Chapter VIII: Part 8

Start the pump at about its maximum speed; place the key in the keyhole on the side of the governor and turn to the right until the speed of the pump has diminished slightly. Open the throttle valve wide, and the pump will be under full control of the governor. Should there be much dancing or fluctuation of the ball, remove the screw, _T_, insert a small screwdriver, and screw the adjusting screw in, at _K_, until the irregular motion ceases. After the governor has run a little while, it will be found that the oil in the glass gauge has dropped considerably. It should then be refilled, so that the glass will be about half full when the governor is at work. Under no circumstances should the gauge be full, as too much oil will prevent the ball from coming down and opening the valve when the steam pressure falls. As there is no glass pressure upon the glass gauge the governor may be filled while in motion by removing the plug on the top of the gauge.

_The Mason elevator pump pressure regulator._ This regulator, illustrated in Fig. 569, is designed for use in connection with the larger sizes of steam pumps operating hydraulic elevators. Its important feature is in operating on the slightest change of pressure opening to its fullest extent and closing the steam valve promptly and positively.

Referring to sectional view, Fig. 570, the operation of this valve is as follows: steam from the boiler enters the regulator at the inlet, indicated by the arrows and passes through into the pump, which continues in motion until the required water pressure is obtained in the system, and through a 1/4-inch pipe connected to, _A_, acts upon the diaphragm, _B_. This diaphragm is raised by the excess water pressure, and carries with it the weighted lever, _F_, opens the auxiliary valve, _D_, and admits the water pressure from the connection, _E_, to the top of the piston, at the same time opens the exhaust ports under the piston, and allows the water under the piston to escape into the drip pipe, thereby pushing the piston down, closes the steam valve and stops the pump.

As soon as the pressure in the system is slightly reduced, the lever, _F_, on account of this reduced pressure under the diaphragm, is forced down by the weight, carries with it the auxiliary valve, _D_, opens the exhaust to the top of the piston, and also admits water pressure under the piston, which is forced up and opens the steam valve, and starts the pump.

The speed controlling device of the style A governor shown in Fig. 571 is simple and can be so set as to prevent the pump from racing, regardless of the drop in water pressure. Surrounding the upper end of the valve stem is a coiled spring, which acts as a cushion for the valve and stem, and by the use of a spring, the stem can be quite small thus reducing the friction in the stuffing-box to a minimum. The tension of this spring is sufficient to firmly seat the valve, but if excessive pressure is exerted on the piston, which is often the case when two or more pumps are connected to the same mains, the spring will be compressed and will allow the sleeve to slide down on the stem, thus relieving the valve of the increased strain, which would be liable to injure it or buckle the stem.

The regulating hand wheel remains cool, and can be manipulated without injury to the hands. The regulation is very simple, and is quickly adjusted by simply turning the wheel to the right or left, to increase or decrease the pressure. No locking device is necessary, as the wheel will remain in any set position.

The cylinder will not become coated with lime, but will retain its smooth surface over which the piston travels, insuring free action, with no leakage around the piston. The drip is located at the extreme upper travel of the piston, so as to retain sufficient water in the cylinder to prevent any air from coming in contact with leather piston packing. This arrangement insures a tight piston as the leather packing will remain soft and pliable and at the same time the water serves as a lubricant for the interior of the cylinder.

The hand wheel can be placed in different positions and all that is necessary to make the change is to take out the bolts and move the regulating hand wheel to the desired position. By this arrangement the engineer can set the hand wheel regardless of the arrangement of the steam piping.

All sizes, including 1-1/2-inch and smaller, are made as shown in style B, Fig. 572, and are not provided with an automatic speed controlling device. This style is made especially for boiler feed pumps and for supply pumps for the street system of hot water heating. They are also fitted with a special valve for pumps working under very high steam and low water pressure.

The finished parts of these Carr steam pump governors, Figs. 571 and 572, are nickel plated.

The valves and seats in these governors and regulators are renewable, Fig. 573. The tools necessary to remove the seats are a wrench and a flat piece of iron wide enough to span the lugs on top of the upper seat. The upper seat is threaded and screwed into the upper opening in the valve chamber. The lower valve seat is fitted into the lower opening, a steam-tight fit, but is free to move sufficiently to compensate for the expansion of the valve.

The bridges, which unite the valve seats, contain about an equal quantity of metal, and are of equal length with the post that binds the valve discs, thus compensating for the expansion and contraction of the metal and insuring a perfectly tight valve, regardless of the temperature of the steam.

_The Holyoke Improved Speed Governor for water wheels_ is shown in Figs. 574 and 575. The following is a description of the two figures where the same letters are used to designate the parts appearing in both illustrations:

The pulley, A, is the receiving pulley, and is designed to run at 400 revolutions per minute, receiving its power from the water-wheel shaft, or countershaft belted from the same.

Contained in the pulley, A, are the two governing weights, BB, of which the centrifugal forces are overcome by the springs, CC. The varying motions of the governing weights, BB, are transmitted through racks and pinions in the hub of pulley, A, to levers, K and L, which operate the valve, N, admitting water under a light pressure to the cylinder, O. The water is admitted to the cylinder, O, through ports at either end, causing the piston to move forward or backward, governed by the movement of the governing weights, BB.

