FOOTNOTE:

FOOTNOTE:CEight-inch preferred, this being the more common size for valves, fittings, and pipes.These suction pipe sizes, although larger than common for trade pumps of the same size, are believed to be amply justified by experience, and exert a powerful influence toward enabling the pump to run smoothly at high speed with water cylinders filling perfectly at each stroke. No defect is more common than restricted suction pipes.

CEight-inch preferred, this being the more common size for valves, fittings, and pipes.These suction pipe sizes, although larger than common for trade pumps of the same size, are believed to be amply justified by experience, and exert a powerful influence toward enabling the pump to run smoothly at high speed with water cylinders filling perfectly at each stroke. No defect is more common than restricted suction pipes.

CEight-inch preferred, this being the more common size for valves, fittings, and pipes.

These suction pipe sizes, although larger than common for trade pumps of the same size, are believed to be amply justified by experience, and exert a powerful influence toward enabling the pump to run smoothly at high speed with water cylinders filling perfectly at each stroke. No defect is more common than restricted suction pipes.

b.A single suction entrance at the end of the pump is to be provided unless otherwise specified by the purchaser.

Some situations render desirable side suction entrances, for permitting drafting water from two different sources of supply. These additional openings are to be considered as extras. Ordinarily, the purchaser can provide for such situations by proper piping at the single end suction entrance.If there is to be but one suction opening on casting, this had best be at center, for the reason that, if suction pipe ever gets to leaking air, this air stands a better chance of being distributed equally to the two plungers, and has less tendency to make the pump run unevenly.

If there is to be but one suction opening on casting, this had best be at center, for the reason that, if suction pipe ever gets to leaking air, this air stands a better chance of being distributed equally to the two plungers, and has less tendency to make the pump run unevenly.

c.Standard flanges and standard bolt layouts as adopted by the Master Steam Fitters, July 18, 1894, must be used on all the above pipe connections, as per table given below.

SCHEDULE OF STANDARD FLANGES.

Size of Pipe ×Diam.of Flange.DiameterofBolt Circle.NumberofBolts.SizeofBolts.FlangeThicknessat Edge.Inches.Inches.Inches.Inches.3×71⁄2645⁄8×21⁄213⁄1631⁄2×81⁄2745⁄8×21⁄27⁄84×971⁄243⁄4×23⁄415⁄1641⁄2×91⁄473⁄483⁄4×315⁄165×1081⁄283⁄4×315⁄166×1191⁄283⁄4×317×121⁄2103⁄483⁄4×31⁄411⁄168×131⁄2113⁄483⁄4×31⁄21⁄89×15131⁄4123⁄4×31⁄211⁄810×16141⁄4127⁄8×35⁄813⁄1612×1917127⁄8×33⁄411⁄414×21183⁄4121×41⁄413⁄8

Do not drill bolt holes on center line, but symmetrically each side of it.

On steam and exhaust openings loose flanges threaded for wrought-iron pipe must be provided.

Where the situation will not permit of a standard flange on exhaust opening for lack of room, a special flange threaded to fit the proper size wrought-iron pipe may be used.

a.Air and vacuum chambers in accordance with the sizes given in the following table must be provided with all pumps. If the air chamber is cast iron, the pump manufacturers must warrant that it has been subjected to a hydraulic test of 400 lbs. per square inch before it is connected to pump.

It is to be thoroughly painted inside and out to diminish its porosity.

SIZE OF VACUUM AND AIR CHAMBERS.

Vacuum Chamber isto contain:—Air Chamber isto contain:—500-gallon pump.13 gallons.17 gallons.750 „ „18 „25 „1,000 „ „24 „30 „1,500 „ „30 „40 „

The air chamber, combined with connections for discharge pipe, relief valve, and hose valves, should be carefully designed to make the whole weight as small as possible. Keeping this weight down makes the pump run steadier and brings less strain on the flanges at high speeds.An air chamber of hammered copper and warranted tested under a hydraulic pressure not less than 300 lbs. per square inch is a little better than cast iron as it holds air better, and being lighter it wrenches and strains the pump less when running fast and shaking, but because it costs from $25 to $50 more than cast iron, it is not often adopted.

