WATER SUPPLY SYSTEM IN HIGH RISE BUILDING

WATER SUPPLY SYSTEM IN HIGH RISE BUILDINGS

Have you ever wondered how is water transported to the highest point of the tallest building in the world – The Burj Khalifa? What kinds of pumps and systems are ‘powerful’ enough to supply water up to a height of 828m vertically from the ground level? The key is booster.

Figure 1: How does water go up yo the tip of The Burj Khalifa? (Source: Groupon)

In the early days, a tank was placed on top of the tall buildings and a few constant speed pumps were required so that the water could be supplied to the upper floors. However, roof tank incurred some challenges, such as the need of a super huge tank to cater a large population, and hygienic issues in which birds often nest near the tank although it’s covered up. Eventually, in 1950s, community began to innovate and came up with the idea to replace the roof tank with a tank on the floor level but still it required some pumps to keep it operated. This system is costly to install yet consume a large amount of energy in order to provide a required constant pressure. With the chronological improvements and innovations, booster systems are used in today’s high-rise buildings.

Figure 2: Booster system (Source:Google )

Systems for boosting water pressure 

Pressure- boosting systems can be of several different types:

• Pumping from a ground level or basement gravity tank to a gravity roof tank
• Pumping from a gravity storage tank or public water main into a hydropneumatic pressure tank that uses captive air pressure to provide adequate drinking-water supply pressure
• Installation of booster pump sets consisting of multiple staged pumps or variable speed pumps that draw water directly from a gravity storage tank or the public water main .

System Configuration 

Figure 3: Single booster system (Source: Google)

1. Single booster system. 

A water tank is placed in front of the pump system and filled with water from the mains. This allows the capacity of the mains to be lower than the building’s peak demand, ensuring constant pressure even in peak flow situations. The break tank is filled with water during low consumption periods and ensures a uniform water supply to the booster pumps at all times.

Advantages	Disadvantage
No space required for boosters    on   upper levels   Only one (or a few) riser pipe(s) in the building	High static pressure booster pump system Pressure relief valves have       to be fitted High operational costs High pressure-graded pipes an booster sets Sensitivity to electricity fall outs

Figure 4: Zone- divided system (Source: Google)

2. Zone-divided system. 

The supply system is split into several zones supplying a maximum of 12 floors each. This ensures adequate water pressure on all floors without using pressure relief valves. The minimum pressure on the upper floor in each zone is kept at 1.5 - 2 bar. The maximum pressure on the lowest floor in each zone does not exceed 4 - 4.5 bar.

Advantages	Disadvantages
Only the required water pressure is supplied  No space required for boosters on upper levels   Less vulnerable in the event of pump failure  No pressure reduction valves	More riser pipes in the building High pressure-graded pipes and boosters sets Sensitive to electricity fall-outs

Figure 5: Roof tanks (Source: Google)

3. Roof tanks 

Roof tanks ensure both water pressure and water supply in case of power failure. This solution requires pressure reduction valves on each floor in order to avoid undesired high static pressures at the tap, which creates unacceptable noise while tapping. In this model the upper six floors require a separate booster system in order to create sufficient pressure. The static pressure there is too low due to the insufficient geometric height to the roof tank.

Advantages

Disadvantages

· Mature technology             · Only one discharge from           booster set to top          ·  Space saving          · Less sensitive to electricity          fall outs

·Water is pumped past where it’s           required            · Insufficient pressure on the                  uppermost floors           · Excessive pressure on the                   lowest floors           ·  Pressure reduction valves                   have to be fitted           ·   Need for higher pressure grade          of pipe work      ·   Space requirement for tank           ·   Risk of microbiological growth           in roof tank

4. Series-connected systems 

This system with intermediate break tanks draw on several other systems, utilizing centrally-placed break tanks to supply both the taps in its own boosting zone and all the zones above it. With this system, a building is divided into smaller and more manageable pressure zones of 12 floors each. Every zone is then served by its own booster set. No pressure reduction valves are required and in case of electrical breakdown the tanks will be able to supply pressure and water for up to 12 hours. However, the tanks take up valuable space within the building, reducing the room available for revenue generation.