The pulley, A, is keyed to the main shaft, and at the opposite end is keyed a bevel pinion running in mesh with a bevel gear on either side, all of which are contained in the gear-case, P. These gears cause the clutch discs, D, to run in opposite directions. In each disc is a clutch, E, keyed to a shaft, transmitting power to the pinion, S, running in mesh with the spur gear, R, which is loose on the shaft, J, and transmits its power through the pin clutch, T, to gate shaft, J. The gate shaft, J, is connected by a pair of bevel gears to the shaft and hand wheel, Q.

The motion of the piston rod, I, caused by the movement of piston in cylinder, O, is carried by the lever, G, to the clutch shaft, F, by means of the pivoted nut at V. The clutch shaft, F, operates either clutch, E, corresponding to the movement of the governing weights, BB, caused by the variation in speed. From the clutch thus engaged, the power is carried by the clutch shaft, F, through the gears, S and R, and the pin clutch, T, to the gate shaft, J.

The makers of the machine here described, say: “In the year 1902
our attention was called to a new governor invented by _Nathaniel
Lombard_, and after finding by actual tests that this governor
possessed advantages over all others then in use, we were induced to
make arrangements for its manufacture and sale. Two years have been
spent in improving and perfecting this machine, hence the name ‘The
Improved Governor.’”

The governor is provided with a steadying device operated by the chain, H. The gate shaft, J, is designed to make four, six or eight turns to open the gate, four being the regular number.

The receiving pulley and governor gate shaft may revolve in either direction, as desired.

The receiving pulley is designed to run at 400 revolutions per minute, and is driven by a 4-inch double belt.

The governor gate shaft may be arranged to open the gates in four, six or eight turns, and may be extended on either or both sides of the governor to meet the necessary requirements.

The governor is capable of exerting a pressure ranging from 25,000 to 50,000 foot pounds on the governor gate shaft.

The advantages claimed for this improvement on _the Lombard governor_ are thus stated:

1. It requires only a light water pressure to handle the heaviest gates.

2. It is simple in construction. All parts are easy of access.

3. There are no pumps working under high pressure.

4. There are no dash pots to get out of adjustment, due to the change in temperature of oil, etc.

5. There is but one belt on this machine.

6. All parts which are constantly in motion are equipped with ring-oiling bearings.

Fig. 576 is an illustration of the mechanism necessary to raise and lower _the head gates_ which are used to admit and regulate, also to shut off the water supply from pond or lake _to the flume conveying it to the wheel_. In this case there are two head gates having racks upon the upright timbers connecting with the gates. Two shrouded pinions engage these racks, which are keyed upon a shaft having a large spur wheel at its end, as represented. A pinion upon a second shaft engages this spur wheel which in turn has also a spur wheel which engages a pinion upon the crank shaft having two cranks opposite one another. By means of these cranks with two to four men upon each crank the gates are operated very satisfactorily. These shafts and gears are mounted upon heavy cast iron brackets bolted to the floor. Altogether it forms a very massive piece of mechanism.

_The Utility combination pump governor_ is shown in the figure below. This mechanism may be bolted on any tank or receiver where the water level is to be automatically maintained. It consists of a closed pocket containing a float, A, which rises and falls with the water level inside the tank.

When the water rises above the desired level the float opens the throttle valve and starts the pump, and when it subsides the float falls and shuts off the steam.

CONDENSING
APPARATUS

CONDENSING APPARATUS.

_A condenser_ is an apparatus, separate from the cylinder, in which exhaust steam is condensed by the action of cold water; _condensation_ is the act or process of reducing, _by depression of temperature or increase of pressure_, etc., to another and denser form, as gas to the condition of a liquid or steam to water. There is an electrical device called “a condenser” which must not be confounded with the hydraulic apparatus of the same name; there is also an optical instrument designated by the same term, which belongs to still another division of practical science.

_A vacuum_ is defined very properly as an empty space; a space in which there is neither steam, water or air—the absolute absence of everything. The condenser is the apparatus by which, through the cooling of the steam by means of cold water, a vacuum is obtained.

_The steam after expelling the air from the condenser fills it with its own volume_ which is at atmospheric pressure nearly 1700 times that of the same weight of water.

Now when a vessel is filled with steam at atmospheric pressure, and this steam is cooled by external application of cold water, it will immediately give up its heat, which will pass off in the cooling water, and _the steam will again appear in a liquid state_, occupying only 1/1700 part of its original volume.

But if the vessel be perfectly tight and none of the outside air can enter, the space in the vessel not occupied by the water contains nothing, as before stated. The air exerting a pressure of nearly 15 pounds to the square inch of the surface of the vessel tries to collapse it; now if we take a cylinder fitted with a piston and connect its closed end to this vessel by means of a pipe, the atmospheric pressure will push this piston down. The old low pressure engines were operated almost entirely upon this principle, the steam only served to push the piston up and exhaust the air from the cylinder.

In Fig. 578 is exhibited the effect of jets of water from a spray nozzle meeting a jet of steam; the latter instead of filling the space with steam is returned to its original condition of water and the space as shown becomes a vacuum.

Briefly stated condensation and the production of a vacuum may be used to advantage in the following ways:

1. By increasing the power without increasing the fuel consumption.

2. By saving fuel without reducing the output of power.

3. By saving the boiler feed water required in proportion to the saving of fuel.

4. By furnishing boiler feed water free from lime and other scaling impurities.

5. By preventing the noise of the escaping exhaust steam.

6. By permitting the boiler pressure to be lowered ten to twenty pounds without reducing the power or the economy of the engine.

