WATER SYSTEM

UNIT-5

           

                        Water System

 

There are three main sources of water :

1- Rain

2- Surface water : Oceans, Rivers and streams , tanks , ponds & lakes

3- ground water : shallow wells, Deep wells , Springs

1. Rain

Rain is the prime source of all water. A part of the rain water sinks into the ground to form ground water; part of it evaporates back into atmosphere, and some runs off to form streams and rivers which flow ultimately into the sea.

Some of the water in the soil is taken up by the plants and is evaporated in turn by the leaves. These events are spoken of as "water cycle".

Characteristics of rain water:-

Rain water is the purest water in nature. Physically, it is clear, bright and sparkling. Chemically, it is very soft water containing only traces of dissolved solids (0.0005 percent).

Being soft, it has a corrosive action on lead pipes. Bacteriologically, rain water from clean districts is free from pathogenic agents.

Impurities of rain water:

Rain water tends to become impure as it passes through the atmosphere. It picks up suspended impurities from the atmosphere such as dust, soot and microorganisms and gases such as carbon dioxide, nitrogen, oxygen and ammonia.

Gaseous sulphur and nitrogen oxides are emitted from power plants that use fossil fuels. These gases react with atmospheric water, forming dilute solution of sulphuric and nitric acid. The precipitation of these acids (acid rain) has begun to have serious impacts on surface water quality and on plants etc..

2. Surface water

Surface water originates from rain water. It is the main source of water supply in many areas. Examples of surface water include rivers, tanks, lakes, man-made reservoirs and sea water.

Surface water is prone to contamination from human and animal sources. As such it is never safe for human consumption unless subjected to sanitary protection and purification before use.

Characteristics of surface water:

Surface water picks up the characteristics of the surface over which it passes. If water flows across a parking lot, gasoline, oil, and other contaminants may be carried by or dissolved into the water.

Water may pick up fertilizers, road salts, radioactivity, and biological contaminant from farms, as well as countless other biological, physical, and chemical pollutants.

Rivers:

Many rivers furnish a dependable supply of water. The chief drawback of river water is that it is always grossly polluted and is quite unfit for drinking without treatment.

Characteristics of river water:

River water is turbid during rainy season; it may be clear in other seasons. Clarity of water is no guarantee that the river water is safe for drinking. River water contains dissolved and suspended impurities of all kinds. The bacterial count, including the human intestinal organisms may be very high.

Impurities of river water:

The impurities of river water are derived from surface washings, sewage and sullage water, industrial and trade wastes, and drainage from agricultural areas.

Self-purification of river water:

Certain amount of self-purification occur in river water by natural forces of purification such as dilution, sedimentation, aeration, oxidation, sunlight, plant and animal life ,but these agencies are not sufficient to render the water potable. River water needs purification before it can be used for drinking purposes.

Sea water:

Though this source is plentiful, it has great many limitations. It contains 3.5 percent of salts in solution. Desalting and demineralization process involves heavy expenditure. It adopted in places where sea water is the only source available.

3. Ground water

Rain water percolating into ground constitutes ground water. Water used by humans comes mainly from land. It is now realised that there is a limit to ground water in the world.

Ground water is the cheapest and most practical means of providing water to small communities. Ground water is superior to surface water, because the ground itself provides an effective filtering medium.

The advantages of ground water are:-

(1) It is likely to be free from

pathogenic agents;

(2) It usually requires no treatment;

(3) The supply is likely to be certain

even during dry season;

(4) It is less subject to contamination than surface water.

The disadvantages of ground water are:

(1) It is high in mineral content, e.g.,

salts of calcium and magnesium which increase the water hard;

(2) It requires pumping or some arrangement to lift the water.

Wells:

Traditionally wells are an important source of water supply. Even today, they are an important source of water supply in many communities. Technically, wells are of two kinds-shallow and deep.

(1) Shallow wells:

shallow wells tap subsoil water i.e. the water from above the first impervious layer in the ground. They provide limited quantities of water, and the water is easy to be polluted unless care is taken in well construction.

(2) Deep wells:

A deep well is one which taps water from the water-bearing stratum below the first impervious layer in the ground. Deep wells are usually machine-dug and may be several hundred meters deep. Deep wells furnish the safest water, and are often the most satisfactory sources of water supply.

Springs:

When ground water comes to the surface and flows freely under natural pressure, it is called a "spring". Springs may be of two types------shallow springs and deep springs. Shallow springs dry up quickly during summer months, whereas deep springs do not show seasonal fluctuations in the flow of water.

In some geographic areas, springs constitute an important source of water. Springs are simpler to exploit, as no pumping is needed to bring the water to the surface. Springs are exposed to contamination.

Method Of Removing Hardness

One of the common methods of removing hardness is by means of soap. When a soap, which is made with potash and soda as a base, is added to the water containing calcium and magnesium salts the soap is decomposed, and the fatty acid is set free in an insoluble state. It is upon this reaction that the old method of determining hardness, known as Clark's method, was based. This process has been varied in many ways by chemists in different countries, but the original principle has not been departed from.

The hardness is usually estimated in the number of milligrams of calcium carbonate in a standard volume of water - usually 100,000 parts. In England and America it is usually determined by the number of grains of calcium carbonate in an imperial gallon in England and a United States gallon in America, which means, in England, the number of grains of calcium carbonate in 70,000 parts, and, in America, in 58,381 parts.

