Plumbing - Building Water Supply Part 12

Both pump do not operate simultaneously. A control device causes the pumps to be activated alternately. Both pumps operate only if there is more flow into the basin than one pump can handle.

Each pump must be large enough to handle the entire flow by itself. This is a safety precaution in the event of failure of one of the pumps. Pumps that will handle solids up to 3" size are recommended.

Depth of basin.

Distance between top of basin and basin inlet.

Size of basin.

Solid vibration free foundation.

Size of piping.

Elimination of noise.

Sump depths are determined by the lowest line entering the sump, incremental pump depths (usually 6").

Minimum recommended clearances below the pump suction (usually one and half to two times the pipe diameter.

A minimum of 3' should be provided from the invert if the lowest line entering the bottom of the sump.

The distance between the maximum liquid level and the basin cover should be 1/3 of the storage area between the high and low liquid levels, but not less than 2'.

Discharge piping must always be as large or larger than the size of the pump connection, as short and direct as possible and supported independently of the pump. Any refusers required should be eccentric for complete drainage.

A check valve should be installed to prevent backflow and a gate valve for maintenance of the pump and check valve. Weighted-lever check valve are used to ensure positive shut-off. Resilient-type or aluminum-flapper check valves can be used where noise may be a problem.

In critical areas, the pump base plate should be installed on rubber or another resilient isolation material and flexible connectors

Installed in discharge piping.

1. Sump pit (basin) inlet. 2. Check valve. 3. Gate valve. 4. Ejector discharge to gravity drainage system. 5. Vent line to atmosphere. 6. Float switch. 7. High water alarm. 8. Manhole cover.

The discharge from the two pumps is yoked together into a single pipe line, check valves must be installed to prevent the discharge from the one pump entering the other discharge line. Gate valves are installed in the discharge piping to aid in pump maintenance. The gate valves location on the discharge side of the check valve assures that the check valve can be isolated from the discharge of the other pump.

1. Wet pit installation. | 2. Dry pit installation.

Where floor space (on the top of pit) is limited and flooding is marginal and it require a sump pump in the dry section of pit.

Generally pumps are floatcontrolled, whereby a floating ball and rod, micro switch, mercury float switch or water-level detector starts and stops the pump at different adjustable water levels. They should not start more often than every 3 to 5 minutes and operate for 10 minutes. In critical applications, a high-water level alarm that activates an alarm device when the water level rises above a predetermined point is used. It may be installed to operate in parallel from one float device, operate separately from different water levels, alternate periodically, or operate in a lead-lag arrangement to prolong the life of each pump.

1. A float. 2. Float rod. 3. Rod Guide. 4. Adjusting stops. 5. Gas tight pedestal. 6. Float switch.

Provide a positive means of alternating the operation of the two pumps on a duplex system.

1. Be sure that lubrication of the pump and driver is performed. 2. All valves are in their normal operating position . 3. The basin has been cleaned of debris.

1. Low capacity: predominately of the centrifugal type, single diffuser type. 2. For high pressure and high capacity installations: multy-stage.

Supply the water to a boiler in sufficient quantity and pressure to maintain a safe water level in the boiler. The pressure which the pump produces must exceed the boiler pressure. This differential must also take into consideration the various resistances that the water will be subjected to as it leaves the pump outlet. The pumps are controlled bylevel controls on the boiler. They are normally sized to accommodate system surges and also to provide for the addition of a fresh water as required. Low water cut-off switches and alarms are often included in the boiler feed system.

1. ! Return to the system line. 2. Inlet strainer. 3. Drain line from return and tank. 4. Boiler feed receiver. 5. Boiler feed pump(s). 6. Pump discharge line. 7. Make-up water supply with manual bypass. 8. Air gap fitting. 9. Overflow loop with loop fill, drain land vent lines. 10. Full size open air vent.

Compressed air is used for automatic controls on heating, cooling, ventilating and air conditioning equipment. The controller , a thermostat for instance, varies the amount of compressed air passing through a circuit of the system. This compressed air operates the controlled devices, valves or damper operators in a building, on demand of the thermostat.