The discovery of the advantages arising from the condensation of steam by _direct contact with water_ was accidental.

In the earliest construction of steam-engines the desired vacuum was produced by the circulation of water through a jacket around the cylinder. This was a slow and tedious process, the engine making only seven or eight strokes per minute. “An accidental unusual circumstance pointed out the remedy, and greatly increased the effect. As the engine was at work, the attendants were one day surprised to see it make several strokes much quicker than usual; and upon searching for the cause, they found, says Desaguliers, ‘a hole through the piston which let the cold water (kept upon the piston to prevent the entrance of air at the packing) into the space underneath.’ The water falling through the steam condensed it almost instantaneously, and produced a vacuum with far less water than when applied to the exterior of the cylinder. This led Newcomen to remove the outer cylinder, _and to insert the lower end of the water pipe into the bottom of the cylinder_, so that on opening a cock a jet of cold water was projected through the vapor. This beautiful device is the origin of the injection pipe with a spray nozzle still used in low-pressure engines.”

The apparatus described above is called the _jet-condenser_ and is in use up to the present day in various forms. In the Fig. 577, page 298, the jet is shown at C. It will be understood that steam enters through the cock D and comes in contact with a spray of cold water at the bottom, where it is condensed and passes into the air pump through which it is discharged.

By this diagram, Fig. 577, may be understood in a simple yet accurate manner _the course of steam from the time it leaves the boiler until it is discharged from the condenser_.

Referring to the upper section of the plate, a sectional view of a steam cylinder, jet condenser, air pump and exhaust piping is shown. The high pressure steam “aa” is represented by dark shading, and the low pressure or expanded steam “bb” by lighter shading.

The steam enters the side “aa,” is cut off, and expansion takes place moving the piston in the direction of the arrow to the end of the stroke. The exhaust valve now opens and the piston starts to return. The low pressure steam instead of passing direct to the atmosphere, as is the case of a high pressure engine, flows into a chamber “C,” and is brought in contact with a spray of cold water. The heat being absorbed by the water, the steam is condensed and reduced in volume, thus forming a vacuum. It is, however, necessary to remove the water formed by the condensed steam together with the water admitted to condense the steam, also a small amount of air and vapor. For this purpose, a pump is required, which is called the air pump.

Condensers are classified into _surface condensers and jet condensers_, both again being divided into direct connected and indirect connected condensers.

The surface condenser (see Fig. 579) is mainly used in marine practice because it gives a better vacuum, and keeps the condensed steam separate from the cooling water; it consists of a vessel, of varied shapes, having a number of brass tubes passing from head to head. The ends of this vessel are closed by double heads, the tubes are expanded into the inner one on one end, while their other ends pass through stuffing-boxes in the other inner head.

The “admiralty” or rectangular surface condenser is represented in Fig. 579. This form occupies less floor space than the round shell, and is preferred upon steam yachts and small vessels.

Steam is condensed on its introduction at the top of the apparatus where it comes in contact with the cool surfaces of the tubes. Through these water is circulated by a centrifugal pump driven usually by a separate engine.

_The water of condensation_ leaves the condenser at the bottom and is drawn off by the vacuum pump. _The water from the circulating pump_ enters at the bottom right-hand end; following the direction indicated by the arrows, it flows through the lower half of the tubes towards the left whence it returns through the upper half of the tubes towards the right and escapes overboard through the water outlet pipe.

It will be observed that the coolest water encounters the lowest temperature of steam at the bottom, hence the best results are reached. There is also a baffle plate just above the upper row of tubes to compel a uniform distribution of exhaust steam among the tubes, as shown in the engraving.

These tubes are usually small—1/2″ outside diameter—of brass and coated with tin inside and outside to prevent galvanic action which is liable to attack the brass tubes and cause them to corrode.

Fig. 581 shows an end view of the right-hand head of the surface condenser here described.

A single tube is shown in detail in Fig. 580. One end of the tube is drawn sufficiently thick to chase upon it deep screw threads, while a slot facilitates its removal by a screw-driving tool. The other end is packed and held in place by a screw gland, which is also provided with a slot. In this way the tube is firmly held in one head, and, though tightly fitted in the other, is free to move longitudinally under the influence of expansion or contraction, due to the varying heat.

In some cases engineers prefer the ordinary arrangement of screw glands at both ends of the tubes, with the usual wick packing.

The mechanism illustrated in Figs. 582 and 583 shows _a combined condenser and feed-water heater_. A compact and efficient method of heating the feed-water from the hot well is of great importance; this is the case in cold weather when the circulating water is at a low temperature.

_The Volz apparatus_ is a combined condenser and feed-water heater; the shell or exhaust steam chamber contains a set of tubes, through which the feed-water passes, while the lower part contains the condensing tubes, both parts being in proper communication with their respective water chambers. The heater tubes being located immediately adjacent to the exhaust inlet, are exposed to the hottest steam, and the feed-water becomes nearly as high temperature as that of the vacuum. Pages 304 and 305 show the sectional and outside views. The enclosing shell containing the combined heater and condenser is a well ribbed cylindrical iron casting; free and independent access is provided to either set of tubes by removing corresponding heads.