 

Removal of Hardness

By boiling the hard water

On boiling calcium / magnesium bicarbonate decompose salts, which are normally present in portable water.  These are called hard salts due to two factors

1.     When hard water is heated, salts will frequently precipitate out causing a lime build within pipes and around plumbing fixtures or deposits on items being washed.

2.    When water containing these salts is mixed with natural soap and some synthetic cleaners, the salts ombine with cleaner chemicals and precipitate onto and within the products being washed. The resulting mixture is called soap curd, a sticky substance that is difficult to remove from washed products.

 

 

calcium/magnesium carbonate, which is insoluble in water. Therefore, it precipitates out.

By the addition of slaked lime (Clark's process)

In Clark's process, slaked lime, Ca(OH)2 is added to temporary hard water. Insoluble calcium carbonate precipitate out and no longer produce hardness.

The methods used to remove permanent hardness given in the next section can also be employed to remove the temporary hardness. However, the above methods cannot be used to remove the permanent hardness.

Methods to Remove Permanent Hardness

By the addition of washing soda (sodium carbonate)

Calcium and magnesium ions present in hard water react with sodium carbonate to produce insoluble carbonates. The water now contains soluble and harmless sodium salts.

Calgon process

Calgon is a trade name of a complex salt, sodium hexametaphosphate

(NaPO3)6. It is used for softening hard water. Calgon ionizes to give a complex anion:

The addition of Calgon to hard water causes the calcium and magnesium ions of hard water to displace sodium ions from the anion of Calgon.

This results in the removal of calcium and magnesium ions from hard water in the form of a complex with Calgon. The water is softened and sodium ions are released into water.

By the ion-exchange process (Permutit process)

Permutit or sodium aluminium silicate is a complex chemical compound, which occurs as a natural mineral called Zeolite. Permutit or zeolites are insoluble in water and have the property of exchanging ions present in them with the ions present in the solution.

Permutit or zeolites are packed in a suitable container and a slow stream of hard water is passed through this material. As a result, calcium and magnesium ions present in hard water are exchanged with sodium ions in the permutit (Na+Al-Silicate). The outgoing water contains sodium salts, which do not cause hardness.

Regeneration

Over a period of time permutit gets converted into a mixture of calcium and magnesium aluminium-silicates and permutit has to be regenerated for further use. This is done by packing brine - a concentrated solution of sodium chloride, through the column packed with spent permutit. The following reactions take place.

The resulting calcium chloride and magnesium chloride produced, are washed out through a tap at the bottom. The regenerated permutit is reused for softening water.

By the use of ion-exchange resins

Giant organic molecules having acidic or basic groups are known as Ion-exchange resins. Acid resins contain the acid group (- COOH). Basic

resins contain the basic group [(-NH)OH-], i.e., substituted ammonium hydroxide group. Acid and basic ion exchange resins are represented as RCOO-H+ and RNH + OH- respectively.

Acid resins exchange their H+ ions with other cations such as Ca2+, Mg2+, etc., present in hard water. Acid resins are, therefore known as base-exchange resins.

Basic resins exchange their OH-ions with the other anions such as HCO3-, Cl-, SO42-, present in hard water. Basic resins, therefore, are also known as acid exchange resins.

Ion-exchange process for water softening

In the ion exchange process, hard water is passed through two tanks

'A' and 'B'. Tank- A contains acid resin and tank- B is filled with basic resin. All the cations present in hard water (except H+) are removed by the acid resin present in Tank- A, and the basic resin present in Tank- B removes all the anions (except OH-) present in hard water. Water obtained after passage through both the tanks is free from all the cations and anions that make it hard. The water obtained after passing through the ion-exchangers is called deionised water or demineralised water. This is as good as distilled water. The water becomes soft after this process.

Regeneration

After some time, the resins require regeneration as they become ineffective. Adding a strong acid regenerates acid resin and the basic resin is regenerated by treating it with a solution of a strong base.

 

The regenerated resins are washed to remove Ca2+, Na+, SO, Cl-etc. The resins can be used again. The water treated by ion-exchange process not only becomes soft but also free from all dissolved mineral impurities. It gets completely demineralized.

Problem

4. Given that a sample of water has degree of hardness equal to 40 ppm. If the entire hardness is due to MgSO4. How much MgSO4 is present per kg of water?

Solution

The degree of hardness of water is defined as the number of parts by mass of calcium carbonate, equivalent to various calcium and magnesium present in one million parts of mass of water. It is expressed in ppm.

Now, 106 g of water contains CaCO3 = 44 mg

By definition, 1 mol of CaCO3 = 1 mol of MgSO4         

Or, 100 mg of CaCO3 = 120 mg of MgSO4

Therefore 48 mg of MgSO4 is present in 1 kg of water.

Hot And Cold-Water System

Hot and cold-water supplies from the engine room in the cellar, as shown in the accompanying view of the valve board, heater, and main connections, the pipes and valves being set to meet previous conditions, and conveniently and compactly arranged with symmetry on the walls and low ceiling.

HOT AND COLD-WATER SYSTEM IN A HOTEL.

