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CHAPTER IV OBSERVATION

4.1 Pipelines and Risers

A 100mm riser and 4 down feeds having diameters of 100mm, 75 mm,50mm,and 40mm,

made up of galvanized steel iron pipe, standard Schedule 40, were installed to carry water from

underground reservoir to the elevated tank and to convey water to the water line branches

respectively. The riser was screwed connected from underground tank extending to the 23 rd floor

of the building where the pump room and elevated water tank is located. The pipe on the most

left (see Fig 4.1) is the down feed noted in the plan as CWDF-2 (see Appendix) supply water to

the ground floor to the 20 th floor for the typical one-bedroom units. It is connected to the water

meter assembly in each floor. The blue GI pipe in the middle is the riser supplying the tank onthe tank room. A separate down feed is used to convey water for penthouse units of 21 st to 23rd

floors. The schematic riser diagram of the cold water lines is shown in figure 4.2.

Figure 4.1 Risers and Down feeds

100 Riser

100 Down feed

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Distribution for hot and cold water lines and roughing-ins of toilets are made up of cross-linked

polyethylene (XLPE) with aluminum reinforced aluminum composite pressure pipes standard

with diameters of 25mm for branches and 16mm for unit fixture lines (see Figure 4.2). The lines

are connected by push-on type brass coated fittings. Pipe hangers, inserts and supports are made

up of adjustable wrought iron or malleable iron pipe hangers that are spaced not over 3m apart.

Figure 4.3 shows different kinds of hangers and sleeves used in installation of pipes while Figure

4.4 shows hangers for horizontal distribution lines.

Figure 4.3 Cross-linked polyethylene fordistribution lines

Figure 4.4 Kinds of hangers, inserts and sleeves used in La Vie Flats

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Figure 4.5 Hangers for horizontal distribution lines

4.2 Valves and Pipe Fittings

Gate valves used in the site are rising-stem type gate valves. 75mm and larger sizes gate valves

with iron body with bronze trim and are flanged connected and with a minimum working

pressure is 150 psig, while for 65mm and smaller gate valves are all bronze female threaded and

has minimum working pressure of 150 psig. 100mm gate valves are installed next to pumps,

tanks and to the pressure reducing valve for shutting-off, while the 65mm gate valves where

installed usually in the water meter assemblies. (See figure 4.5)

Figure 4.6 - 75mm gate valves installed on basement 4above the underground reservoir tank

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4.3 Water meter assembly

Each floor has their main pipe chase where the risers, down feeds, drainage pipe and garbage

chute vertically pass through. The main pipe chase houses the water meter assembly. The water

meter assembly consists of 12 gate valves and water meter for typical floors, and 8 gate valvesand water meter for pent house floors. For detailed drawing of water meter assembly see

Appendix-

4.4 Hydropneumatic Tank

The hydro pneumatic tank is vertically mounted on the roof deck in the pump room as shown in

figure 4.7. It has a capacity of 550 US gallons with operating pressure cut in at 35 psi and cut off

at 55 psi. It was made up of 3/16 stainless steel that is properly drained and cushioned. It was

provided with pressure gage and water level gage. A pressure relief valve will be installed so that

the pressure will exceed to 60 psi.

4.5 Elevated Cylindrical Water Tank

Figure 4.7 Hydropneumatic Tank

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The elevated cylindrical water tank with a capacity of 15 gallons was mounted on a concrete

saddle beside the pump room on the roof deck. The Water tank was divided into two partitions,

connected with an equalizing gate valve with a diameter of 100 mm. The water tank is connected

on the gravity supply down feed and to the pneumatic system. The water tank was equipped

with a water level indicator and a steel ladder rung. Figure 4.8 shows the as built drawing of the

elevated water tank. (See appendix)

The water tank is made up of 8 sheets of 4 ft x 8ft steel sheets of 400mm thick weighing 300 kg

per sheet. It was pre-fabricated into 5 pieces and delivered in the site using two boom trucks.

Hoisting was done through the use of tower crane. Pictures in figure 4.8 show the actual hoisting

of the tank.

To keep the cylindrical shape of the tank, cross 2x2 angular bars steel reinforcement is used for

interior support. The cross is full welded on the tank with stainless weld. The tank was

assembled by full welding it from inside and outside with stainless steel weld. Additional

appurtenances and fittings were installed including the water level indicator and ladder rung.

4.6 Pressure Reducing Valve Assembly

Figure 4.8 Hoisting of the pre-fabricated parts of the water tank (left) and mounting of thewater tank parts on the concrete saddle (right)

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The pressure reducing valve assembly is located at the main pipe chase at the 10 th floor of the La

Vie flats building. It consists of 2 two unit pressure reducer valves with threaded gate valves and

wye strainers. It is connected in series with the cold water line down feed.

Figure 4.9 Pressure Reducing Valve Assembly