Pipes and Fittings

Question 1

Cast Iron Pipe

Answer 1

-most popular and generally specified material for drainage installation
-extensively used in the 60s and 70s
-durable, conveniently installed (<25 storey)
-commercial length: 600cm
-diameters: 50 - 150mm
-affected to some extent by corrosion by acid formed by carbon dioxide, sulfur oxide, and methane gases that create rust

Question 2

2 Types of Cast Iron Pipe

Answer 2

SV (Service) Type and XH (Extra Heavy) Type

Question 3

Generally used for building installations

Answer 3

SV Type

Question 4

Extra duty for underground installations

Answer 4

XH Type

Question 5

Acid Resistant Cast Iron Pipe

Answer 5

-made of an alloy of cast iron and silicon
-installed in chemical laboratories, industries and other installations where acid wastes are being discharged
-brittle and cracks easily, thus horizontal runs have to be supported at every 1.5m interval to prevent sagging

Question 6

Asbestos Pipe

Answer 6

-made of asbestos fibers and portland cement
-used as soil, waste, ventilation pipe and downspouts
-suited for concrete embedment because of similar properties

Question 7

Vitrified Clay Pipe

Answer 7

-one of the oldest materials used for sewer lines
-highly resistant to most acids
-because it is made of clay, it is brittle and cracks easily when laid on unstable ground
-made in short lengths of 750mm

Question 8

Bituminous Fiber Sewer Pipe

Answer 8

-cheapest of all types of pipes
-light in weight, slightly flexible and can take slight soil movement without danger of cracking or pulling out of its joints. It is thus suited for house sewer and septic tank installations
-may be softened/damaged by excessive hot water or chemical flow

Question 9

Galvanized Steel Pipe

Answer 9

-made out of mild steel and expected to last 15 to 25 years
-subject to deposits of salt and lime
-comes in several commercial sizes:
10 (3/8”), 13 (1/2”), 20 (3/4”), 25 (1”), 32 (1-1/2”), 38 (1-1/2”), 50 (2”), 75 (3”), 100 (4”)

Question 10

Brass Pipe

Answer 10

-most expensive
-made of an alloy of zinc (15%) and copper (85%)
-resistant to acids and has a smooth interior surface

Question 11

Galvanized Wrought Iron Pipe

Answer 11

-better than steel pipe for plumbing installation
-more resistant to acid wastes

Question 12

Lead Pipe

Answer 12

-the oldest pipe used for plumbing systems
-highly resistant to acid
poisonous and injurious, is therefore not recommended to convey water for human consumption

Question 13

Copper Pipe

Answer 13

-durable and extremely corrosive resistant
-easy to install; smooth interior surface

Question 14

Classification of Copper Pipe

Answer 14

K, L, M

Question 15

K Type

Answer 15

• heaviest
• recommended for underground installations

Question 16

L Type

Answer 16

• lighter; available in both rigid and flexible form
• recommended for water supply line and radiant heating installations

Question 17

M Type

Answer 17

• thinnest; available only in rigid form
• for small water supply lines and radiant heating installations

Question 18

Plastic/ Synthetic Pipe

Answer 18

-developed in Germany in 1935
-most are produced from synthetic resins
-superior type of pipe because it weighs less, is easy to cut, is flexible, has a smooth interior surface and is cheaper than steel

Question 19

2 types of Plastic Pipe

Answer 19

Rigid Type (Pipes) and Flexible Type (Tubing)

Question 20

Consideration in choosing materials

Answer 20

Quality and durability

Resistance to external and internal contact with foreign matters

Resistance to acid waste and other chemical elements that will pass into it

Cost of materials and labor

Question 21

Tightness

Answer 21

perform pressure test on joints and connections of pipes and fittings to ensure gastight and watertight connections