Hot Water Supply. Cylinder System

In the cylinder system the principal difference from the tank system lies in the fact that the cylinder or reservoir of hot water lies beneath the draw-off pipes and not above them, as with the tank system. This being the case it is impossible to empty the reservoir unknowingly or accidentally, should the cold water supply be shut off.

From the top of the boiler is carried the expansion pipe. This also should rise 1 inch in 10 feet from the boiler to its highest point. The highest point can be above the cold water cistern or through the roof.

The cold water supply to the system is a pipe direct from a cistern, as shown. This pipe must not be branched for any other purpose.

It is of the highest importance that the cold water supply pipe should be of full size, and not choked or reduced in bore anywhere. The outflow at the hot water faucet is exactly in ratio with the down-flow of water through this pipe, less friction, therefore everything possible must be done to give the water full and free passage and lessen the friction. This is done by having the pipe of good size, using bends and not elbows, or lead pipe, and seeing that the stop-cock, if there be one, has a straight full way through it. The stop-cock should be put near the boiler, so that the man who cleans the waterback, or effects repairs, does not have to traverse the house to shut the water off and afterwards to turn it on. A tee should be put on the cold water supply connection, inside the boiler to spread the inflowing cold water over the bottom of the boiler. If this is not done the inflowing cold water will bore its way up through the hot water above, unless the pressure be quite low.

An emptying cock should be put somewhere beneath the boiler, but this cock must be provided with a loose key, so that only an authorised person can withdraw the water from the boiler.

The draw-off pipes are all taken from the expansion pipe as shown. This pipe should therefore be carried up by the best route to touch at the points where the faucets are, otherwise long single branches must be run. The expansion pipe, being a single tube, has no active or useful circulation in it.

It must never be forgotten that, on opening a faucet, on a secondary circulation, water will proceed from both directions to reach that faucet. The circulatory movements all cease, and quite a new action takes place. Water will come up from the top of the boiler and this will be hot.

 Overhead System of Hot Water Supply for Office or Apartment Building.

Fig. 315. - Hot-Water Supply for Office or Apartment Building.

 Section of Double Boiler.

In selecting the proper system of hot-water supply for a large building, as much judgment is needed as in the selection of the proper system of heating.

While one system under certain circumstances and conditions will perforin excellent service, another will fail entirely. If the plumber is well grounded in the principles of circulation, and a man of practical experience, he will usually be able to determine what system of supply under the given conditions will give the best results.

 Hot Water Supply from Double Boiler.

The double boiler is a device which finds an important application in the hot-water supply systems of many high buildings in the large cities. It is very seldom used, however, in any but the largest cities.

Sectional view of the double boiler, from which it will be seen that it consists of two boilers, one inside the other. The outer boiler is heated in the usual manner, and the inner boiler is heated by contact with the heated water of the outer boiler. The outer boiler is under direct pressure, and the inner boiler under tank pressure. It will be readily considered that in high buildings, running up many stories, the upper floors are sometimes above the height at which water under city pressure can reach. Even though this condition is not permanent, it often happens that during certain times of day the pressure which at other times is sufficient is so reduced that it cannot force water to the higher floors. It is under these conditions that the double boiler is made use of,

 Simple Form of Cut-off.

The inner boiler supplies hot water to the upper floors under tank pressure, and the outer boiler supplies the lower floors under street pressure.

The attic storage tank must generally be supplied by means of a pump or water lift.

- Automatic Cut-off.

The cross connection between the two boilers allows both to be fed with street pressure when the latter is high enough to reach the upper floors. At night when the pressure is high, this course may be adopted, thus saving the expense of pumping to the tank.

simple form of cut-off, a device often employed on double boiler work for the purpose of delivering into the distributing pipes a supply of water under either tank pressure or direct pressure, as the case may be.

The successful operation of this cut-off is entirely dependent on the attention and caution of the attendant in the opening and closing of the proper valves, and the occasional lack of care has resulted in casting this device away for automatic cut-offs, such as the one of Fig. 319.

In the latter, each of the four valves is rigidly attached to a system of levers, operated by a handle, the throwing of which either opens or closes the proper valves, thus obviating any mistakes.

The same work that is accomplished by the double boiler may be performed by two single boilers connected in the proper manner, as seen in Fig. 320.

In order to run the two boilers under different pressures the water front of each must be entirely separate from that of the other. Separate coils in the same heater may be used for this purpose. Special heaters having two separate heating surfaces may also be used. The general connections for this system are quite similar to those of Fig. 317. One boiler supplies the upper floors, and is therefore under tank pressure, while the other supplies the lower floors under street pressure.

It may be stated that double-boiler work is taken up by the author in his work entitled "Modern Plumbing Illustrated."

A very common difficulty that is encountered in many sections of the country, especially in the West, is the accumulation of lime in the range connections and piping. This trouble is serious enough in connection with the procuring of hot-water supplies for residences and dwellings, but in the case of larger work, such as public or semipublic buildings, its existence results in much greater annoyance.

In some localities the only natural supply of water that can be obtained is hard water, strongly impregnated with lime, which it takes up in its passage through the soil. The depositing of lime takes place principally in hot-water pipes, although it also occurs in the cold-water pipes. When the lime has once begun to accumulate on the interior of a pipe, the accumulation increases rapidly, and often in a comparatively short time the pipe will become entirely filled. This condition is not only a source of much annoyance, but a source also of danger.

