The sanitary fittings used in the drainage system of houses and buildings include: 1. Wash Basins 2. Sinks 3. Bath Tubs 4. Water Closets 5. Urinals 6. Flushing Cisterns.
1. Wash Basins:
Wash basins are the plumbing fixtures provided for washing hands and face and brushing teeth in a standing position. These are usually made of glazed earthenware or vitreous china. Sometimes these are also made of enamelled iron, stainless steel or plastic, especially where the number of users is more. The wash basins may be of either flat back pattern for fixing on walls, or angle back pattern for fixing at the junction of two walls.
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The standard sizes of these wash basins are as indicated below:
(a) Flat Back Pattern – 630 x 450 mm, 550 x 400 mm, and 450 x 300 mm
(b) Angle Back Pattern – 600 x 480 mm and 400 x 400 mm
A wash basin is an oval shaped bowl of one piece construction including a combined overflow. The overflow is usually of slot type with overflow slot of minimum area 5 cm2 provided at 40 to 45 mm below the top of the basin. The wash basin is provided with double or single tap holes suitable for fixing pillar taps.
It is also provided with a circular waste hole at the bottom for draining the basin. The waste hole is provided with a metallic waste fitting also called waste coupling having a strainer and a clear opening of about 40 mm diameter. A waste pipe with a trap at its bottom is fixed to the waste fitting.
Sometimes the waste pipe is not provided with any trap but it is made to discharge into a floor trap or nahni trap. For holding water in the basin for its cleaning a rubber plug attached to a chain secured by a stay is provided. The chain stay hole is of 10 mm diameter and it is located slightly above the overflow slot.
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The wash basin also has an integral soap holder recess or recesses which drain into the bowl. The wash basin may be supported either on brackets fixed in the wall or on a pedestal rising from the floor. A section of the flat back type wash basin supported on brackets fixed in the wall is shown in Fig. 20.7.
2. Sinks:
Sinks are the plumbing fixtures provided in kitchens for cleaning utensils. These are also provided in laboratories for cleaning laboratory ware. Sinks are usually of rectangular shape and are made of glazed earthen ware or vitreous china, cement concrete with or without terrazzo finish, marble, stainless steel and enamelled iron.
The usual sizes of the sinks are as indicated below:
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(a) Kitchen Sinks:
600 x 450 x 150 mm
600 x 450 x 250 mm
750 x 450 x 250 mm
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(b) Laboratory Sinks:
400 x 250 x 150 mm
450 x 300 x 150 mm
500 x 350 x 150 mm
600 x 400 x 200 mm
The sinks are of one piece construction with or without rim. These are provided with a circular waste hole at the bottom for draining. The waste hole is provided with a metallic waste fitting also called waste coupling having a strainer and a clear opening of about 40 mm diameter.
A waste pipe is fixed to the waste fitting which discharge into a floor trap or nahni trap. The kitchen sinks are usually provided with an overflow arrangement which as shown in Fig. 20.8 is in the form of a circular outlet of minimum diameter 25 mm provided at 30 mm below the top edge of the sink.
The laboratory sinks may be with or without overflow arrangement. The overflow if provided for laboratory sinks is of slot type which is included in the one piece construction of the sink with overflow slot of minimum area 5 cm2 provided at 30 mm below the top edge of the sink. The kitchen sinks are usually provided with a draining board which is fixed on the right side of the user.
3. Bath Tubs:
Bath tubs are the plumbing fixtures provided in the bath rooms for taking bath. These are usually made of glazed earthenware or vitreous china, cement concrete finished with terrazzo or glazed porcelain tiles or marble titles and enamelled iron. The bath tubs are provided with a circular waste hole at the bottom for draining.
The waste hole is provided with a metallic waste fitting also called waste coupling having a strainer and a clear opening of about 40 to 50 mm diameter. A waste pipe with a trap is fixed to the waste fitting. The bath tub is provided with tap/shower and an overflow pipe of diameter 40 mm located at 40 to 50 mm below the top edge of the tub (see Fig. 20.9).
For holding water in the tub a rubber plug attached to a chain secured by a stay is provided. The chain stay hole is of 10 mm diameter and it is located slightly above the overflow pipe. The usual dimensions of a bath tub are: length 1.8 m, width 0.75 m and depth 0.45 m. The overall height of the tub including feet is about 0.6 m.
4. Water Closets (W.C.):
A water closet is a pan like water flushed plumbing fixture designed to receive human excreta directly from the user. It is made of vitreous china or porcelain and is connected to the soil pipe by means of a trap. The inside surface of the water closet and the trap is made smooth by glazing in order to ensure an efficient flush.
The water closet has an integral flushing rim with adequate number of holes to spread the flushing water. The water closet also has an inlet or supply horn for connecting a flushing cistern or a flushing pipe fitted with regulating valve, to flush the water closet and discharge the human excreta to the soil pipe.
Water closets are of the following three types:
(i) Indian type or Squatting type;
(ii) European type of Pedestal type; and
(iii) Anglo-Indian type
Requirements of a Good Water Closet:
The following are the requirements of a good water closet:
(1) It should be convenient for use by persons of all age from a child to an old person.
(2) The size of the closet pan should be such that the urine as well as the faecal matter does not fall outside the pan.
(3) The trap should be such that water in the trap does not splash when the excreta fall in the trap.
(4) Urine should not splash outside the closet pan.