The illustration, Fig. 584, is a longitudinal section of one side of the condenser pump, and also a section of the condenser cone, spray pipe, exhaust elbow and injection elbow. “A” is the exhaust to which is connected the pipe that conducts to the apparatus the steam or vapor that is to be condensed. The injection water is conveyed by a pipe attached to the injection opening at “B.” “C” is the spray pipe, and has, at its lower extremity, a number of vertical slits through which the injection water passes and spreads out into thin sheets.

The spray cone “D” scatters the water passing over it, and thus ensures a rapid intermixture with the steam. This spray cone is adjustable by means of a stem passing through a stuffing-box at the top of the condenser, and is operated by the handle “E.” The cone should be left far enough down to pass the quantity of water needed for condensation.

_All regulation of the injection water must be done by an injection valve placed in the injection pipe at a convenient point._

NOTE.—The surface condensers, Figs. 579-581, are made by the Wheeler
Condenser and Engineering Co., New York, as are also the Volz
combined surface condenser and feed water heater, shown in Figs. 582
and 583.

_The operation of this condensing apparatus is as follows_: steam being admitted to the cylinders “K,” so as to set the pump in motion, a vacuum is formed in the condenser, the engine cylinder, the connecting exhaust pipe, and the injection pipe. This causes the injection water to enter through the injection pipe attached at “B” and spray pipe “C” into the condenser cone “F.” The main engine being started, the exhaust steam enters through the exhaust pipe at “A,” and, coming in contact with the cold water, is rapidly condensed. The velocity of the steam is communicated to the water, and the whole passes through the cone “F” into the pump “G” at a high velocity, carrying with it, in a comingled condition the air or uncondensable vapor which enters the condenser with the steam. The mingled air and water is discharged by the pump through the valves and pipe at “J” before sufficient time or space has been allowed for separation to occur.

_The exhaust steam induction condenser_ is based upon the same principle heretofore explained under the section relating to injectors. See Fig. 585.

The exhaust steam enters through the nozzle, A. The injection water surrounds this nozzle and issues downward through the annular space between the nozzle and the main casting. The steam meeting the water is condensed, and by virtue of its weight and of the momentum which it has acquired in flowing into the vacuum the resulting water continues downward, its velocity being further increased, and the column solidified by the contraction of the nozzle shown. The air is in this way carried along with the water and it is impossible for it to get back against the rapidly flowing steam in the contracted neck. The condenser will lift its own water twenty feet or so. When water can be had under sufficient head to thus feed itself into the system, and the hot-well can at the same time be so situated as to drain itself, it makes a remarkably simple and efficient arrangement. In case the elevation is so great that a pump has to be used to force the injection, the pump has to do less work than the ordinary air pump, and its exhaust can be used to heat the feed water.

_The Bulkley “Injector” condenser_ is shown in Fig. 586, arranged so that the condensing water is supplied by a pump. The condenser is connected to a vertical exhaust pipe from the engine, at a height of about 34 feet above the level of the “hot-well.” An air-tight discharge pipe extends from the condenser nearly to the bottom of the “hot-well,” as shown in the engraving.

The condenser is supplied by a pump as shown, or from a tank, or from a natural “head” of water; the action is continuous, the water being delivered into the “hot-well” below. The area of the contracted “neck” of the condenser is greater than that of the annular water inlet described above, and the height of the water column overcomes the pressure of the atmosphere without.

The supply pump delivers cool water only, and is therefore but one-third of the size of the air-pump. The pressure of the atmosphere elevates the water about 26 feet to the condenser.

The accompanying diagrams, Figs. 587 and 588, are worthy of study. They represent _a condenser plant_ designed by the Schutte & Koerting Co., Philadelphia, and placed on steam-vessels plying on fresh water. In these drawings the parts are designed by descriptive lettering instead the ordinary way of reference figures; this adds to the convenience of the student in considering this novel application of the condenser-injector, the action of which is described in the following paragraphs.

For steamers plying on fresh water lakes, bays and rivers it is unnecessary to go to the expense of installing surface condensers such as are used in salt water; keel condensers, however, are used in both cases.

_The keel condenser_ consists of two copper or brass pipes running parallel and close to the keel, one on each side united by a return bend at the stern post. The forward ends are connected, one to the exhaust pipe of the engine while the other end is attached to the suction of the air pump.

In other cases both forward ends are attached to the exhaust pipe of the steam engine while the water of condensation is drawn through a smaller pipe connected with the return bend at the stern post which is the lowest part of the keel condenser.

Fig. 587 is much used for vessels running in fresh water. The illustration is a two-thirds midship section of a vessel with pipe connections to the bilge—bottom injection—side injection into the centrifugal pump, thence upward through suction pipe into the ejector condenser where it meets and condenses the exhaust steam from the engine and so on through the discharge pipe overboard. The plan of piping with valves, drain pipes and heater are shown in Fig. 588.

In case of the failure of any of the details of this mechanism to perform their respective functions a free exhaust valve and pipe is provided which may be brought instantly into use. The discharge pipe has a “kink” in it to form a water seal, as represented with a plug underneath to drain in case of frost, or in laying up the vessel in winter. A pipe leads from globe valve (under discharge elbow) to feed pump for hot water.