Many attempts have been made to clear pipes thus filled with various substances, but even though sometimes partially successful, such a cure does not produce permanent results. It is usually more satisfactory to replace the filled pipe with new pipe rather than to attempt to clean out the lime deposit.

Hot And Cold Water Supply

How high can water be raised by atmospheric pressure?

Theoretically, a little more than thirty-three feet, but practically, the friction of the pipes, bends, etc., tends to reduce this height, so that it is not usually safe to count on more than twenty-eight feet, and sometimes not more than twenty-five feet. .

Describe the method of supplying a cistern hot water boiler.

This style of boiler receives its supply from a tank situated above the boiler, usually in the attic.

Describe the method of supplying a pressure hot water boiler.

This boiler is supplied directly from the city water main. Being usually under a very heavy pressure, it must be made extra strong.

Which hot water boiler is more susceptible to syphonage, and why?

The pressure boiler is more likely to syphon, and for the following reason: The boiler is always at a point higher than the street main.

What is a vacuum valve?

A valve placed upon the supply pipe to the boiler, which is made tight from internal pressure, but upon the pressure being withdrawn, as would be the case if the boiler was being syphoned, the atmospheric pressure from without would open the valve, and by admitting air break the syphon.

Where there is no vacuum valve, what should be done?

A small hole should be drilled through the cold water pipe within the boiler, near the top.

What is an expansion pipe and its use?

In plumbing, it is a pipe taken from the highest point on the circulation and led above the source of supply, with its end over the tank, or above the roof. Its object is to relieve the boiler from any undue pressure that may arise.

Tank Supply System For Residence, With Circulation And Keyboard.

Why does a boiler collapse?

By letting cold water suddenly into a hot boiler, a sudden contraction of the water takes place, leaving a partial vacuum, and with the resistance within removed, the, pressure of the atmosphere from without crushes in the sides.

What is the advantage of a circulating system on the hot water?

By a continuous circulation the water in passing the fixtures is hot. Otherwise the cold water would have to be drawn out of the pipes whenever a faucet was opened, before hot water could be secured.

At what intervals should half-inch pipes be clipped up where there is no other support?

Once in eighteen to twenty-four inches.

Name different ways of securing a water supply in the country.

By gravitation, syphonage, hydraulic ram, windmill, steam pump, and house pump.

For what reason is compression work preferable to self-closing or Fuller work?

By the slow closing of compression work there is less danger of water hammer than in the quick closing of self-closing and Fuller work.

 

 

 

Hot-Water Supply

In connection with the supply work shown in Plate 51 there is also shown a system of hot-water supply, in which the kitchen-range boiler is heated both by the kitchen range and by a coil in the furnace. This is a very common practice not only in country work, but in the city also. Very often a small bath-room radiator may be heated from the hot-water supply.

The hot-water supply system is represented by the single heavy lines. There are several methods of heating a range boiler from the kitchen range and another heating source below it, and the method shown is probably the most satisfactory. It will be noted that in this method the course of the circulation of hot water is continuous, the hot water from the furnace passing through the range water-front, thence to the boiler and to the fixtures, and, when it has cooled, returning to the furnace coil. Two lines of circulation are shown, each being brought together on the return.

The use of circulating pipes, if properly installed, insures a constant supply of hot water close to the fixtures supplied, and naturally obviates the necessity of drawing off a long line of cold water before the water will run hot, as must be done in work unprovided with circulation.

This saving in the use of water is a matter of importance wherever water is metered or limited in amount.

Whenever the house supply is from an attic tank the hot-water supply must be under tank pressure, in the use of which system an expansion pipe is necessary.

Traps

A trap is a device or fitting used to allow the free passage through it of liquids and solids, and still prevent the passage of air or gas in either direction. There are two kinds of traps used on plumbing fixtures known as syphon traps and anti-syphon traps. The simplest trap is the syphon trap - a horizontal pipe bent as shown in

 

Fig.  This forms a pocket which will retain enough liquid to prevent air or gas from passing. The dip or loop is called the seal, and should never be less than one and one-half inches. This type of trap is what is known as a running-trap. This is not a good trap to use, and it is only capable of withstanding a very low back pressure.

The trap most generally used is what is known as the S trap, as shown in Fig 15. When this trap is subjected to a back-pressure, the water backs up into the vertical pipe, and naturally will withstand a greater pressure than the running-trap type - about twice as much.

Fig.

The trap shown in Fig 16 is what is known as a P trap, and in Fig 17 as three-quarter S trap, and has the same resisting power as the S trap.

A trap may lose its seal either by evaporation, self-syphonage or by suction. There is no danger of a trap losing its seal in an occupied house from evaporation, as it would take a number of week's time, under ordinary conditions, to evaporate enough water to destroy the seal.

Fig. 16.

Fig. 17.

A trap can be syphoned when connected to an unvented stack, and then only when the waste pipe from the trap to the stack extends below the dip, so as to form the long leg of the syphon as in Fig. 18.

Fig

When two fixtures are installed one above the other, with nnvented traps and empty into one stack, the lower trap can be syphoned by aspiration. The water emptying into the stack at the higher point in passing to the trap inlet of the lower fixture, creates a partial vacuum which sucks the water out of the trap at the lower point. To prevent this, what is known as back-venting is resorted to, back-venting not only protects the trap against syphonage, but relieves the seal from back-pressure, by equalizing the pressure on both sides of the seal. All revent pipes must be connected to vent pipes at such a point that the vent opening will be above the level of the water in the trap.

