Plumbing - Building Water Supply Part 6

They are applied to high pressure and, at times, in combination with high temperatures. Turbine pumps having top centerline discharge are self-venting and have the ability to handle vapors without vapor lock. This characteristic allows handling of boiling liquids and liquefied gasses at suction heads slightly over the vapor pressure.

Open.

Semi-open with plate on one side (web).

Enclosed with both sides covered and shroud on the end of the blades.

Open end suction.

Semi-enclosed end suction.

Enclosed end-suction.

Enclosed double-suction.

Paper stock.

The impellers must begin revolving at the proper speed and the pump must first be primed.

Many shallow well installations have foot valves at the end of the suction pipe.

By use of a deep well pumps:

A submersible.

A reciprocating.

A jet pump.

It, including the motor, is completely immersed within the liquid it is pumping and, therefore, the impeller is always filled with liquid.

If allowed to run dry for any significant length of time because pumped liquid lubricates and cools the submersible pump.

Sucker rod pumps.

Stroke pumps.

Working heads.

Foot valve.

Cylinder.

Plunger.

Drop pipe.

Pump rod (wood rod and wood rod coupling).

Discharge.

Air-pump.

A V-belt driven gear box.

Electric motor.

The up and down movement of the wooden rods makes the upper and lower plunger and check valve open and close simultaneously allowing water to enter the drop pipe. Water is forced up through the drop pipe the discharge outlet on the working head.

1. Cam-and-piston. 2. External-gear. 3. Internal-gear. 4. Two-lobe. 5. Three lobe. 6. Four-lobe. 7. Single-screw. 8. Two-screw. 9. Three-screw. 10. Swinging-vane. 11. Sliding-vane. 12. Shuttle-block. 13. Universal-joint. 14. Eccentric in flexible chamber. 15. Flexible tube.

The centrifugal pump sends apportion of its discharge to the jet fitting where a partial vacuum is formed by the high velocity fluid discharge from the jet nozzle. After the water passes through restriction into the expanding Venturi fitting the velocity decreases with a corresponding increase in pressure. This increase in pressure is used to push the water to within the limits of the centrifugal pump suction lift.

Each stage is essentially a separate pump, they are located in the same housing and the impellers are attached to the same shaft. Two or more stages may be found in a single housing.

The liquid enter the pump parallel to the shaft or axis, pass through the impeller axial lay and leave through the discharge still in an axial direction. The pressure of the liquid was increased by the propelling or lifting effect of the vanes of the impeller on the liquid.

Shaft.

Propeller.

Suction bell.

Discharge bowl.

Axial flow. Mixed flow.

The liquid enter the impeller at its periphery opposite the suction opening of the pump. The short impeller vane causes the liquid to be thrown away from the center of rotation. The channel reverses this flow and again the liquid is fed into the impeller vane farther around the channel in the direction of rotation. The liquid flows through the pump in a spiral pattern continuously receiving energy and building up pressure toward discharge of the pump.

Fire hose valve.

Low and level alarms..

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Use of air chambers is prohibited by NYC code.

On combustible floors.

Any controls or auxiliary equipment, such as pumps, for the system should be easily reachable for setting and maintenance. Most large indirect systems have coils and an inspection manhole in the tank. The coil are generally long. Positioning must take into consideration removal of the coils and access to the inspection manhole.

1. Thermometers. 2. Circulating pump. 3. Isolating valves and drain valves. 4. Declining tees. 5. Operating controls. 6. Water hammer arresters.

At the inlet of a heater, and at the outlet, provide an indication of the satisfactory operation of the heater. A deviation from the usual operating temperatures is indicative of a malfunction of the equipment (or that recantation of a thermometer is required.

To obtain 1 appropriate heat transfer without an excessive temperature rise and 2 the rated capacity of the heater, water must be forced through the heating coil by a circulation pump that is correctly selected for its specific application. A flow switch prevents firing of the heater unless the circulation pumps in operation and water is flowing through the heater.