An air chamber of hammered copper and warranted tested under a hydraulic pressure not less than 300 lbs. per square inch is a little better than cast iron as it holds air better, and being lighter it wrenches and strains the pump less when running fast and shaking, but because it costs from $25 to $50 more than cast iron, it is not often adopted.

b.The vacuum chamber must be attached to the pump in the most direct way practicable, but provision must be made for attaching it in such manner as not to prevent readily taking off the cylinder heads.

c.Every vacuum chamber should be provided on one side near the top with a1⁄4-inch pipe hole plugged. This to be used for attaching a vacuum gauge if desired.

a.A pressure gauge of the Lane double tube spring pattern with 5-inch case, must be provided with the pump, and connected near to inboard side of air chamber, as shown inFig. 12, by a1⁄4-inch cock, with lever handle.

The dial of this gauge should be scaled to indicate pressures up to 240 lbs. and be marked “WATER.”

This kind of gauge is used on locomotives and is the best for withstanding the vibration which causes fire-pump gauges to be often unreliable. Moreover, this double spring form is safer against freezing.

a.Hose valves must be attached to the pump (and included in its price) as follows:—

For the 2 stream or 500-gal. pump, 2 hose valves.For the 3 stream or 750-gal. pump, 3 hose valves.For the 4 stream or 1,000-gal. pump, 4 hose valves.For the 6 stream or 1,500-gal. pump, 6 hose valves.

These are to be 21⁄2-inch straightway brass valves, without cap, and similar and equal in quality to those made by the Chapman Valve Company, the Ludlow Valve Company, or the Lunkenheimer Company.The hose-screw at end of these valves is to be fitted to a hose coupling furnished by the customer, or where this cannot be procured may be left with the thread uncut.To accommodate locations where all the lines of hose must lead off from one side of the pump—makers can furnish a spool piece or special casting to which the hose valves can be attached—but this is an extra not included in the regular price.

These are to be 21⁄2-inch straightway brass valves, without cap, and similar and equal in quality to those made by the Chapman Valve Company, the Ludlow Valve Company, or the Lunkenheimer Company.

The hose-screw at end of these valves is to be fitted to a hose coupling furnished by the customer, or where this cannot be procured may be left with the thread uncut.

To accommodate locations where all the lines of hose must lead off from one side of the pump—makers can furnish a spool piece or special casting to which the hose valves can be attached—but this is an extra not included in the regular price.

Fig. 11.

a.A safety or relief valve of the Ashton, Crosby, American, or other make agreed upon in writing with this office, is to be regularly included in the price, and is to be attached to each pump; preferably extending horizontally inboard from base of air chamber, as shown inFig. 12, so that its hand-wheel for regulating pressure is within easy reach. This hand-wheel must be marked very conspicuously as shown inFig. 11.

b.This valve is to be set ordinarily at a working pressure of 100 pounds to the square inch, and is to be of such capacity, that when set at 100 pounds it can pass all the water discharged by the pump at full speed, at a pump pressure not exceeding 125 pounds per square inch.

For 500-gallon pump a 3 inch valve.For 750-gallon pump 31⁄2inch valve.For 1,000-gallon pump 4 inch valve.For 1,500-gallon pump 5 inch valve.

The relief valve must discharge in a vertical downward direction into a cone or funnel secured to the outlet of the valve.(See Art. 44.)

Fig. 12.

The valve must be so attached to the delivery elbow and discharge cone by flange connections as to permit of its ready removal for repairs without disturbing the waste piping.

a.This cone should be so constructed that the pump operator can easily see any water wasting through the relief valve, and its passages should be of such design and size as to avoid splashing water over into the pump room.

b.The cone must also have a one-inch tapped connection for the air-vent pipe required by Art. 45, and the arrangement must be such that the pump operator can easily tell whether water is coming from the air pipe or is wasting through the relief valve.

c.The cone should be piped to some point outside of the pump house where water can be wasted freely, the waste pipes being as below.