In Fig. 19 two basins are shown connected to soil pipe with S traps and back - vented into the air-vent pipe, both connecting into the attic into an increaser, which projects through the roof. This drawing is given to illustrate the proper back-venting to prevent syphonage of basin traps, and when it is necessary to run separate stacks for wash basins, such as are sometimes installed in bedrooms, the main waste stack must be two inches in diameter and the vent pipe one and one-half inches, either cast iron or galvanized wrought iron.

Non-syphon traps are those in which the seal cannot be broken under any reasonable conditions. Some water can be syphoned from the best of non-syphon traps made, but not enough to destroy their seal. The commonest non-syphoning trap is known as a drum trap, which is four inches in diameter and ten inches deep. Sufficient water always remains in this trap to maintain its seal, even when subjected to the severest of tests.

Fig. 19.

Fig. 20 shows a trap, which is the type generally used to trap the bathtub. This trap is provided with a brass trap-screw top for clean-out purposes, made gas and water tight against a rubber gasket. A trap of this kind would not be suitable for a lavatory, its principal fault being that owing to the enlarged body they are not self-cleaning, affording a lodging place for the depositing of sediment.

Fig. 20.

The non-syphon trap to be used is one in which the action of the water is rotary, as it thoroughly scours the trap and keeps it clean, such as is shown in Fig. 21. This trap depends upon an inner partition to effect this rotary movement, and is so constructed that its seal cannot be broken by syphonic action and is permitted by health and sanitary departments, where it is impossible to run a separate vent pipe to the roof.

Fig. 21.

Fig. 23.

One of the oldest traps is the Cudell trap, as shown in Fig. 22. The rubber ball being of slightly greater specific gravity than water rests on the seat and forms a seal when the water is not flowing through the trap. This ball prevents the seal of the trap being forced by back-pressure, and acts as a check against back flow of sewerage should drain stop up, and provides a seal if water is evaporated.

Fig. 23 shows the old Bower trap. The water seal is maintained by the inlet leg, extending down into the body below the outlet. The bottom of this trap is glass, brass or lead, whichever is desired, and can be unscrewed from trap and thoroughly cleaned.

Fig. 22.

 

Water Closets In General

The most important and useful plumbing fixture in a house is the water closet.

Water closets should be in all houses that make any pretentions towards convenience. That they are a vast improvement over the old-fashioned, offensive privy vault in the back yard, everybody will acknowledge. But it is equally true that, unless of a good pattern, properly fitted up, properly used, carefully watched and frequently cleansed, they may become not only the sources of foul smell but also the cause of disease.

Leaving aside the question of the pollution of the soil and of well waters, of which the privy vault must sooner or later be the cause, it is in itself a nuisance and an abomination. In cold weather and during rain storms persons are liable not to use it when they ought to, and trouble of the digestive organs is sure to follow, as every physician knows. This is especially the case with females and with delicate children. Sick persons and invalids may suffer severely from exposure to the weather. Add to this the often unbearable stench emanating in hot weather from such vaults, and it will be readily seen how superior in point of convenience, health and cleanliness an indoor water closet is.

There are other improved devices for receiving faecal matters, such as earth closets, ash closets, tubs or pails, which are far preferable to privies, and should be recommended wherever water is scarce; but these do not properly belong to my subject, which refers only to the "water carriage" system.

There is an endless list of water closets, and each year increases the number of newly invented and patented articles. It is, of course, impossible, nor is it even desirable, that my paper should give a complete description of all of them. I shall limit myself to describing the chief features of the various types of closets, mentioning a few examples of each type.

After reviewing the different patterns of water closets in use we shall speak of the general arrangement of the water closet apartment with respect to light and air.

The essential points to be considered in examining water closets are: the shape of the bowl or vessel receiving faecal matter; the apparatus for discharging the contents of the bowl; the manner of trapping the water closet; the manner of flushing the bowl and the trap; and the ventilation of the water closet.

The less surface a water closet has exposed to fouling, the cleaner and better will it be. All foul discharges should pass into water as quickly as possible. Thus the fouling of the sides of the vessel will be efficiently prevented and the water will have a tendency to deodorize the excrements. All water closets holding a large body of water in the bowl (valve and plunger closets, wash-out closets and latrines) have this advantage. In other closets, where the body of water is in the trap (hoppers), this latter should be as near as possible to the bowl (short hoppers are preferable on this account), and the rear side of the vessel should be designed nearly vertical and straight to prevent foul matter from soiling the bowl before passing into water.

A further requirement is durability and simplicity of the working apparatus The less moving parts a water closet has the better will it be. We must have regard to the rough usage to which such fixtures are sometimes subjected, especially in public places. Complicated or delicate mechanisms frequently get out of order, or fail to work properly under children's or servants' hands. Nobody can deny that, so far as this point is concerned, hopper and wash-out closets are vastly superior to pan, valve and plunger closets.