  

Advantages	Disadvantages
·  Low cost operation         ·         Low pressure in each zone                   ·         Manageable pressure zones         ·         High resilience          ·         Low power consumption of                  pumps and reduced load power              grid        ·         Less sensitive to electricity fall              out	·    High initial investment         ·  Booster sets and tanks require space        on service floors         ·  Lost potential revenue generating           space

COMMON PIPING AND PLUMBING FITTINGS

Elbow

An elbow is installed between two lengths of piping to allow a change of direction. 90° or 45° elbows are available and common in use.

              

     

                                                             

Short-radius 45° elbow                       Long-radius 90° elbow                                                                                                                                                             

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Coupling

A coupling connects two pipes. If their sizes differ, the fitting is known as a reducing coupling, reducer, or an adapter.

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Union

A union, similar to a coupling, allows the convenient future disconnection of pipes for maintenance or fixture replacement.

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Tee
A tee, the most common pipe fitting, is used to combine fluid flow. Tees can connect pipes of different diameters or change the direction of a pipe run, or both.

(Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting) 

Cap

A cap attaches to the exterior of a pipe, and may have a solvent-weld socket end or a female-threaded interior.

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Nipple

A nipple is a short stub of pipe, usually male-threaded steel, brass, chlorinated polyvinyl chloride (CPVC), or copper (occasionally unthreaded copper), which connects two other fittings.

(Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Crimped fittings

Crimped or pressed connections use special fittings which are permanently attached to tubing with a powered crimper. The fittings, manufactured with a pre-installed sealant, slide over the tubing to be connected. High pressure is used to deform the fitting and compress the sealant against the inner tubing, creating a leak proof seal.

 

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Flange fittings

Flange fittings are generally used for connections to valves, inline instruments or equipment nozzles.

(Sources: Swagelock)

Mechanical fittings

Mechanical fittings are replacing many flange connections. They attach to the end of a pipe segment via circumferential grooves pressed around the end of the pipe to be joined. They are widely used on larger steel pipes, and can also be used with other materials.

 (Sources: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting)

Valves

A valve is a device that regulates, directs or controls the flow of a fluid such like liquids by opening, closing, or partially obstructing various passageways. Valves are technically fittings, but are usually discussed as a separate category. Valves used in water supply systems can be subdivided into two function groups: Shut-off valves and control valves.

(Sources: Wikipedia)

Components of valve:
1. Body 

2. Ports
3. Seat
4. Stem
5. Disc when valve is open
6. Handle or hand wheel when valve is open
7. Bonnet
8. Packing
9. Gland nut
10. Fluid flow when valve is open
11. Position of disc if valve were shut
12. Position of handle or hand wheel if valve were shut

Types pf valves

Sluice Valves / Gate Valves

A sluice valve also known as a gate valve, is a valve which opens by lifting a round or rectangular gate/wedge out of the path of the fluid.

(Sources:https://en.wikipedia.org/wiki/Gate_valve)

Globe Valves

Globe valve is different from ball valve, is a type of valve used for regulating flow in a pipeline, consisting of movable disk-type element and a stationary ring seat in generally spherical body.

        (Sources:https://en.wikipedia.org/wiki/Globe_valve)

Air Valves

Air valve used to release this free air is known as an air release valve.

(Sources:Air Valves | 36 Series Combination Air Valve)

Relief Valves   

A relief valve is a type of safety valve used to control or limit the pressure in a system.

 (Sources:Safety Relief Valves)

Float Valves

Float valves is a mechanism or machine for filling water tanks, such as those found in flush toilets.

 (Sources:Solenoid Valve World)

Butterfly Valves 

Butterfly valves allows for quick shut off. The disc is positioned in the centre of the pipe. A rod passes through the disc to an actuator on the outside of the valve. Butterfly valves are generally favoured because they cost less than other valve designs, and are lighter weight so they need less support.

(Sources: https://en.wikipedia.org/wiki/Butterfly_valve)

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