SIZE OFPUMP.DIAMETER OF WASTEPIPE FROM CONE.500-gallon.5 inches.750 „6 „1,000 „7 „1,500 „8 „

The waste pipe can pass down to floor between the yokes at middle of pump. It should be piped in such a way that steam and gases from other drains or waste pipes will not work back through it, and, by being troublesomein the pump room, suggest the covering of the cone in any way, as it is desirable that the pump operator should always be able to see instantly any waste from the relief valve or air vent.This cast-iron cone, connected to the safety valve and air vent, is included in price of pump, but the waste pipe beyond it is not.

This cast-iron cone, connected to the safety valve and air vent, is included in price of pump, but the waste pipe beyond it is not.

Fig. 13.

a.An air vent with a brass gate valve and brass pipe for connecting up, must be provided and connected with delivery elbow and discharge cone.

b.The size of this air vent should be one inch for 500-gallon and 750-gallon pumps, and one and one-fourth inches for the 1000-gallon and 1500-gallon sizes.

c.The hand wheel of this valve must be marked as perFig. 13. The lettering must be very open, clear and distinct, not liable to be obstructed by grease and dirt, and of a permanent character.

The object of this valve is to reduce the pressure above force valves and secure a prompt riddance of all air that may come through the water cylinders when first starting up.This valve, of course, should be closed when once pump is under way, to prevent waste of water.

The object of this valve is to reduce the pressure above force valves and secure a prompt riddance of all air that may come through the water cylinders when first starting up.

This valve, of course, should be closed when once pump is under way, to prevent waste of water.

a.Each pump must be fitted with a set of brass priming pipes and valves, according to either one or the other of the following methods:

b.For 1,000 and 1,500 gallon pumps, the priming pipes must be 11⁄4inches. For the 500 and 750 gallon pumps, the pipes must be 1 inch. Pump-makers are to furnish these pipes and the fittings called for below, and are to connect them up providing a 2-inch outlet, looking upwards, ready for the supply from the priming tank.

The pipe from the priming tank to this outlet should be at least 2-inch, and may be of iron, and is to be furnished by the purchaser. All parts furnished by the pump-maker are to be of brass, and are to be included in the price of the pump.

Controllable Valve Arrangement.

c.Four 2-seat controllable valves, one for each pulsation chamber, and of the general type illustrated inFig. 14, must be provided. In these the inlet of water and outlet of air are simultaneously opened and closed by the pump operator.

Fig. 14.

Objection has been raised to this double-seated valve from the possible difficulty of keeping both seats tight. If desired, the valve may be fitted with a flange instead of a screw connection, and the stem between the two seats somewhat enlarged and provided with a suitable spring, thus giving flexibility between the two seats and preventing all trouble from uneven wear.

d.The hand-wheel of each of these valves must be marked as perFig. 15, so that the pump operator I may clearly understand their use. The lettering must be very open, clear and distinct, not liable to be obscured by grease and dirt, and of a permanent character.

Fig. 15.

Fig. 16.

e.There must be provided and fitted to each combined valve a check and umbrella-top air vent, as shown inFig. 16. This fitting must have a clear passageway through it, the full equivalent of a1⁄2-inch bore.

The check-valve is to permit the outflow of air, but to prevent the influx when the plunger is sucking.This method is preferred to the one using rubber priming checks, as now and then a rubber valve will stick on its seat and thus prevent priming of one of the chambers. In this arrangement the pump operator has absolute control over the priming water into each chamber.Another advantage is that the connection of the air-vent with the priming valve ensures that the air-vents will be opened; and further, by the vigorous spurting out of water as soon as the pump is primed, the pump operator is reminded that the priming valve should be closed.Should the pump operator, however, through a mistaken idea of the proper method of operation, think that the priming should be continued until all air was exhausted from the suction pipe and the pump running in normal condition, there would be some by-passing between chambers, but as there is a free vent for the air, the main result would be simply to limit the amount of air exhausted per stroke, from the main suction, by the amount of water which entered a chamber in this way. The amount of water thus entering, however, would not be appreciably greater than that which would enter from the priming-tank with the check-valve arrangement.If, even in spite of the warning given by the spurting air-vents, the pump operator should neglect to close the priming-valves when the pump was running normally, the priming-tank would eventually be overflowed; but this would not be as serious as the drawing in of air from an exhausted priming-tank, which would result with the check-valve method, were the main 2-inch valve similarly neglected.