A water closet should have a copious supply of water completely to wash at each use the bowl and trap as well as all surfaces coming in contact with foul matter. I do not, however, wish to be understood as favoring reckless waste, for it is well known that allowing the water to run continuously through a water closet cannot be regarded as flushing. Two or three gallons properly applied at each use will cleanse a water closet more thoroughly than an uninterrupted trickling flow of water. In order to be efficient the flushing water should come down "in a sudden dash" To make the flush effective the supply pipe from cistern to bowl should be of large diameter, never less than one inch, and increasing up to 1 1/2 inches as the head (or height of bottom of cistern over the bowl) diminishes. The force of the flush largely depends upon the shape of the bowl and upon the head of water available in each With closet bowls, circular in shape, a flush introduced in the direction of the tangent will whirl around its circumference, losing its force without effecting much cleansing. An oval bowl provided with a fan flush is a vast improvement. The best bowls are those provided around the upper edge with a proper "flushing rim," into which the water from the supply pipe enters simultaneously at all sides, and is directed to rush vertically downward, thoroughly washing the sides of the closet and retaining sufficient force to expel the foul contents of the water closet trap.

The mode of flushing a water closet from the main supply pipe of the house is decidedly objectionable, especially with closets located in upper stories of city houses. If water is drawn from a faucet in the basement the pressure is often reduced so much as to create a slight vacuum in the upper part of the pipe. If the valve of a water closet happens to be opened at such times, air, if not foul matter, rushes into the pipe from the bowl. Thus the purity of the drinking water is endangered, while the closet remains without a flush. This risk can be partially avoided by the use of a check valve on the supply pipe to the closet valve. Such check valves, however, are not reliable and often fail to shut properly.

Closets, holding water in the bowl (pan, valve, plunger and washout closets) require an "after flush" to refill the bowl, and the cisterns should be provided for such purpose, with a service box, holding a certain quantity of water. The outlet from the cistern to the service-box must be closed by a large sized valve in order to secure a quick filling of the service-box.

Cisterns, arranged with a view to prevent the waste of water, are desirable wherever the water supply is apt to become scanty during the hottest and coldest months of the year. They have, in this case, three compartments, a large tank, supplied by a ball-cock, a measuring cistern, holding the quantity of water fixed for each flush, and a service-box for the after flush.

Water waste preventers for hoppers, however, require only two compartments, the receiving tank and the measuring cistern.

Water closet cisterns are operated either by the common pull-up arrangement, a handle being connected to one end of a lever, the fulcrum of which is firmly secured to the floor, while the other end of the lever is connected by a brass safety chain to the lever operating the cistern valve. Such an arrangement is common for pan, valve and plunger closets. Or else the lever and valve is operated directly by a chain, with tassel or ebony handle, which arrangement seems best adapted to hoppers and washout closets (and slop sinks).

Tvpes C

A Pan closet. B Valve closet. C Pit D Lo

C is a plunger closet with improved flushing rim bowl, supplied with water from a cistern, the outlet of the closet being on one side and closed by a plunger working in a chamber and to be operated by knob and pull. The trap is above the floor and provided with a hub to attach a vent pipe.

While these three closets are operated by more or less complicated machinery, the three following types are free from any movable parts.

D is a long flushing rim hopper having an S-trap under the floor.

E is a short flushing rim hopper with S-trap above the floor.

F is a washout closet, holding water in the basin, which also serves as a trap.

Fig. 5 shows the general characteristics of a trough closet (latrine).

Fig.8

 

Fig. 200. "S"-Pattern Trap..

Fig. 201. A Bag Trap..

In buildings where the plumbing may be left unused for weeks from time to time, as is likely in rented houses, deep-seal traps, or those with mechanical seals also, should be used. This point is not so important in detached houses or those rented to one family only at a time, since, when a family moves out, there is no one to suffer. But in flat buildings, where some of the flats may be vacant for a time sufficient for an ordinary seal to be broken while other families are living in the house, deep-seal traps are more essential.

Fig. 201 shows what is termed a bag trap, made to bring the inlet and outlet in the same vertical line. These traps are inter-clvangeable with any others with straight-line outlet - for instance, as shown in Fig. 204.

An open-wall trap partly cast and partly tubing, generally made of brass, is shown in Fig. 202, the vent connection to wall being at A. This form of trap generally has a swivel-joint at B, which is below the water line, so that the body may be swiveled to meet roughing-in openings in any direction within two diameters of the line of fixture outlet. The bag form shown is most convenient for D-shape or standing waste bowls which present the outlet comparatively near the wall. The regular "S" of this type suits bowls with center outlet, and will reach a wider range of variation in roughing-in.

Fig. 202. Open-Wall Trap. Partly Cast..

Fig. 203 shows a common lead drum or pot trap, most convenient to the plumber. It is furnished without openings, and the plumber makes bends, and wipes-in his inlet and outlet at points in the circumference most convenient to reach the fixture opening. A is the screw-top clean-out; and B, the wrench-face for turning it. The trap is furnished, when desired, with nickel-plated brass flanged cover, as shown at C, to screw on at the floor-level. F is ordinarily the outlet, the inlet being wiped-in near the bottom to give it the water-lock. This is not proper, however, as it puts the sewer air against the clean-out cover, which might leak gases into the building without betraying any evidence of its defectiveness by water leakage. To be strictly correct, F should be the inlet; and the outlet, in the shape of an offset, or that of an inverted P-trap without the trap-screw, should be wiped-in near the bottom in a way to retain the proper seal and thus bring the sewer air against the water-seal instead of the clean-out cover.

