THERMAL EXPANSION

Thermal expansion can occur in pipes when there are temperature fluctua­tions. Damage can result from this expansion if the pipe is not installed prop­erly. In order to avoid damage, refer to Figures 11.7, 11.8, and 11.9 to learn about the tolerances needed for various types of pipe (Fig. 11.10).

THERMAL EXPANSION

Coefficient

Pipe material

in/in/°F

(°С)

Metallic pipe

Carbon steel

0.000005

(14.0)

Stainless steel

0.000115

(69)

Cast iron

0.0000056

(1.0)

Copper

0.000010

(1.8)

Aluminum

0.0000980

(1.7)

Brass (yellow)

0.000001

(1.8)

Brass (red)

0.000009

(1.4)

Plastic pipe

ABS

0.00005

(8)

PVC

0.000060

(33)

PB

0.000150

(72)

PE

0.000080

(14.4)

CPVC

0.000035

(6.3)

Styrene

0.000060

(33)

PVDF

0.000085

(14.5)

PP

0.000065

(77)

Saran

0.000038

(6.5)

CAB

0.000080

(14.4)

FRP (average)

0.000011

(1.9)

PVDF

0.000096

(15.1)

CAB

0.000085

(14.5)

HDPE

0.00011

(68)

Glass

Borosilicate

0.0000018

(0.33)

FIGURE 11.7 ■ Thermal expansion of piping materials. (Courtesy of McGraw-Hill)

Temperature Change (°F)

Length (ft)

40

50

60

70

80

90

100

20

0.278

0.348

0.418

0.487

0.557

0.626

0.696

40

0.557

0.696

0.835

0.974

1.114

1.235

1.392

60

0.835

1.044

1.253

1.462

1.670

1.879

2.088

80

1.134

1.392

1.670

1.879

2.227

2.506

2.784

100

1.192

1.740

2.088

2.436

2.784

3.132

3.480

Подпись: Temperature Change (°F) Length (ft) 40 50 60 70 80 90 100 20 0.536 0.670 0.804 0.938 1.072 1.206 1.340 40 1.070 1.340 1.610 1.880 2.050 2.420 2.690 60 1.609 2.010 2.410 2.820 3.220 3.620 4.020 80 2.143 2.680 3.220 3.760 4.290 4.830 5.360 100 2.680 3.350 4.020 4.700 5.360 6.030 6.700

FIGURE 11.9 ■ Thermal expansion of all pipes (except PVC-DWV). (Courtesy of McGraw-Hill)

Подпись: A hole in a pipe that is not more than .63 centimeters in diameter can result in a loss of 14,952 gallons of water a day! Even a pinhole leak can amount to a loss of over 18,000 gallons of water in a three-month period.

FIGURE 11.10 ■ Tech tips.

Updated: 23 ноября, 2015 — 7:39 дп