1. Pressure switch. 2. Motor. 3. Drive belt. 4. Compressor. 5. Intake filter. 6. Tank. 7. Drain cock. 8. Outlet filter with drain cock, 9. Reducing pressure valve with high and low pressure gages. 10. Main air line. 11. Branch air line to thermostat. 12. Valve operator.

On the downstroke of the piston a partial vacuum is created inside the cylinder and atmospheric pressure causes air to force the suction valve open and fill the cylinder. On the upward stroke of the piston, the air is compressed and the pressure inside the cylinder increases. This holds the suction valve closed and forces the air to flow out of the cylinder past the discharge valve and into the discharge pipe.

The main requirement for air compressors in a level 1 (hospital) installation is to supply air with no added contamination. The air is used to support life and when mixed with other gases, the proper results can be achieved. The air in a medical gas system can be used for no other purpose than direct patient therapy. That is why the cleanliness and efficiency is so critical.

The National Fire Protection Association Standard NFPA-99.

Such use could increase service additional opportunities for contamination.

1. An oil-less. | 2. An oil-free.

Type B compressors contain an oil lubricated cross head piston and crank mechanism., and a dry cylinder compression chamber that, are isolated by means of at least two seals. These seals ensure a 99.99% possibility of oil-free air. With wear of the seals, oil migration into the discharge line will possibly increase, therefore the interconnecting shaft be open for visual inspection.

They have oil-filled crankcases; thus oil vapor is always present in the compression chamber and discharge line. Filtration, the common solution, is expensive and requires constant maintenance. In commercial and industrial application, a conventional lubricated compressor is acceptable; in medical air systems, they are prohibited.

It is one way to meet the goal of 100% oil-less air: use self-lubricated pistons and skirts, as well as sealed for life bearings. The crank mechanism operates in what Amounts to a dry state, assuring no oil in the discharge line.

1. An oil-less piston compressor. | 2. A liquid ring compressor.

There is only one moving part, the impeller, and no metal to metal contact. The service water enters the compressor after passing through a strainer, solenoid valve, flow control valve, backflow preventer and dielectric fitting. The water combined with the spinning impeller compresses the air and discharge both water and air. This system draws air through a filter into the inlet of the compressor and discharges the air through a dryer into a receiver tank, using water to compress the air.

1. Monitors with alarms to insure against high temperatures, high water levels (in liquid ring compressors), dew point, carbon monoxide and other gases. 2. Two or more compressors , running alternately, with dedicated disconnect switches.

Steel pipe must be used above ground. The only exception to this requirement is when you connect to underground suction and underground discharge piping. Where corrosive water conditions Acosta, steel suction pipe shall be galvanized, or painted on the inside, prior to installation, with a paint recommended for submerged surfaces. Thick bituminous linings are not permitted. Section of steel piping are joined by means of screwed, flanged (with flanges welded to pipe preferred), mechanical grooved joints, or other approved fittings.

Small knobs or buttons of rust on the inside of the pipe.

By increasing flexibility between major parts of the piping. Flexibility between major parts of the piping. Flexibility can be provided by the use of flexible couplings at critical points, and by allowing clearances at walls and floors.

Large systems and systems in high buildings can experience objectionable water hammer when an automatic controlled fire pump shuts down. When such conditions are expected, a listed (approved) check valve must be installed in the pump discharge piping and it should be of the anti-water hammer type. A listed indicating gate or butterfly valve must be installed on the system side of the check valve.

1. Pressure gages. 2. Relief valves. 3. Water measuring devices. 4. Hose valves. 5. Meters. 6. Jockey pumps.

1. a pressure gage with a dial not less than 3 1/2" in diameter shall be connected near the discharge casing along with a 1/4" gage valve or cock. The dial must indicate pressure at least twice the rated working pressure of the pump, but not less than 200 psig. 2. A compound pressure and vacuum gage, with a dial not less than 3 1/2" in diameter must be connected to the suction pipe near the pump along with a one-quarter inch gage valve or gage cock. The face of the dial can read in inches of mercury (Hg) or pounds per Square inch for the suction range.