Isolate the flow of water to each heater or to permit any specific part or all of the system to be drained for repair or maintenance purposes.

They are provided at the entry and outlet of a heater to permit the temporary installation of deliming equipment periodically.

Containing less than 1 grain per gallon of dissolved calcium and magnesium hardness minerals (17.1 parts per million).

Include devices that turn a heat source on and off automatically and devices that control the valves which admit hot water to a heat exchanger. Usually an immersion-type aquastat (a sensor immersed in the water being heated) that controls 1 electric heating elements or 2 gas or oil burners; the heating is turned on when the temperature of the water falls to a set temperature; the heating is turned off when the temperature rises to a second set temperature. Appropriate secondary safety devices must be included that are set slightly higher than the operating controls and will shutoff the energy supply ( electricity, gas, or oil) should the operating controls fail to function.

Absorb sudden increase in pressure in the pipe line as a result of a sudden change in the rate of water flow or an abrupt stop of the water flow.

1. A water-mixing (tempering) valve. 2. Solar tempering tanks. 3. Pre-heaters. 4. Heat reclaimers (waste hot water).

The incoming cold water is heated by solar panels through the use of a heat exchanger. In cooler less sunny climates, the tempering tank is the secondary source of heat and the storage heaterbisbthebptimary source. In sunny, warm climates, the tempering tank is the primary source of water heating and the storage heater is a backup.

A. Heat exchanger tank: 1. Large surface area heat exchanger. 2. Fill valve line. 3. Drain valve. 4. Thermometer. 5. Level gage. 6. Heat sensor. 7. Line to heat collectors. 8. Line from heat collectors. B. Line to heat collector: 1. Thermometer. 2. Gate valve. 3. Strainer. 4. Pump. 5. Globe valve. 6. Tee to collector. 7. Drain valve. C. Line from collector: 1. Air vent. 2. Vacuum breaker. D. Differential thermostat electric connections: 1. 115 volt AC. 2. Collector heat sensor. 3. Exchanger heat sensor. 4. Pump. E. line to water heater from exchanger: 1. Insolation valve. 2. Bypass Tee. F. Line to heat exchanger: 1. Gate valve of cold water supply. 2. Tee to mixing valve. 3. Tee to bypass valve. 4. Heat exchanger insulation valve. G. Water heater: 1. Cold water line with Tee from heat exchanger and cold water bypass valve and dip tube. 2. Hot water line to mixing valve. 3. Auxiliary electric elements. 4. Temperature and pressure relief valve. 5. Drain valve. H. Mixing valve connections: 1. Line from water heater. 2. Line from cold water supply. 3. Line to domestic hot water system.

It is simply a water heater of adequate capacity installed in series with the incoming water line ahead of the primary heater. In colder climates, where surface water supply temperatures drop sharply in winter, there is often a need for increased water heating capacity. In such instances, the pre-heater is put into operation until warmer incoming water temperatures again prevail.

Warm air within a building is forced through a heat pump; then the air is exhausted to the outdoors. The heated water is then fed to a reservoir equipped with an auxiliary electric water heater.

A device that transfers heat from a cooler space or reservoir to a warmer one.

Warm ambient air is drawn into the top of the unit through a filter. The evaporator extracts heat from this air and transfers it to the refrigerant. The compressor compresses the hot refrigerant gas and concentrates the hot heat in the refrigerant. The heat is then transferred from the refrigerant by a heat exchanger to the water to be heated.

A. The heat is gathered as follows: 1. Air containing waste heat enters through a filter. 2. The evaporator extracts heat from the air and transfer it to the refrigerant system. 3. The compressor concentrates heat in the refrigerant system. 4. Heat is transferred by the heat exchanger from the refrigerant to the water. B. The water is heated as follow: 5. Cold water enter the tank. 6. Water is drawn from the bottom of the tank into the heat exchanger in the heat pump unit, where it is heated. 7. Heated water is returned to the tank through an inlet dip tube. 8. The heated water is drawn from the top of the tank where it has risen after having returned from the heat pump unit.