Traps that retain their seals by means of interior weirs are of doubtful character, even at their best; none but well-tested cast-brass traps of such a pattern should ever be installed. Fig. 204 is a section of a flask or Atlas trap, with vent, usually made of cast brass and depending upon two interior weirs to form the seal, one retaining the water, and the other dipping into the water to prevent sewer air from getting into the house through the fixture. If the water weir of such a trap becomes defective, there is no evidence except odors by which the occupants may discover it. If the dipping weir is defective the value of the water seal is nil. In either case the trap is no barrier to the admission of drain air to the house.

Fig. 203. Common Lead Drum or Pot Trap..

Fig. 204. Section of Flask or Atlas Trap with Two Interior Weirs..

Fig. 205 illustrates a form of trap suitable for use with baths. It has a submerged inlet connection which is expanded so that the flow enters the trap at a dipping angle which produces a swirl with cleansing effect. The extension collar A is made so that the screw-cover B forms the gasket joint below the water-level. The method of providing the outlet in this trap makes it open to the same objection raised in connection with Fig. 203. This form, however, has the merit of being accessible for inspection without disturbing its service, which is impossible with the flask pattern shown in Fig. 204.

Various Types Of W.C.'s, And Water-Waste Preventers. Part 3

Urinals are of two types, the lipped basin and the circular back. The lipped basin (Fig. 209) is trapped in itself, but the circular-backed (Fig. 210) discharges into a channel with a perforated grating on top, which is easily cleansed. This channel is trapped at the end with a gulley, and the trap ventilated before its connection to the drain.

Fig. 208.

Fig. 209.

Fig. 210.

Sinks And Their Wastes

Scullery sinks are best in glazed stoneware, as York stone absorbs the grease.

They are usually about 3 feet by 2 feet, and about 2 feet 6 inches from the floor to the top edge (see Fig. 211). They may be supported on half-brick walls rendered in Portland cement, or on cast-iron brackets, or on glazed pedestals. The sink should have a good fall to the outlet, which should be arranged in the corner on the side next the outer wall. The outlet should be fitted with a 3 1/2-inch bell-mouthed cobweb grating, and the waste trapped with a trap at least 2 inches internal diameter, with inspection screw cap as shown in Fig. 212.

Fig. 211.

Fig. 212.

Housemaid's Sink

This is usually in connection with the slop-sink, but it is more usual to empty the slops down the water-closet. Fig. 213 shows a Doulton's combined wash-up and slop-sink. The basin and trap are in earthenware, and there are valves for hot and cold water. The wooden grating on the wash-up side is to prevent crockery from being broken by contact with the stoneware. The trap and waste should be ventilated and connected to a soil pipe outside.

Butler's sinks are usually 15 inches deep, in lead, with 10-lb. bottom, and 7-lb. sides; the joints at the angles and bottom being made by means of welts.

Where a large amount of hot water is used it is found that the expansion and contraction crack the joint on the lead trap. To prevent this an expansion joint, as shown by Fig. 215, is used. The expansion and contraction are taken up by a solid rubber ring passing round the outside of the upper pipe, and allowing it to move up and down. Another method is to use cast - brass traps; but, although they are not liable to so great expansion and contraction, being rough inside from the core sand, they catch and retain the grease, and are therefore not so cleanly as the lead traps.

Fig. 216.

Taps And Fittings

The regulations of Water Companies cause these fittings to vary in different localities, so that what may be legally used in one part of the country is forbidden in another.

Fig. 216 shows a section through Lord Kelvin's bib tap. This avoids the use of washers, and the turning of the tap grinds the valve on its seating.

Fig. 217.

Fig. 217 shows a stop cock for connection to a lead pipe. It will be noticed that the joint is made by a brass-screwed collar, and not by the wiped joint as in ordinary practice.

Fig. 218 shows a quick-turn full-way cock which can be used as a stop cock.

A quarter-turn bib valve is shown by Fig. 219.

Where the pressure is low, a clear-way wheel valve may be used, as shown by Fig. 220. This valve does not diminish the force of the flow.

If the water supply is limited, a spring valve is used for lavatory basins, as shown by Fig. 221. It is actuated by pressing the knob at the top, which springs back, shutting off the water when the pressure is released.

Fig. 218.

Fig. 219.

Fig. 220.

To prevent birds, dirt, etc., entering overflows, and the ingress of cold air in winter, a flap valve is used, as shown by Fig. 222.

In storage cisterns and water-waste preventers, a full-way ball valve, as shown on Fig. 223, is used. It permits the water free egress, and automatically closes when the tank is full.

Fig. 221.

Where quick closing taps, such as the spring valve, are used, an air chamber should always be fixed, to stop the noise made by the sudden closing of the tap. This noise is known by the name of "water-hammer," and is caused by suddenly stopping the flow of water shows an air chamber on an ascending pipe, Fig. 225 on a descending pipe, and Fig. 226 when the tap is on a rising main.

Fig. 224.

(taking place through the whole of the pipes) when a tap is closed. With a screw-down tap, however, the water is shut off gradually, and no appreciable concussion occurs. The use of an air chamber is to act as a buffer when sudden pressure is put on. Fig. 224

Drainage

When the main line of drains has been laid the trenches can be continued in a similar manner to the gulleys or soil pipes. Right-angled junctions should never be permitted, but special pipes with easy bends should be used (see Fig. 185). Connections should be made at the sides and not top of the pipes.