Each pump driven by an electric motor shall be provided with an automatic relief valve listed for fire pump service and set below its shutoff or churn-pressure at minimum expected suction pressure. It must provide circulation of sufficient water to prevent the pump from overheating when operating with no discharge, which could otherwise cause the bearings to seize.

The relief valve must be set to prevent pressure on the fire-protection system exceeding what the system is designed to withstand. The relief valve must be located between the pump and the pump-discharge check valve and be so attached that it can be readily removed for repairs without disturbing the piping.

Maximum pressure is developed at a zero flow rate by afire pump.

The 175 psig.

A water-measuring device must be provided to test the pump and the suction supply at the maximum flow available from the fire pump.

The most common devices for testing pump discharge capacity are listed hose valves mounted on a header. The hose valve piping connects to the pump discharge piping between the discharge check valve and the discharge gate valve. They should be outside the pump room or pump house. The hose valve header may be omitted when its main function is to provide a method of pump and suction pipe testing and if there are other adequate pump testing facilities, such as yard hydrants, wall hydrants, or standpipe hose valves.

Metering device for pump testing shall be listed and capable of water flow of not less than 175% of the pump's rated capacity. The minimum size meter for a given pump capacity may be used where the meter system piping does not exceed one hundred feet equivalent length . Where it exceeds, the next large size piping shall be used to minimize friction loss.

It is usually required with automatically controlled fire pumps. A jockey pump is a high-pressure, low capacity pump. It is used to replenish system pressure lost through system leaks without undue wear on the fire pump. In a jockey pump system a small pump, motor, and controller/pressure switch is installed in the piping system.

As a pressure maintenance or make-up pump.

Probably the easier way to differentiate between the two is to note that the supply to a horizontal pump is piped from a water source (a city connection or a tank) while the impellers of a vertical pump sit in the supply (a wet pit or a well).

1. A horizontal-shaft split-case pump. 2. An end-suction pump. 3. An in-line pump.

It is specially tested for fire service applications where reliability of performance is of vital importance. They are characterized by easy access to all working parts, rugged construction, liberal water passages, and efficient operation. It has one flanged fitting for connection to the water supply and another for connection to the fire protection system. A shaft extends out one end to connect to the power source.

The water inlet is at the end of the pump rather than on the side. The discharge may be out either side or the top of the pump unit.

It is a variation of the end-suction style with the inlet and outlet connection in a straight line for installation in a straight line of piping. The motor is mounted directly on the pump so that no baseplate, coupling, etc. are needed. The motor is mounted vertically over the pump so that a minimum of floor space is required.

1. The suction pipe must be capable of maintaining a gage pressure of at least zero at the pump suction flange, with all pumps connected to the supply pipe operating at 150% of their rated capacity. 2. When the suction pipe is not the same size as the pump suction flange, use an eccentric tapered reducer with flat side on the top. 3. Elbows with a centerline plane parallel to the pump shaft must be avoided, unless the distance between the flange of the suction inlet and the elbow is greater than ten times the suction pipe diameter.

It must be a listed OS&Y valve. While butterfly valves are permitted on the pump discharge, they must not be installed on the supply side of a fire pump or jockey pump within 50' of the pump suction flange. Turbulence caused in water passing a butterfly valve would cause cavitation. Where the suction supply is from public water mains, the gate valve should be located as far as is practical from the suction flange on the pump. Where it comes from a stored water container, the gate valve should be located at the outlet of the container.

Device or assembly that will stop, restrict the starting, or restrict the discharge of a fire pump.

Shutoff valve.

Check valves and back flow prevention devises and assemblies required by other NFPA standards or by the authority having jurisdiction.

Pressure sensitive flow control valves listed for fire pump, service where the authority having jurisdiction requires that positive pressure be maintained on the suction piping.