Natural, mixed, and manufacture gases are utility (underground) types. Propane and butane or a mixture it both are liquefied petroleum gases, commonly called LP gas which are transported to the point of use.

The gases that you will encounter are odorized to aid in detecting leaks. Natural, mixed, and manufactured gases are stored and delivered in a gaseous state. If the gas should escape prior to burning , it will rise into the air of a room and possibly escape to the atmosphere. Thus, these gases are lighter than air, and leakage can be detected by smell.

LP gas is heavier than air, and if it escapes unburned, it will accumulate in the lowest areas of the space. You would, therefore, have to be at the level of the vapor to detect leakage by smell.

Natural gas. Propane, a heavier-than-air gas, is the second most popular fuel. Butane has a slightly higher heating value, per cubic foot, than propane. However propane is popular because its low boiling point permit it to be used in climates where the temperature drops below freezing.

The release of heat energy from fuel gas and is a result of rapid oxidation or burning.

To burner:

1. Gas.

2. Oxygen in primary air.

3. Oxygen in secondary air.

Products:

1. Light and heat.

2. Carbon dioxide.

3. Water vapor.

By incomplete combustion of the gas being burned:

Improper primary air adjustment.

Lack of combustion air.

Gas input in excess of the water heater rating and flame impingement.

The flame does not have room for complete combustion. If an object is held too close to a flame, the flame will produce heat but will not have sufficient combustion air. Flame impingement reduces the flame temperature to a point below that required for complete combustion.

The weight per cu. ft. Of hot combustion gases is less than that of the surrounding cooler air. The resulting current of air leads to a natural exhausting of the gases from the combustion chamber. Down-drafts will blow the combustion products back into the flue pipe.

The low temperature of the incoming water causes condensation on the heat exchange surfaces of the water heater. Condensation in the flue results from problems in the chimney.

The flow can be affected and allow water vapor to condense if:

The flue pipe has excessive turns or is unusually long,

The chimney absorbs too much heat.

A corrosive condition in the flue and hot water heater or or become a nuisance by dripping on the floor.

Where a back-draft or an insufficient draft condition cannot be avoided, a forced vent system may be needed.

If a cold chimney is the cause, double -wall vent material along with a flue exhauster ( draft inducer) can be used to maintain the heat content of the combustion gases.

A draft hood, installed directly on the heater flue, prevents sudden changes in draft from affecting flame characteristics in the combustion chamber.

The hood also permits the combustion products to escape when there is no draft, or a stoppage.

Draft (products of combustion) draws air directly into the flue pipe through the draft hood.

When checking, be sure the chimney is hot or that the heater has operated for 15 minutes. A test for flue gas (combustion products) spillage can be made with a lighted match held at the lower edge of the skirt ring. When the flue is operating correctly, the flame is drawn into the draft hood and continues to burn. If the match flame is blown away or is extinguished by spilling flue gases, the vent is not operating correctly.

Sooting and damage to the water heater and may be hazardous to life.

For gas: draft diverter, for oil: draft regulator or barometric damper.

No. The draft hood as furnished is apart of the appliance and as such must be attached directly to a gas fired water heater. You cannot locate the draft hood in another room or above a ceiling. Alternation of the design or extending or shortening the height or distance of the hood from the heater is also forbidden.

The draft regulator should be located in the flue pipe close to the heater.

Combustion.

Ventilation.

Draft hood dilution air.

1. Natural gas - 10 cu. ft. 2. Propane - 24 cu. ft. 3. Oil - 40 cu. ft.

Prevent the surrounding temperature from rising due to the normal operation of the heater.

Yes, in the case of gas or other flame operated water heaters. Exhaust fans, ventilation systems, clothes dryers, or fireplaces may create conditions requiring special attention. It is possible for a ventilation system to draw outside air down the chimney while the water heater is trying to send up the products of combustion.