_Condensing Surface Required._ In the early days of the surface condenser it was thought necessary to provide a cooling surface in the condenser equal to the heating surface in the boilers, the idea being that it would take as much surface to transfer the heat from a pound of steam to the cooling water and condense the steam as it would to transfer the heat from the hot gases to the water in the boiler and convert it into steam. The difference in temperature, too, between the hot gases and the water in the boiler is considerably greater than that between the steam in the condenser and the cooling water.

NOTE.—The following list gives the numbers with the corresponding
names of the parts of _the surface condenser_, shown in the above
outline sketch: 1, condenser shell; 2, outside heads; 3, exhaust
inlet; 4, exhaust outlet; 5, water inlet; 6, water outlet; 7,
peep holes; 8, tube heads; 9, partition; 10, rib; 11, tubes; 12,
stuffing-boxes.

NOTE.—The numbers and names of parts in the above figure,
representing in outline a _jet condenser_, are as follows: 1,
condenser body; 2, exhaust inlet; 3, discharge; 4, injection valve;
5, spray pipe; 6, spraying device.

_Steam, however, gives up its heat to a relatively cool surface much more readily than do the hot furnace gases_, and the positively circulated cooling water takes up that heat and keeps the temperature of the surface down, while in a boiler the absorption depends in a great measure upon the ability of the water by natural circulation to get into contact with the surface and take up the heat by evaporization. It has been found, therefore, that a much smaller surface will suffice in a condenser than in the boilers which it serves.

The Wheeler Condenser and Engineering Company, who make a specialty of surface condensers, say that one square foot of cooling surface is usually allowed to each 10 pounds of steam to be condensed per hour, with the condensing water at a normal temperature not exceeding 75°. This figure seems to be generally used for average conditions. Special cases require special treatment.

For service in the tropics the cooling surface should be at least ten per cent. greater than this estimate. Where there is an abundance of circulating water the surface may be much less, as with a keel condenser, where 50 pounds of steam is sometimes condensed per hour per square foot of surface; or a water works engine, where all the water pumped is discharged through the condenser and not appreciably raised in temperature, probably condensing 20 to 40 pounds of steam per hour per square foot of surface.

Under the division of this volume devoted to “air and vacuum pumps,” much information has been given relating to the principles of the condensation of steam and also some illustrations of working machines. Still it may be well to say this, in addition, that—

All questions in regard to a vacuum become plain when we consider that the atmosphere itself exerts a pressure of nearly 15 pounds, and measure everything from an absolute zero, 15 pounds below the atmospheric pressure. We live at the bottom of an ocean of air. The winds are its currents; we can heat it, cool it, breathe and handle it, weigh it, and pump it as we would water. The depth of this atmospheric ocean cannot be determined as positively as could one of liquid, for the air is elastic and expands as the pressure decreases in the upper layers. Its depth is variously estimated at from 20 to 212 miles. _We can, however, determine very simply how much pressure it exerts per square inch._

UTILITIES AND
ATTACHMENTS

UTILITIES AND ATTACHMENTS.

_Utility_ is a Latin word meaning the same as the Saxon word _usefulness_, hence a utility is something to be used to advantage.

An _attachment_ is that by which one thing is connected to another; some adjunct attached to a machine or instrument to enable it to do a special work; these are too numerous to be described in this work; moreover their number is being so constantly added to that it would be vain to make the attempt. A few examples only follow.

_The Receiver_ is one of the most important and useful parts or connections of a steam pump.

This apparatus, frequently called “Pump and Governor,” and illustrated in Figs. 589, 590 and 591, is designed to automatically drain heating systems and machines or appliances used in manufacturing which depend upon a free circulation of steam for their efficiency. It furthermore is arranged to automatically pump the water of condensation drained from such systems back to the boilers without loss of heat.

By this operation it serves a double purpose: first to automatically relieve the system of the water of condensation constantly collecting therein, thus insuring a free and unobstructed circulation, and, incidentally, preventing snapping and hammering in the piping, which in many cases is due to entrained water; and second, to automatically deliver this water, which in many cases is at the boiling point, directly to the boilers without the intervention of tanks or other devices commonly used. Not only does it relieve the system of a troublesome factor, but it introduces a supply of feed water to the boiler at a temperature impossible otherwise without the use of a special water heater.

The economy resulting from its use is unquestionable, and the satisfactory and increasing use of this machine leaves no doubt as to its efficiency.

As will be seen by the illustrations, the apparatus consists of a cylinder or oval closed receiver, which, together with the pump, is mounted upon and secured to a substantial base, making the whole machine compact and self-contained.

The automatic action of the pump and its speed are controlled by a float in the receiver operating directly, without the use of intervening levers, cranks and stuffing boxes, to open or close a governor valve in the steam supply pipe to the pump, thus making the action of the pump conditional upon the rise and fall of the float in the receiver.

In each of the three receivers shown there is _a ball float_ which appears through the side of the receiver, Fig. 590; these depend upon the principle of specific gravity for their operation. The lever fastened to the ball float operates the throttle valve of the pump; as the vessel fills with water the float rises opens the throttle valve, and starts the pump.

In Fig. 589 is shown the Deane automatic duplex steam pump and _receiver_ fitted with valves for hot water; it is also provided with three separate inlets for convenience in connecting the returns.

In placing the apparatus, it is only necessary to so locate it that all returns will drain naturally towards receiver and that there are no pockets in the piping.