As long as they are arranged to activate an alarm if the pump suction pressure or water level falls below a predetermined minimum.

Pumps which are automatically controlled must be provided with an approved float-operated air release not less than 1/2" in size to release air from the pump automatically. This is not required for end suction pumps with a top centerline discharge, or on in-line pumps.

A clockwise (CW), or right-hand, rotation. A counterclockwise (CCW), or left-hand, rotation.

With clockwise rotation.

Stand at the driver end and facing the pump. If the top of the shaft revolves from the left to the right, the rotation is clockwise. If the top of the shaft revolves from right to left, the rotation is counterclockwise.

A vertical-shaft centrifugal pump with rotating impellers suspended from the pump head by a column pipe. This column pipe also serves as a support for the shaft and bearings.

When the water source is located below ground, or where it would be difficult to install any other type of pump below the minimum water level.

Oil-lubricated enclosed-line-shaft. Water lubricated open-line-shaft pump.

If the adequacy and reliability of the well is established and the entire installation conforms to the NFPA fire pump standard.

In order to provide for reliable operation of the fire-pump unit, submerge cue of the second impeller from the bottom of the pump-bowl assembly shall be not less than 10' below the pumping water level at 150% of rated capacity. The submergence must be increased by 1' for each 1000' of elevation the installation of above sea level.

In order to provide submergence for priming the elevation of the second impeller from the bottom of the pump-bowl assembly shall be such that it is below the lowest pumping water level in the open body of water supplying the pit. For pumps with rated-capacities of 2000 gpm or greater, additional submergence may be required to prevent the formation of vortices and/or prevent excessive cavitation. The required submergence shall be obtained from the pump manufacturer.

1. A motor head or right-angle gear drive. 2. A column pipe and discharge fitting. 3. An open or enclosed drive shaft. 4. A bowl assembly (containing the impellers). 5. A suction strainer.

Automatic air-release valve. Water-level detector.

A 1 1/2" or larger valve is required to vent air from the column and the discharge head upon the starting of a pump. This valve will also admit air to the column to dissipate the vacuum at that location there when the pump stops. It must be located at the highest point in the is charge line between the fire pump and the discharge check valve. A check valve mounted vertically in the inverted position is commonly used. Air will pass through the check valve, but water pressure will close its clapper.

Each well installation shall be equipped with a suitable water-level detector. If a permanently installed air-line is used, it shall be of corrosion-resistant metal, such as copper, and be strapped to the column pipe at ten foot intervals. A satisfactory method of determining the water level involves the use of an air-line of small pipe or tubing with known vertical length, a pressure gage, and an ordinary bicycle pump. The air-line pipe of known length extends beyond the lowest anticipated water level in the well.

Construct a lifting device such as a tripod or portable Derrick and use two sets of installing clamps over the open well or pump house. After the lifting device is in place, the alignment should be checked carefully with the well or wet pit to avoid any trouble when setting the pump.

Attach a set of clamps to the suction pipe on which the strainer has already been placed and lower it into the well or wet pit until the clamps rest on a block beside the well casing or on the pump foundation.

Attach clamps to the pump-stage assembly and bring it over the well casing. Install pump stages to suction pipe, etc., until each piece has been installed according with the manufacturer's instructions.

Motors mount directly on the top of the pump discharge base fitting. They sit in a vertical position and are bolted directly to the pump. No alignment check is necessary.

The position of the impellers in the pump unit is controlled by an adjustment of the coupling at the motor. This is referred to as the lateral adjustment. It must be made prior to start up. Failure to set this properly will cause immediate damage to the pump.

A right-angle gear drive is usually used to connect the vertical pump shaft to the horizontal Diesel engine shaft. The right-angle gear mounts on the pump discharge base in the same manner as an electric motor.

The lateral adjustment is the same as for an electric motor and must be done prior to start-up or damage to the pump will result.