Fig. 186 shows a method of carrying stoneware drains on marshy or silty ground. 12 by 6-inch piles are driven about 6 feet apart and two 12 by 4-inch runners secured to each side of these piles with coach screws. The bottom of the trench is then made firm by clay puddling, the concrete foundations put in, and the pipes laid in the usual way.

Fig. 184.

Fig. 185.

Cast-Iron Pipes

When it is found necessary to carry a line of mains through a house, cast-iron pipes should be used and completely covered with concrete. These are made in 9-feet lengths, and weigh as follows:-

3	inches	1/4-in.	metal,	no	lbs.	per	9-ft.	length.
4	"	3/8	"	160		"		"
5	"	3/8	"	190		"		"
6	"	3/8	"	230		"		"

Rust joints are sometimes used for iron pipes, but caulked joints are preferable, as the expansion of the rust cement when setting has a tendency to burst and crack the sockets of the pipes. The usual way is to make the joints with lead wire or molten lead and caulk them afterwards. Turned and bored pipes have been used, and it has been found that they readily adjust themselves to slight settlements.

The inside surfaces of pipes should either be coated with Dr. Angus Smith's solution, or glass enamel. The former is more generally used, the latter being costly and liable to chip and crack.

Fig. 186.

Fig. 187.

All junctions and bends should be arranged with cast-iron access pipes fitted with air-tight covers secured with brass screws.

Intercepting And Inspection Chambers

Fig. 187 shows an Intercepting Chamber. These should be built in cement, on a concrete bed at least 9 inches thick, and finished on top with a double or single seal cast-iron manhole cover. The concrete foundation having been put in, the disconnecting trap is placed in position and set perfectly level. There are many varieties of intercepting traps in the market, but a satisfactory one should have a 3-inch weir action and 1 1/2-inch water seal and sweeping arm.

All half-channel pipes and bends should have 1-inch fall in their length in addition to the general gradient, to compensate for the loss of head due to friction.

Should the sewer be at a great depth, ramps may be used to save the expense of laying deep drains. These have a short arm with stopper fixed in same carried through the wall of manhole for rodding the drains.

Another form of ramp is that shown by dotted lines, the main pipe being continued full bore direct into the chamber, and a galvanised cast-iron flap valve fixed at the chamber end, to enable the sewage to flow into the chamber should the ramp become blocked.

The minimum internal dimensions of chambers should be 3 feet 0 inches by 2 feet 3 inches. In deep drains, however, they may be as large as 4 feet 1 1/2 inch by 2 feet 7 1/2 inches, and be gathered over at a height of 5 feet 6 inches above invert of drain, and continued to ground level with a shaft 1 foot 10 1/2 inches by 1 foot 10 1/2 inches inside dimensions.

Chambers over 4 feet deep should have step irons 1 foot 6 inches apart.

Where the distance between two inspection chambers exceeds 100 feet, sweeping eyes may be constructed, as shown by Fig. 188. These should be finished with a stopper bedded in soft soap and covered by a slab of York stone and a small hinged cast-iron cover. Inspection chambers are similar in construction to intercepting chambers, but the fresh-air inlet and intercepter are omitted.

Fig. 189

.

Elevators:-

Hydraulic Elevators And Motors

Hydraulic Elevators And Motors. Part 2

Whether this plan is practicable or not must be left to elevator manufacturers, but it seems to me that with the Hale-Otis elevator for instance (which is conceded to be one of the best) it could easily be accomplished. Certainly some such arrangement would effect a great saving of water, and perhaps bring water bills to a point that this class of consumers could afford to pay.

Hydraulic elevators where the water is used over and over again, by being pumped from the discharge to elevated tanks, cut little or no figure in connection with a city's water supply. When fuel, first cost, attendance of an engineer, and the poor economy of the class of pumps usually employed to perform this work are considered, the cost of operating such elevators is greatly in excess of what it would be if power were supplied direct from water mains, at any reasonable rate. The following remarks will then relate almost exclusively to that class of hydraulic elevators supplied with power directly from the water mains.

The "water hammer" produced by the quick acting valves of elevators has always been objectionable, both in its effect at the pumping-house and upon water mains and connections. To obviate this, Engineer G. W. Pearson has suggested the use of very large air chambers on the elevator supply, and still smaller openings in the mains, his theory being that the air chambers would not only materially decrease the concussion or "water hammer," but that they would also act as accumulators of power (or water under pressure) to be drawn from at each trip of the elevator, and replaced when it was at rest. This plan I have never seen put to actual test, but believe it to be entirely practicable, and that we will have to ultimately adopt it.

All things considered, the plan of operating elevators from tanks in the top of buildings, supplied by a small pipe connected with the water-mains and arranged with a float valve to keep the tank filled, I believe to be the best manner of supply, except for the great additional cost of putting up such apparatus. By this arrangement the amount of water consumed is no less, in fact it would ordinarily be more than with a direct connection with the mains, but it has the advantage of taking the water in the least objectionable manner. Still, if this mode of supply were generally enforced, the large first cost, an additional expense of operating, would undoubtedly deter many from using elevators.