When it is desired to use the automatic receiver as the sole means of feeding the boilers, it will be necessary to introduce a small supply of water from some outside source to equalize the loss which occurs. It is desirable that this water should flow into receiver rather than into discharge pipe.

Fig. 590 shows a Mason steam pump with receiver attached. This pump is described elsewhere at length. Fig. 591 represents the Worthington duplex steam pump with its specially designed receiver.

The _ball cock_ is a faucet which is opened or closed by means of a ball floating on the surface of the water as it rises and falls in the vessel.

In the illustration, Fig. 592, to be seen below the principle of its operation may be discerned. The fall of water in the tank lowers the float and opens the valve (which has in this case a rubber seat) and a rise of water in the tank closes the valve, hence this ball float controls and maintains a constant water level in the tank.

The float is a hollow ball of copper attached to one end of a lever while the other end is pivoted by a pin through it and the side of the shell of the valve. The valve itself is held by a screw to the lever and resembles very much an inverted lever safety valve.

This principle of construction and operation is applied to many devices among which is that described on page 318 relating to pump receivers.

The apparatus constitutes an automatic arrangement for keeping the water at a certain height. It is useful in cisterns, water backs, boilers, etc., where the supply is constant, the demand intermittent.

TANKS AND CISTERNS.

_A tank is an artificial receptacle_ for liquids, thus: _a tank engine_ is one which carries the water and fuel it requires, thereby dispensing with a tender; _tank-iron_ or steel is common plate used in building tanks. Steel is cheaper than sheet-iron. _A cistern is primarily a natural reservoir_—a hollow place containing water; more commonly an underground reservoir or tank. _Closed pressure tanks_ are usually cylindrical shells similar to a horizontal steam boiler, having bumped or rounded heads to save bracing. Closed pressure tanks are used extensively in connection with hydraulic elevators; the requisite pressure for these was formerly derived from an open tank installed upon the roof of the building, but the closed pressure tank, located in the engine room, now very generally takes the place of the open tank.

_A closed pressure tank_ is shown in Fig. 596 in use with a hydraulic elevator.

_A reservoir_ is a place where water is collected and kept for use when wanted, so as to supply a fountain, a canal or a city by means of aqueducts or to drive a mill-wheel or the like.

_A receiving reservoir_ is a principal reservoir into which an aqueduct or rising main, delivers water and from which _a distributing reservoir_ draws its supply.

_A graduated tank_ is one fitted with water gauges and indicating marks, at different heights, between which, the capacity of the tank is shown.

_A ship’s ballast tank_ is the compartment for water to be pumped in and out for the purpose of insuring the proper stability of the vessel, to avoid capsizing and to secure the greatest effectiveness of the propelling power.

_A vat_ is a cistern or tub, especially one used for holding liquors in an immature state, as chemical preparations and tanning liquor for leather. Fig. 594.

_A tub_ is an open wooden vessel formed with staves, bottom and hoops; a kind of short cask, half barrel or firkin, usually with but one head. Fig. 595.

_A gallon_ (U.S.) is equal to 231 cubic inches or 0.13368 cubic feet and weighs 8-1/3 lbs. nearly, (i.e. 8.3356). This is almost exactly equivalent to a cylinder 7 inches in diameter and 6 inches in height.

_The imperial gallon of England_ contains 277.274 cubic inches, and is equivalent to 1.2 U.S. gallons and at 62° Fah. weighs 10 lbs.

_A cubic foot_ contains 7-4805/10000 (7-1/2 nearly) U.S. gallons, and weighs 62-355/1000 (62-1/3 nearly) lbs.

_A barrel_ = 31-1/2 gallons. 1 hogshead = 2 bbls. = 63 gallons.

_The strength of a tank_ is of the first importance; 235-1/2 gallons of water weigh as much as a ton of coal, but unlike the latter, it presses in all directions. Immense losses both of life and property have been caused by the “bursting” or giving way of tanks; particularly of those of a considerable size and elevation.

NOTE.—_Tank Valves._ The “Corcoran” valve is made for either side or
bottom outlet and for 1, 1-1/4, 1-1/2, 2 and 2-1/2 inch pipe; its
action is automatic; the pull by which it is operated is controlled
by a ratchet. This valve closes the pipe inside the tank. It thus
becomes easy to empty the pipes in order to prevent freezing. _The
hoops, lugs and lock nut nipples_ are important parts of a well
constructed tank. _The foundations_ upon which tanks are supported
should be carefully considered, as the average weight of a well made
tank, when full of water, is about five tons to 1000 gallons.

The following table gives the capacity of round tanks or cisterns for each 12 inches in depth, if the tank is 24 inches deep instead of 12 inches, the result would be, twice the number of gallons.

TABLE.

DIAM. GALL.
25 feet 3671
20 „ 2349
15 „ 1321
14 „ 1150
13 „ 992
12 „ 846
11 „ 710
10 „ 587
9 „ 475
8 „ 376
7 „ 287
6-1/2 „ 247
6 „ 211
5 „ 147
4 „ 94
3 „ 53
2-1/2 „ 36
2 „ 23

The contents of cisterns and tanks are estimated either in gallons or in cubic feet. _The weight of water in any cistern or tank_ can be ascertained by multiplying the number of gallons by the weight of one gallon, which is 8-1/3 pounds, 8.333. For instance, taking the largest cistern in the above table containing 3671 gallons: 3671 × 8.33 = 30579.43 lbs. (nearly).