The check-valve is to permit the outflow of air, but to prevent the influx when the plunger is sucking.

This method is preferred to the one using rubber priming checks, as now and then a rubber valve will stick on its seat and thus prevent priming of one of the chambers. In this arrangement the pump operator has absolute control over the priming water into each chamber.

Another advantage is that the connection of the air-vent with the priming valve ensures that the air-vents will be opened; and further, by the vigorous spurting out of water as soon as the pump is primed, the pump operator is reminded that the priming valve should be closed.

Should the pump operator, however, through a mistaken idea of the proper method of operation, think that the priming should be continued until all air was exhausted from the suction pipe and the pump running in normal condition, there would be some by-passing between chambers, but as there is a free vent for the air, the main result would be simply to limit the amount of air exhausted per stroke, from the main suction, by the amount of water which entered a chamber in this way. The amount of water thus entering, however, would not be appreciably greater than that which would enter from the priming-tank with the check-valve arrangement.

If, even in spite of the warning given by the spurting air-vents, the pump operator should neglect to close the priming-valves when the pump was running normally, the priming-tank would eventually be overflowed; but this would not be as serious as the drawing in of air from an exhausted priming-tank, which would result with the check-valve method, were the main 2-inch valve similarly neglected.

Rubber Check Valves.

f.Four rubber check valves, one for each pulsation chamber, and similar to ordinary pump valves, must be provided. The chambers for these should preferably be made as a part of the pump cylinder, thus securing a compact arrangement.

Figure 12shows this arrangement in outline.

g.The valve seat should have three ribs to the central hub, supporting the rubber valve. The net port area through the valve should be not less than 11⁄2square inches.

This valve seat should rest in an inverted position, and can be so fitted up as to be readily removed. The valve stems can be of the removable type screwing into the seat, but must be made long enough to receive a check nut on the opposite side of seat. This will effectually lock the stem in place.

h.Care must be taken to arrange the water passages through and about these priming checks, so as to avoid all air pockets and so as to reduce to a minimum the possibility of the valves becoming choked up by refuse.

i.The valve seats, stems and all parts must be of composition and of strong rugged design, so fitted up that there is the least chance for the rubber valves to stick, and with all parts securely put together the valves must be readily accessible.

j.The valve springs must have only sufficient strength to keep the valves on their seats, so that they will freely open even with the low head of priming water often existing.

Fig. 17.

k.There must be provided, and attached to the top of each plunger chamber, a brass check valve and air cock with umbrella top, as shown inFig. 17. This cock and valve must have a clear passageway through them—the full equivalent of a1⁄2-inch bore.

The check valve is to permit the outflow of air, but to prevent the influx when the plunger is sucking. Cocks with lever handles are used, as these show clearly whether they are open or shut.

l.There must also be provided a 2-inch brass gate valve for the general control ofthe water to the four-check valves. The hand wheel of this valve must be marked as perFig. 15. The lettering must be very clear, open, and distinct, not liable to be obscured by grease, and of a permanent character.

It is essential for a properly working pump that the main 2-inch priming-valve should be closed as soon as the pump is primed. Otherwise, water will be drawn from the priming tank, lessening the lifting power of the pump through the main suction, and if this is continued the priming tank will often be exhausted and air drawn into the pump, interfering with its proper action. It is for this reason that the marking on the priming valve is required.For all average situations, either method of priming permits of getting the pump under way in a very few minutes, but, for cases where the suction pipe is over 300 or 400 feet in length, or sometimes where the lift is over 18 feet, or where there is a combination of long length and lift within these limits, so much time is consumed in exhausting the air from the suction pipe that it becomes desirable to supplement this method.For such situations, a steam ejector connected to the suction pipe near the pump is advised, and may be required in addition to the regular priming pipes and tank. The size of the ejector should be sufficient to exhaust the suction pipe within about three minutes. Such ejectors will be considered as extras not included in the ordinary pump fittings.For cases where pump can only take its suction under a head, if absolutely certain that the level of the suction water will never fall below level of center of pump, these priming pipes may be omitted, but openings for them into the pump shell must be provided and capped or plugged.A foot valve on a fire-pump suction is not advisedexcept in very rare cases, as with a lift of 18 feet or a suction pipe 500 feet or more long. A foot valve is not needed when there is a good efficient set of priming arrangements as described above and it is commonly found this gives a false sense of security, and that with a fire-pump left standing several days the water will often be found to have leaked back, so that it is no better than if no foot valve had been used.A foot valve must of necessity generally be located where it is inaccessible for quick repairs, and as they grow old, foot valves are often a source of trouble. Where a suction pipe is exposed even slightly to frost, a foot valve is specially objectionable.A priming tank is provided for the purchaserin all cases where there is ever to be any lift on the suction. It is generally advised that this tank have a capacity of one-half of what the pump can throw at full speed in a minute. This means 250 gallons for a 500-gallon pump and 500 gallons for a 1,000-gallon pump, etc. It is the intention to make the pump a truly “independent source” of supply, therefore the need of a special priming tank.

