☰ Contents · Technology

Water pipes and sewerage

Lessons 9 · 1 lessons · O‘. O. Tohirov, I. Karimov, M. M. Maksimova. Technology (Texnologiya), textbook for Grade 8 of general secondary schools. Ilm Ziyo, Tashkent, 2019
9

Water pipes and sewerage

Textbook: pp. 30–35
GoalKnow the types of water pipes, valve, siphon, water meter, sewerage and the basics of water treatment.
New words
metal-plastic pipe · metalloplastik quvursiphon (trap) · sifonvalve · ventilwater meter · suv hisoblagich
Explanation

In the home, water pipes are mostly made of polypropylene, metal-plastic, polyethylene and metal. Polypropylene pipes are widely used in local water supply and are joined with special fittings and a heated welding tool; this tool runs on the 220-volt mains and its nozzles get very hot, so only the teacher or a master uses it, in protective gloves. A valve stops the flow of water or gas and regulates its pressure (types: globe, plug and ball), and a siphon carries waste water into the sewer and stops smells from rising from it. A water meter measures the amount of cold or hot water used; its body base is blue for cold and red for hot water. Sewerage is divided into household, industrial, rain, drainage and autonomous kinds; waste water is cleaned at treatment plants by chemical and biological methods.

Worked examples
If a meter showed 12 m³ and next month 15 m³, 15 − 12 = 3 m³ of water was used in the month.
The siphon under a sink keeps a layer of water that stops sewer smells getting into the room.
Class activity

Write the pipe types on cards (polypropylene, metal-plastic, polyethylene, metal) and match them with their uses. Then observe the colour of the meter at home (blue or red); do not touch or turn pipes and fittings, and tell adults about any fault.

Practice
1
Which pipes are most used in local water supply?
2
A meter went from 8 m³ to 11 m³. How many m³ of water was used?
3
State the two jobs of a siphon.
4
Why does a pupil not use the welding tool alone?