Generally, if the chimney cannot safely vent the heater, a draft inducer may be installed in the vent pipe between the heater and the chimney.

Air that has considerable dirt or lint particles. Air that contains the vapors of chemicals in the chlorine family.

Clog air passages and cause improper combustion and soothing of heat exchange surfaces. Try to avoid locating the equipment in a dirty area.

When the burner flame heats combustion air containing chlorine fumes, the resulting hydrochloride acid attacks the heat exchange surfaces of the appliance.

Swimming pool, beauty shop, and dry cleaner installations are the most common trouble spots.

Locating the heater in a separate building or enclosure.

With internal (immersion) elements - transfer heat directly into the water at the point where they project into the tank.

With external (wraparound) elements - offer the advantage of element replacement without draining water but the heat from the elements must be transferred through the tank wall.

3,415 Btu.

Electric water heaters are generally considered to be 100% thermal efficient. To calculate the amount of electricity required to heat the water for 1 hr., divide heat output by 3.415 Btu/watt.

Voltage is the force or pressure that causes electrons to flow through a conductor as electric current. The unit used in measuring the pressure is the volt.

The higher voltage best serves electric water heaters although 120 volt elements are available. High voltage, which is generally used in commercial and industrial applications, ranges from208to440 volts.

Nickel-chromium wire with high resistance characteristics slows the flow of electricity and produce the heat that is transferred from the electrical insulation and element sheath into the water.

A measure of the power that is released as heat in the heating element: W= IxE.

I = W/E = 4000/236 = 16.9 A.

| A fuse or circuit breaker with a rating of 20 amperes is needed.

Just as higher or lower water pressure causes more or less water to flow through a given size of pipe, a change of electrical pressure (voltage) will cause a similar increase in heating ability.

Water that forms scale (hard water) or contains suspended matter,

Aggressive water that attacks metals (water that is highly corrosive).

Incoming water temperature,

Water pressure.

1. Sputtering at the hot water faucet, 2. Specks of magnesium suspended in the hot water, 3. Noisy heater operation (undergirded heaters only).

Sulphur-bearing water can react with the magnesium anode to form magnesium sulphide, which is highly odorous.

1. Turn the thermostat to its coldest setting to see if the burner goes off. 2. Turn the thermostat back to a normal setting to see if the burner goes on when the thermostat calls for heat. 3. For gas fired heaters with the main fuel control in the full open position, extinguish the pilot. If the pilot safety is working, no fuel should be able to get the burner after the pilot goes into a fail/safe position. 4. Lift the lever on the combination temperature and pressure relief valve to make certain it will open and pass water to relieve pressure.

To prevent most water heater accidents like tap water scalds.

Scald protection and thermal shock. Scalds from hot water are the cause of thermal shock which sometimes results in personal injury from falls and other injuries as individuals react to the sudden change.

1. The mixing or diverting valves. | 2. The mixer of the thermostatic type with a liquid filled thermal motor.

1. The water flow is cut-off if the thermostat's liquid motor fails. 2. It responds automatically if the hot water supply is interrupted, or if the temperature changes. 3. It guards against scalding if the cold water supply is interrupted.

1. Line from hot storage tank with heat trap (27" drop) to the hot side of valve. 2. From cold water supply through the valve to Tee of storage tank and tempering valve. 3. From Tee of cold water supply to tempering valve cold side with check valve and recirculation line Tee. 4. From cold water supply Tee to storage tank through check valve and recirculation line Tee. 5. From circulation line to Tee of tempering valve cold water side and cold water supply to storage tank with aquastat temperature setting, shutoff valve, recirculating pump. 6. From Tee of recirculation line to Tee of tempering valve clod water side through check valve. 7. From recirculation Tee to Tee of storage tank cold water supply with balancing valve and check valve.

A separate recirculating loop and pump are required to return high temperature hot water to the water heater.

If is not possible to install the mixing valve below the hot water tank or heater.

Flush the system thoroughly.

Make sure the hot water supply is heated to normal temperature.