For all average situations, either method of priming permits of getting the pump under way in a very few minutes, but, for cases where the suction pipe is over 300 or 400 feet in length, or sometimes where the lift is over 18 feet, or where there is a combination of long length and lift within these limits, so much time is consumed in exhausting the air from the suction pipe that it becomes desirable to supplement this method.

For such situations, a steam ejector connected to the suction pipe near the pump is advised, and may be required in addition to the regular priming pipes and tank. The size of the ejector should be sufficient to exhaust the suction pipe within about three minutes. Such ejectors will be considered as extras not included in the ordinary pump fittings.

For cases where pump can only take its suction under a head, if absolutely certain that the level of the suction water will never fall below level of center of pump, these priming pipes may be omitted, but openings for them into the pump shell must be provided and capped or plugged.

A foot valve on a fire-pump suction is not advisedexcept in very rare cases, as with a lift of 18 feet or a suction pipe 500 feet or more long. A foot valve is not needed when there is a good efficient set of priming arrangements as described above and it is commonly found this gives a false sense of security, and that with a fire-pump left standing several days the water will often be found to have leaked back, so that it is no better than if no foot valve had been used.

A foot valve must of necessity generally be located where it is inaccessible for quick repairs, and as they grow old, foot valves are often a source of trouble. Where a suction pipe is exposed even slightly to frost, a foot valve is specially objectionable.

A priming tank is provided for the purchaserin all cases where there is ever to be any lift on the suction. It is generally advised that this tank have a capacity of one-half of what the pump can throw at full speed in a minute. This means 250 gallons for a 500-gallon pump and 500 gallons for a 1,000-gallon pump, etc. It is the intention to make the pump a truly “independent source” of supply, therefore the need of a special priming tank.

Older Priming Arrangements.

The form of priming arrangement heretofore used, with metal check valves, one main 2-inch priming valve, and 1-inch priming pipes, separate controllable air cocks, may be retained on all pumps at present in service, and will be considered satisfactory, if kept in good order.

If in any case such checks give trouble the priming arrangement may be changed and valves likeFig. 14or rubber checks as described in sectionsf-j, made up in detachable form,Dmay be put on if desired, where the connections on the pump permit them.

Where neither method is desired or where neither is feasible the faulty checks may be replaced by a special type such as are now made for this use, by the Locke Regulator Company, of Salem, Mass. These are 1-inch check valves, adapted to use a small disc of medium hard rubber, similar to a pump valve.

These fittings are very near the dimensions of the commercial check valve, so that with slight shortening of piping connections they will fit into the present arrangements, and give satisfaction.

a.Five brass drain cocks, each with a lever handle and of1⁄2-inch bore, are to be provided, and located one on each end of each water cylinder, and one above the upper valve deck.

Care should be taken to select a pattern of cock whose passageway is the practical equivalent of a1⁄2-inch hole. Some patterns of1⁄2-inch commercial cocks although threaded for1⁄2-inch pipe thread have but a1⁄4-inch hole through them. Such are not acceptable.

FOOTNOTE:DSuch detachable rubber check valves are now made up in regular form by the George F. Blake Mfg. Co., East Cambridge, Mass.

DSuch detachable rubber check valves are now made up in regular form by the George F. Blake Mfg. Co., East Cambridge, Mass.

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