_If the cistern is rectangular_, the number of gallons and weight of water are found by multiplying the dimensions of the cistern to get the cubical contents. For instance, for a cistern or tank 96 inches long, 72 inches wide, and 48 inches deep, the formula would be: 96 × 72 × 48 = 331,776 cubic inches.

As a gallon contains 231 cubic inches; 331,776 divided by 231 gives 1,436 gallons, which multiplied by 8.33 will give the weight of water in the cistern. Fig. 594.

_For round cisterns or tanks_, the rule is: Area of bottom on inside multiplied by the height, equals cubical capacity. For instance, taking the last tank or cistern in the table: area of 24 inches (diameter) is 452.39, which multiplied by 12 inches (height) gives 5527.6 cubic inches, and this divided by 231 cubic inches in a gallon gives 23 gallons. Fig. 595.

_Rule for obtaining the contents of a barrel in gallons._ Take the diameter at the bung, then square it, double it, then add square of head diameter; multiply this sum by length of cask, and that product by .2618 which will give volume in cubic inches; this, divided by 231, will give result in gallons.

STRAINERS FOR SUCTION PIPES,

It is very desirable to place an efficient strainer on the suction pipe of a pump where there is the least suspicion that the water contains any sediment or floating matter.

Several of these useful pump attachments have been already shown, connected with pumps, in previous sections of this work, but a few more are here added.

Fig. 597 exhibits a cross section of a strainer of large capacity of long and satisfactory use. It has a semi-cylindrical vessel located in one side of the side pipe. Holes are drilled through the flat side extending across the diameter of the side pipe; any floating matter which will not pass through the holes collects in this strainer vessel and may be easily removed.

Fig. 598 represents a longitudinal section of this strainer. The top of the chamber is covered by a bonnet secured by a claw having one bolt, so that by unscrewing this bolt the claw and bonnet may be unfastened and the settling chamber with perforated plate withdrawn.

A suction valve with double strainer is represented by Fig. 599, in which the outer screen is raised for cleaning. In lowering, it is guided to its place by the cage around the foot valve chest, as will be seen in Fig. 600, which is a sectional view of this same valve. The suction pipe extension enables the pump to draw water when its surface has fallen below the top of strainer and also below the foot valves. This is often a great advantage where water is scarce and every gallon is needed.

_This foot valve is a “double clack”_ hinged in the center. There are no openings or perforations in the bottom plate. Fig. 601 is a very convenient form of strainer for large pipes and where it is an advantage to have the strainer in the engine-room or near the pump. This strainer, like Fig. 597, can be lifted out for cleaning by removing the claw and bonnet. The chamber may be washed out by removing the plug at the bottom.

A most convenient vacuum chamber and strainer is represented in Fig. 602; it is located near the pump. By removing the suction chamber the basket or strainer may be lifted out by the handle under the arrow. The outlet is generally attached directly to the pump. The pump may be charged by removing the “priming plug” and inserting a hose, with water turned on.

_Steam boiler feed water impurities_ consist mainly of chemical substances which are unaffected—as may be readily supposed—by mechanical devices just described; these impurities are largely invisible being dissolved in the water and hence, also, considering their variety, are most difficult to contend with. How to avoid the actual evils arising from the presence of foreign matter in feed water is of the first importance in steam economy; enormous losses of money, danger to life and property are involved in it. It has been said that there are more millions of treasure to be made by properly “treating” the water which enters the steam generators of the world than can be extracted from its gold mines.

NOTE.—Strangely, investigation has proved that water of this purity
rapidly corrodes iron, and attacks even pure iron and steel more
readily than “hard” water does, and sometimes gives a great deal of
trouble where the metal is not homogeneous. Marine boilers would be
rapidly ruined by pure distilled water if not previously “scaled”
about 1/32 of an inch.

To deal properly with this subject the science of chemistry must be largely drawn upon; chemically pure water is that which has no impurities, and may be described as colorless, tasteless, without smell, transparent, and in a very slight degree compressible, and, were a quantity evaporated from a perfectly clean vessel, there would be no solid matter remaining. Now, in dealing with the impurities inside a boiler, it is to be observed _that in no sense do they change the essential nature of water itself_. The impurities are simply foreign bodies, which have no legitimate place in the boiler, and are to be expelled as thoroughly as possible.

The chemical substances to be eliminated are indicated in the note below. Water, on becoming steam, separates from the impurities which it may have contained, and these form sediment and incrustation. This is an important fact.

_Corrosion_ is simply rusting or wasting away of the surfaces of the metals. Incrustation means simply a coating over.

Several approved recipes and “notes” of instruction for removing sediment and incrustation from steam boilers will be found near the close of this volume.

NOTE.—Analysis of average boiler scale. Parts per 100 parts of
deposit.

Silica .042 parts
Oxides of iron and aluminium .044 „
Carbonate of lime 30.780 „
Carbonate of magnesia 51.733 „
Sulphate of soda Trace
Chloride of sodium Trace
Carbonate of soda 9.341 „
Organic matter 8.060 „
------------
Total solids 100. parts

The percentage only of each ingredient the scale is composed of is
given, as it cannot be told how much water was evaporated to leave
this amount of solid matter.

THE WATER METER.

