

1-1/ 2 38)

4-3/4 121)

3-3/4

95) 1-3/8 35)

2-1/2 64)

4 100) 8 200)

2 50) 4-3/4 121) 5 125) 1-7/8 48)

3-3/8 86)

5 125) 10 250)

2-1/2 64) 4-3/4 121)

6-1/4 159)

2-3/8 60)

4-3 /1 6 106)

6 150) 12 300) 3 75)

4-3/4 121) 7-1/ 2 190) 2-7/8 73) 5 125)

7 175)

14 350) 3-1/ 2 89) 4-3/4 121) 8-3/4 222) 3-3/8 86) 5-7/8 149)

8 200) 16 400) 4 100)

4-3/4 121)

10 250)

3-7/8 98)

6- /16 1 70)

9 225) 18 450)

4-1/2 1 14)

4-3/4 121) 11-

1/ 4

286) 4-3/8 111)

7 1/ 2 190)

10 250) 20 500) 5 125) 4-3/4 121)

12 -

1/ 2 318) 4-7/8 124)

8-3/8 213)

275)

22 550)

5-1/2 140)

4-3/4 121) 13-3/4 349)

5-3/8

136)

9-3/16 233)

12 300) 24 600) 6 150) 4-3/4 121)

15 381)

5-7/8 149) 10 250)

J

K

L M

2-1/ 2 64) 2-1/2 64) 2-1/ 8 54) 9/16 14)

1-3/4 44)

3-3/8 86) 3-3/8 86)

2-7/8

73) 3/ 4 19)

2-5/16 59)

4-3/16 106) 4-3/16 106) 3-1/ 2 89) 15/16 24)

2-15/16 75)

5 125) 5 125) 4-1/4 108) 1-1/ 8 29)

3-

1/ 2

89)

5-7/8 149) 5-7/8 149) 5 125) 1-5/16 33)

4-1/16 102)

6-11/16

1 70)

6-11/1 6 1 70) 5-5/8 143) 1-

1/ 2

38)

4- /1 6 9)

7-1/2 190) 7-1/2 190)

6-3/8

162)

1-11/16 43) 5-1/ 4 133)

8-3/8 213)

8-3/8

213)

7 175)

1-7/8

48) 5-1 3/16 148)

9-3/16 233) 9-3/16 233)

7-3/4

197) 2-1/16 57)

6-3/8 162)

10 250) 10 250)

8-1/ 2 216)

2-1/4 57)

7 175)

Canadian Standards ssociation

Note:

Figure

F

illustrates only one design

of

a horizontal

draft hood

and

is

not

to

be

construed as the only design

that

may be

used

A

hood

of

any other design that meets the requirements

of

CSA CANl 6 2 is acceptable

igure F

uggested

general dimensions for

a

horizontal draft hood

January 2010

4


7/12


8/12

Note: This informative nnex

has been written in

normative language

to facilitate adoption

where users of

the

Code

or

regulatory authorities wish to adopt it formally as additional requirements to

this

Code

Canadian

Standards

ssociation

Annex informative

iping

exp nsion nd

flexibility

Natural gas

and propane

installation code

G I General

Problems are

not

usually experienced

in

residential piping systems with thermal expansion because

th e piping is relatively short.

owever in commerci l and industri l buildings there can be substantial variations in th e lengths of

gas piping mains as

the

indoor temperature changes

on

weekends

or

between seasons.

It

is therefore

essential

that

provisions be made in the piping design for flexibility to avoid undesirable bending

and

strong forces

at

elbows

or

joints.

This flexibility is obtained by

the

use of designed pipe bends, loops, offsets, expansion, hints, or swivel

joints.

The

piping shall

be

anchored

at appropriate

locations

to

control

the

direction of expansion

and

contraction.

G

Gas piping

to rooftop units

Due to

the

wide range of

temperatures on

a roof between

summer

and winter, piping design shall provide

for expansion and contraction. Because of

the

exposure

to

sunlight and rain or snow, coated or wrapped

gas piping is

not recommended

Bare steel piping

and fittings

shall

be

cleaned after assembly,

painted

with a metal primer, and given at least one coat of exterior enamel paint.

Expansion control loops should be used

on

pipe sizes of 2

in

50 mm

or

less

whenever the

unrestrained

pipe length is

at

least 100 ft 30 m . Larger diameter piping is generally installed with expansion joints.

As shown in

Figure G.1,

the

control loop consists of 90 offsets to

th e

main pipe run so it provides

an

open ended box configuration.

For purposes of design, a 90

change

of direction or an offset may be considered the equivalent to a

control loop when

the

offset length is

at

least three times Dimension A in Figure G.1.