Close and tag all fixtures to ensure they are not used during this procedure.

Turn off the recirculating pump.

Creat a draw on the system greater than the minimum flow rating of the mixing valve.

Allow water to flow through the mixing valve until the water temperature is stable. If necessary, readjust the mixing valve.

One the temperature is set, start the recirculating pump and allow the system to reach the set temperature.

Measure the water temperature at the return pump and adjust the aquastat to shutoff the pump souls the return water exceed the set point 2F. Set the low limit switch to restart the return pump when return water temperature drops 5F below the set temperature.

Set the balancing valve in the full open position.

Shutoff all fixtures and ensure there is no draw on the system. The cold inlet to the mixing valve should be warm.

Allow the system to run in this condition for at least 30 minutes.

In some cases, an increase in water temperature may occur during a no draw period. If this occurs, slowly close the balancing valve until the water temperature is back to the original set temperature.

A well designed recirculation system will not only optimize the performance of the mixing valves, it will also save money and energy. They may be required by state, local or provincial codes, especially when the length of the hot water piping exceeds 100'.

Steam input to water heater tank with spans valve on it.

Cold water supply to water heater with check valve, Tee from low temperature hot water return, Tee to CW side of mixing valve, check valve, Tee from high temperature hot water return, Tee to expansion tank.

High temperature hot water loop from water heater with Tee of mixing valve, Tee of fixtures, high temperature hot water return connections, aquastat and controlled by it pump, Tee of CW to water heater.

Low temperature hot water loop from HTHW Tee with heat trap, by-pass Tee, check stop of mixing valve, thermostatic mixing valve, insulation ball valve, supply pressure gauge, PRV, outlet pressure gauge, by-pass Tee, pressure gauge, sensor of temperature sensing device that control solenoid valve, shock absorber, solenoid valve, fixture connections, LTHW return connections, aquastat for pump, pump, check valve, CW supply Tee.

By-pass line from HTHW to LTHW Tees with checkstop of manual mixing valve, manual mixing valve, insulation ball valve.

Cold water line from supply to mixing valves with by-pass Tee, check stops of mixing valves.

It is the simplest way to avoid needless service calls, dissatisfaction, personal injury and unnecessary lawsuits.

This is done to help the pipe trades constructor become a proactive force in consumer safety, especially in the areas of flammable vapor fires and tap water scald burns.

Professional video

covering the dual hazards of flammable vapors and tap water scald burns.

A safety checklist.

A danger label, to be reviewed with building owners and affixed to water heaters installed before the label becomes mandatory.

A size right for safety brochure, explaining the importance of moderate temperature setting on water heaters and effect of such settings on unit sizing.

Since 1989 every hot water heater shipped by a U.S. manufactures has a danger label affixed to it.

Also supply of these labels available free to all pipe trades contractors.

The checklist should include a section where the contractor or journeyworker can document the temperature setting of the water heater thermostat. It must provide a place for the building owner to sign, acknowledging that he or she has reviewed and understands the precautions noted on the checklist.

Discuss each item on the list with the customer.

Indicate the approximate full-on hot water temperature at the nearest faucet.

Fill out your name and the customer's name and address at the bottom of the checklist.

Ask the customer to sign at the bottom.

File one copy of the checklist and ask the customer to keep another copy for future review.

150F water scalds in just 1/2second. 140F in1second.

But 120*F in 4 four minutes.

To start a bath, turn on the cold water first, then the hot. When the tub is filled, turn off hot first.

Never permit a child to turn on the bath water. Always check the temperature of the water with your hand before immersing a child in a bathtub which contains hot water. Fill around the entire tub for hot spots.

Never leave a child alone in the tub or shower.

Use combination valves that have both pressure-balancing and thermostatic features.

Anti-scald devices are temperature control devices to limit discharge temperature to 120*F in the case of domestic hot water.

Thermal shock devices utilize pressure balancing to prevent rapid temperature fluctuations in water temperature.

C. Wells.