Page 54 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities
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PIPING
2.4 CHAPTER TWO
Corrosion failure occurs if any pipe material is reduced to a minimum thickness man-
dated by code.
Manufacturers of pipes and fittings publish corrosion-resistance tables concerning
chemical resistance and compatibility with fluids carried by the piping they produce. These
relate to temperature, concentration, and specific chemicals. These tables should be used
for selection of a specific pipe to transport any specific chemical.
PHYSICAL STRENGTH
Physical strength is the capability of any pipe to resist the damage that might occur either
during the construction phase or after the pipe is placed in service.
FIRE RESISTANCE
Fire resistance is the capability of a piping system to simply remain intact and not fall dur-
ing a fire or, in some cases, to also retain the ability to carry water. Where this is a factor,
pipes, joints, and supports strong enough for this purpose should be selected.
AVAILABILITY
Any pipe is considered available when it can be supplied at a competitive price to the area
where the project is under construction. In addition, obtaining the mechanics and special
tools needed to assemble the piping system must also be possible.
METALLIC PIPE AND PIPING MATERIALS
ALUMINUM (AL)
Aluminum pipe is manufactured in various wall thicknesses similar to copper and in sizes
ranging from 1/8 to 12 in. Sizes above 3 in are not readily available. Aluminum is manufac-
tured in various alloys; the most commonly used for facilities conforms to ASTM B-210.
Joints are made using brazing or welding with special aluminum alloy filler metals.
Aluminum tubing is light in weight and generally used for specialty services, such as
cryogenics (where ductility and strength are necessary) and for carrying compressed spe-
cialty gases (because of its corrosion resistance). It also resists many specialty chemicals
and is resistant to atmospheric corrosion. It is not suitable for acids, mercury, and strong
alkalis. It has a high rate of expansion.
For a list of various alloys, refer to Table 2.2.
BRASS (BR)
Brass is an alloy of copper and zinc. The proportion varies from 85% copper to 67% copper.
Pipe with a high copper content is known as red brass, and that with a lower content is
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