Some

form of thermal expansion control shall

be

provided for each

100

ft 30 m . For example, a

200

ft

61

m length shall be anchored

in the

centre between each loop. The anchor of an offset

or

90

bend

should be

not

closer than 10ft 3 m from

the bend to

permit expansion.

Suitable pipe supports are commercially available to permit th e free movement of piping when it

expands and contracts.

January 20 70 43


9/12

8749 7 70

44

Wall thickness

Schedule

40 ,

I ron pipe size, in in mm

3/4 0.11 3 2.87

1 0.133 3.38

1-1/4 0.140

3.56

2

1.154

29.31

Figure G l

Expansion

control loop

See Clause G.2.

anadian

Standards

ssociation

Dimension

ft

m)

4.5 1.4

5.0 1.5

5.5 1.6

6.5 2.0

January 2070


10/12

Annex H normative

urging ofpiping nd

tubing

systems where

re dily ccessible

burner

is

not v il ble or

where n ppli nce

is

not

equipped

with

continuous pilot


Natural gas

and

propane installation code

Note: This

nnex

is

amandatory part of

this

Code

H I

Purging of piping and tubing systems where a

re dily ccessible burner is

not available or where an

appliance

is

not equipped with a continuous pilot shall be undertaken as outlined in Clauses

H 2

to H.7.

H

The procedure shall

be

applicable to

the

purging of air

or

inert gas using natural gas from a piping/tubing

system downstream of th e meter.

H 3

No smoking shall be permitted

when

purging.

H 4

Prior

to commencing

th e purge all sources, or potential sources, of ignition shall be removed or shut off.

H S

The purging procedure shall be used only under the following conditions:

a maximum piping system size is

NPS

1;

b maximum tubing size

is NTS

3/4;

c maximum piping or tubing system gas pressure

is

2 psig 14 kPa ;

d maximum gas pressure at purging point is in w.e. 2.74 kPa or less; and

e

the

longest run of pipe

or

tubing

in

th e system

is

ft 30 m or less.

H 6

Piping

and

tubing systems not meeting th e conditions listed

in

Clause

H 5

shall be

purged

to the

outdoors. Those that do meet these conditions shall be purged in accordance with Clause H.7.

H 7

The purging procedure shall be as follows:

a Use only the

pproved purging assembly. See Figure H.1.

b Inspect

the

purging assembly prior to use. Replace worn or

damaged

hose and ensure that all joints

are tight.

January 2070 45


11/12

Table

H.l

Approximate

purging t imes

a t

7 in

w.e . 1 .74

kPa)

See Clause

H.7.

c Ensure that the manual shut-off valve for

the

appliance

is

closed.

d Connect the purging assembly to the appliance dirt pocket where so equipped, or to th e

appliance

piping, as close to

the appliance

as is practicable.

e Ensure that no sources of ignition are present within th e purge area and that the purge area

is

well

ventilated.

f) Determine th e approximate purging time from Table H.l . Ensure that

the

purge does

no t

exceed

100

s.

g Open

th e

manual shut-off

valve

for

the appliance.

h Begin purging by fully opening the automatic shut-off release purging valve

on

the

purging

assembly. Purge in a continuous and uninterrupted manner. Caution: Under no circumstances shall

the automatic shut-off

release

purging

valve

be fixed

in

the open position.

i) Terminate purging when

the

smell of gas

is detected

a t the purging valve outlet or when th e

approximate

purging time has

been

reached. Do

not

exceed

the

purging time by more

t han lOs .

U When purging is terminated, close the manual shut-off valve and disconnect the purging assembly

from th e piping system.

k)

Reassemble

th e appliance

piping,

open the

manual shut-off

valve

and soap test the affected joints

to ensure that

there

are no leaks.

8749.7 70

246

Pipe/tubing size,

in

NPS

1/2

NPS

1

NTS

1/2

NTS

3/4


Length

of pipe/tubing,

Time

to purge,

f t

m) s

10

3 3

20 6 5

60 18 15

100

30 26

10 3) 7

20 6 14

60 18 43

100

30

84

10

3 1

20 6 2

60 18 6

100 30 10

10 3) 3

20 6 5

60 18 15

100

30 26

January 20

7

a


12/12

anadian

Standards

ssociation

To be

connected to

appliance piping at

dirt pocket

or

as

close

t o t he

appliance

as practicable

NPS

3/4

x NPS

1/2

coupling

Natural gas

and propane

installation

code

Standard tip

NPS 1/4 purging

valve foster

model BG-2l

automatic shut-off

release)

NPS 1/2 Type 1

flexible hose

24 in 600 mm) long)

january 7

Figure

H l

Approved

purging

assembly

See Clause H.7.)

47

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Natural Gas Pipe Sizing Section