Water meters, or measurers, are constructed upon two general principles: 1, an arrangement called an “_inferential meter_” made to divert a certain proportion of the water passing in the main pipe and by measuring accurately the small stream diverted, _to infer_, or estimate the larger quantity; 2, _the positive meter_; rotary piston meters are of the latter class.

LONGITUDINAL SECTION.
TRANSVERSE SECTION.
FIGS. 604, 605.]

The distinctive difference between the two is, that the positive meter measures water by means of a chamber alternately filled and emptied. In most of these the flow of water ceases when, by any derangement, the motion of the piston is interrupted. But neither the motion nor the stoppage of the inferential meter has any effect upon the water delivery, so that at times a large amount of water may pass unrecorded. Another important mechanical difference is that the motion of a piston meter should be slow, while that of the inferential wheel is, and must be, rapid; this has much to do with their relative durability.

Fig. 603 is a perspective view of the _Worthington water meter_, the details of which are shown in the Figs. 604 and 605, the recording or “dial” mechanism is also shown in Fig. 606.

The internal arrangement of the meter is shown in longitudinal section, Fig. 604, and the transverse section, Fig. 605, on the opposite page.

The plungers, AA, are closely fitted into parallel rings. The water passes through the inlet and port I, and is admitted under pressure into chamber, D, at one end of each plunger alternately, while the connection is made between the chamber at the other end of the outlet. Thus, the plunger in moving displaces its volume, discharging it through its outlet. The arrangement is such that the stroke of the two plungers alternates, the valve actuated by one admitting pressure to the other. The plungers are brought to rest at the end of the stroke by the rubber buffers, EE. One plunger imparts a reciprocating motion to the lever, F, which operates the counter movement through the spindle and ratchet gear as shown. Thus, it will be seen that the counter is arranged to move the dial pointers once for every four strokes or displacements, and that water cannot pass through the meter without registration, for, in order to pass through, it must be displaced by the plungers, and, therefore, recorded by the movement of the lever and counter mechanism; nor can there be an over-registration, because the plungers cannot move without displacing the fluid.

_To read the dial._ The counter usually registers in cubic feet, one cubic foot being 7.48 gallons U. S. standard. When desired for special services, counters are furnished reading in U. S. gallons, Imperial gallons, and Hectolitres. This counter is read in the same way as the registers of gas meters.

The following example and directions may be of use to those unacquainted with this method:

If the pointer is between two figures, the smaller one must invariably be taken; suppose the pointers of the dial stand, as shown in Fig. 606; starting at the dial marked 10 cubic feet, we get the figure 4; from the next marked 100 cubic feet, the figure 7; from the next marked 1,000 cubic feet, the figure 8, and from the next marked 10,000 cubic feet, the figure 6; the reading is 6,874 cubic feet. The pointer on the 100,000 cubic foot dial being between the 0 and the 1 indicates nothing. By subtracting the first reading taken from that taken at the next observation, the consumption of water for the intermediate time is obtained.

_A steam trap_ is an apparatus to remove the water of condensation from steam pipes for heater coils and radiators without permitting steam to escape; the steam trap is also used to remove the water of condensation or entrained water caught in steam separators, located near the steam engine in the connecting pipes between the engine and boilers.

The problem of saving the water of condensation without allowing the escape of steam is a difficult one, in view of the early wear of the valves and the valve seats.

Fig. 607 represents the Anderson improved steam trap. This trap shows at all times what it is doing by the position of the water in the glass gauge attached to the side of the trap and in front. The water of condensation enters at the upper right-hand side, A, Fig. 608, where all scale and dirt from the pipes are caught in the settling chamber which contains a strainer. This strainer can be lifted out with its contents of dirt and scale and replaced in a few moments by unscrewing the plugs, shown in Fig. 607 just above the inlet. The discharge is connected at the lower left-hand side. The bonnet which contains the valve float and lever can be removed without breaking any pipe joints, or the valve and seat may be removed by simply unscrewing the cap, H, at the lower left-hand side without disturbing the bonnet at all. It will be understood that this trap does not dump, but the discharge of water is regulated by a ball float and valve, hence there are really but two working parts to this trap, viz.: the ball float and valve. Water is permitted to pass this trap as fast as it comes along, and no considerable quantity ever accumulates within this trap at any one time.

The sectional view, Fig. 608, gives a fair idea of the interior of this trap, being a longitudinal section on center line. The by-pass valve, C, so-called, is not a valve, but is simply a threaded stem and is used to hold up the float in emptying the trap. To blow out the trap this by-pass is screwed in as far as it will go without forcing, same motion as in closing a globe valve. When the water has been discharged, this by-pass is unscrewed to its former position, which permits the float to drop, closing the valve when the reservoir fills with water, to its normal position.

With three inches of water in the glass the valve is closed and sealed so that no steam can escape. The dotted line represents the water level. The sediment chamber, E, prevents dirt and scales in the pipes from getting into the valve.

The ball float is made of seamless copper with heavy bands to prevent the ball from collapsing under high pressure. These traps work on all pressures from 150 pounds pressure down, and are also made for higher pressures in special cases—will work against back pressure and with exhaust steam alone—are made in seven sizes, _i.e._, from 1/2 inch to 2-1/2 inches, inclusive.

TOOLS
VALVES
AND PIPING

TOOLS.