The horizontal shaft of the gear is normally connected to the Diesel engine by a flexible shaft and universal joint arrangement. Alignment of these shafts differs from usual in that perfect alignment is not correct.

There should be misalignment of these shafts, as specified by the pump's manufacturer, to ensure proper operation.

The installations are equipped with a non-reverse ratchet. If a pump lacked such a ratchet, receding water in the pump columns when the driving power ceases would cause back-spin.

All field installed electrical connections, as well as the discharge piping from the pump must be checked. With the top drive coupling removed, the drive shaft must be centered in the top drive coupling for proper alignment, and the motor shall be operated for a moment to ensure that it rotates in the proper direction.

The impellers must be set for proper clearance. The top drive coupling shall then be reinstalled.

Than the pump shall be started and allowed to run. The operation is to be observed for vibration while running and also for any malfunctioning of the pump driver.

A bent pump or column shaft.

Impellers not properly set within the pump bowls.

Pump not hanging freely in the well.

Strain transmitted through the discharge piping.

By either a maintained low voltage of the electric service or an improper setting of impellers within the pump bowls.

The individual official, board, department, or agency established and authorized by a state, county, city, or other political subdivision created by law to administer and enforce the provision of the plumbing code. Also known as authority having jurisdiction.

Any audible or visible signal indicating existence of a fire or emergency requiring evacuation of occupants and response and emergency action on the part of the firefighting service.

The alarm device(s) by which fire and emergency signals are received.

A check valve, equipped with a signaling device, that will annunciate a remote alarm when a sprinkler head(s) is discharging.

The act of forming a straight line, either horizontal, vertical, or at a given angle.

Refers to an accredited laboratory or agency having capabilities for both the laboratory and field evaluation of backflow prevention assemblies or devices.

Abbreviation for the American society of heating, air conditioning and refrigerating engineers.

Abbreviation for American society of mechanical engineers.

The weight of air bearing down on the surface of the earth that causes pressure of about 14.7 lbs. to be exerted on each square inch at sea level.

The organization, office, or individual responsible for approving equipment, materials, installation, or procedure.

Abbreviation for American water works association?

A forming of partial vacuums in a swiftly moving liquid which causes the ottomh and wearing away of solid surfaces as a result of the collapse of these vacuums in the surrounding liquid.

Deterioration of a surface caused by cavitation (sadden formation and collapse of cavities in a liquid).

The force which tends to impel a thing or parts of a thing outward from a center of rotation.

A pump to force the circulation of liquid in a system.

An authoritative book of rules and regulations. Those regulations, subsequent amendments thereto, or any emergency rule or regulation which the administrative authority having jurisdiction may lawfully adopt.

A mechanical device for increasing the pressure of air or gas.

A gasket or washer in the form of a disk with a hole in its center and raised out peripheral edge.

Shaped like a cup, may be rubber or other material.

The administrative authority and any other law enforcement agency affected by any provision of a code, whether such agency is specifically named or not.

To detect or perceive something obscure or concealed?

Static discharge plus pressure need at the end of a pipe, less the frictional resistance of the discharge pipe.

The vertical distance from the outlet of a pump to the point at which liquid leaves a pipe.

A pump such as an air lift that raises or transfers a fluid by direct displacement with no transformation of energy due to the fluids motion into pressure.

A valve used with a dry-pipe sprinkler system where water is on one side of the valve and air is on the other side. When a sprinkler head's fusible link melts, releasing air from the system, this valve opens, allowing water to flow to the sprinkler head.

A vertical-shaft, turbine-type pump in a can (suction vessel) for installation in a pipeline to raise water pressure.

A pump in which the pressure is developed principally by the action of centrifugal force.

A single-suction pump having its suction nozzle on the opposite side of the casing from the stuffing box and having the face of the suction nozzle perpendicular to the longitudinal axis of the shaft.

UL-listed and/or FM-approved, low-flow, high-head pump for sprinkler systems not being supplied from a fire pump, the pump pressurizes the sprinkler system so that the loss of water supply pressure will not cause a false alarm.