(5) The surface of the closet pan should be smooth so that the faecal matter may flow easily into the trap without sticking to the closet pan.
(6) The closet pan should be such that flushing may be achieved effectively with the use of small quantity of water.
(7) The trap should have an effective and air tight seal.
(8) The closet pan should be so designed that the faecal matter is not too plainly visible before flushing.
(9) The closet pan should be of durable material so that it does not crack with the passage of time.
5. Urinals:
Urinals are the plumbing fixtures provided for the purpose of urinating.
These are usually made of glazed earthenware or vitreous china and are of the following four types:
(i) Bowl type (see Figs. 20.16 and 20.17)
(ii) Slab type (see Fig. 20.18)
(iii) Stall type (see Fig. 20.19)
(iv) Squatting plate type (see Fig. 20.20)
The bowl type urinal is of one piece construction. It may be of either flat back pattern for fixing on a wall or angle back pattern for fixing at the junction of two walls.
The standard sizes of these urinals are as indicated below:
(a) Flat Back Pattern- 430 mm Min. x 260 mm Min. x 350 mm Min
(b) Angle Back Pattern- 340 x 430 x 265 mm
For fixing the urinal on the wall it is provided with at least two holes on each side having a minimum diameter of 6.5 mm. At the bottom of the urinal an outlet horn is provided to which an outlet pipe is fixed which is connected to a floor trap or nahni trap. The inside surface of the urinal is made smooth to ensure efficient flushing. The bottom of the urinal bowl has sufficient slope from the front towards the outlet so that there is efficient draining of the urinal.
The slab type urinal consists of a smooth glazed batter slab fixed on the wall with two end slabs one on either side of the batter slab fixed projecting from the wall.
The standard size of the slab type urinal is as indicated below:
Batter slab- 450 x 1000 mm or 600 x 1000 mm
End slab- 360×1000 mm
About 50 mm portion of the end wall is inserted into the wall for support and the remaining 310 mm portion remains projecting from the wall. Besides the slabs of glazed earthenware or vitreous china, the slabs of cement concrete, slate or marble are also used for the slab type urinals. At the bottom a half-round channel drain is provided along the wall in which urine flows and discharged into a floor trap or nahni trap to which the drain is connected.
The stall type urinal is similar to slab type urinal in which the batter slab and the two end slabs are made of one piece construction. The standard size of the stall type urinal is 1140 x 460 x 400 mm. At the bottom of the urinal an outlet is provided which is connected to a floor trap or nahni trap.
The squatting plate type urinal is also of one piece construction including a drain pipe. The standard sizes of the squatting plate type urinals are 600 x 350 mm and 450 x 350 mm.
The bowl type, slab type and stall type urinals may be used for urinating in standing position while the squatting plate type urinals may be used for urinating in sitting or squatting position. The urinals are usually flushed with siphonic type flushing cisterns which operate automatically at regular interval of 10 to 15 minutes.
The urinals may be installed either as single unit or as multiple units placed side by side. Fig. 20.21 shows the installation of two units of bowl type urinals placed side by side and Fig. 20.22 shows the installation of three units of slab or stall type urinals places side by side.
6. Flushing Cisterns:
Flushing cisterns are the plumbing fixtures provided for flushing out water closets and urinals. These are made of cast iron, glazed earthenware or vitrecous china, or plastic. For Indian type water closets normally cast iron flushing cisterns are used which are fixed with their bottom at a height of 1.25 m above the top of the closet pans and these are known as high level flushing cisterns.
For European type and Anglo- Indian type water closets usually flushing cisterns of vitreous china or plastic are used which are fixed with their bottom at a height of 0.3 m above the top of the closet pans and these are known as low level flushing cisterns.
Flushing cisterns are of two types:
(i) Valveless siphonic type, and
(ii) Valve fitted siphonic type.
The valve less siphonic type flushing cisterns are preferred and are largely used in practice. Bell type flushing cistern is a typical example of the valveless siphonic type flushing cisterns. As shown in Fig. 20.23 a bell type flushing cistern is provided with a central outlet stand-pipe with its upper end projecting a little above the maximum water level in the cistern and its lower end connected to a flush pipe which is connected to the closet pan or urinal.
The stand-pipe is provided with a bell shaped cover called bell which is closed at the top and open at the bottom. The bell is connected to a chain through a lever arm so that on pulling the chain the bell is lifted up and on releasing it the bell is lowered to its original position.
The cistern is filled with water through an inlet controlled by a float valve or ball valve which closes the inlet when the cistern is filled upto the maximum water level and opens the inlet when the cistern is empty thus permitting the entry of water. An overflow pipe is provided to drain out excess incoming water if the float valve ceases to function and thus avoid spilling of water from the cistern in the toilet.
When the chain is pulled the bell is lifted up which splashes the water and a portion of it flows down the stand-pipe. The water flowing down the stand-pipe takes away some air with it which causes a partial vacuum in the upper portion of the bell, thus siphonic action starts and the entire quantity of water in the cistern is sucked rapidly through the large opening at the base of the bell, and the cistern is emptied.
The emptying action takes only a few seconds, causing powerful flush in the water closet or urinal below. When the cistern is emptied the float is lowered which results in opening of the inlet and allowing water to enter the cistern. It may be noted that the chain should be released immediately after being pulled; otherwise the partial vacuum developed may be destroyed by the entry of air from the flush pipe.
The bell type flushing cisterns are usually of 5, 10 and 15 litres capacity.