Plumbing - Building Water Supply Part 3

1. Customer specifications, piping materials, joining techniques, support, insulation. 2. Code requirements. 3. Locations of components of the system. 4. Equipment size and pipe size requirements.

1. What is to be done and how it will be accomplished. 2. Math formulas. 3. Joining and support techniques. 4. How to sketch the system and its components. 5. Material characteristics. 6. Safety requirements.

Most individual water meters are located out side the building for accessibility. In some cases meter are located inside the building. You might also be required to install a back flow preventer in conjunction with the meter to protect the community water supply system from contamination.

1. Mains. 2. Mains branch lines. 3. Risers. 4. Minor branch lines. 5. Terminal points.

Convey the water to major branches and risers.

Carry the water from the distribution mains to special equipment, minor branches, and risers.

Transport water vertically at least the hight of one story ( one floor to another). Risers are supplied either by the main distribution line or a major branch. And they, in turn, supply either a major or minor branch line on a different foor.

Conveys the water from major branch lines or risers to the point of use called a terminal point.

No. Residential and remodeling work are examples of plumbing systems designed by a journeyworker, in a whole or in a part, without drawings or specifications. The basic elements of design are done mentally.

Locate the various parts of system.

Branch valves, unions, strainers, pressure Gage's, thermometers, and drain valves.

1. Pipe size to be used. 2. Kinds of pipe or tube materials to be used. 3. Location of mains, risers, and branches. 4. Location and types of sleeves, inserts, hangers, and supports. 5. Types, sizes, and location of fixtures and equipment. 6. Location of hangers, supports, and pipe connections to fixtures and equipment.

1. Select an area for storing pipe, fittings, etc. on the job. 2. Select an area for pipe cutting and assembly, and set up of equipment. 3. Determine the most logical procedure from design and layout information, such as pre assembly of parts and order of installation. 4. Make working drawing s or sketches when necessary. 5. Determine required pipe and fitting sizes.

1. Friction. 2. Velocity. 3. Rate of flow. 4. Pressure.

The water that is in contact with the walls of the pipeline moves at a lower velocity than the water in the center of the pipeline. The result of friction on flow is measured as pressure loss.

The rate at which liquids move through a piping system, measured in feet per second.

The volume of a moving fluid related to time. It is measured in gpm, gph, mgd (millions of gallon per day), cfs, cfm, cfd.

Force acting on a surface. It is usually measured in pounds per square inch psig.

1. Rate of use. 2. Fluctuation of pressure in the main due to rate of use by other customers. 3. Changes in pumping head. 4. Changes in elevation head. 5. Friction of water.

It can be referred to as head loss.

A column of water 1' high is equal to .433 psig.

Head pressure is 14x.433=6.06 psig. The pressure on the upper gage : P1-HP=50-6.06=43.94 psig.

Yes, the head pressure would be added to the upper gage pressure.

Neither the shape of a container, nor the area of its base affects the pressure (static) exerted by a column of water. The vertical height of the column is the factor that must be used.

Air flows into the faucet and forces the water ahead of it toward the point of lower pressure. If the faucet opening is submerged at the time of the negative pressure the result is back siphonage.

No. Pressure forces the water through the pipelines, but only that fast as that water is used. Velocity in a water supply system is the result of demand at the point of use, capacity of the supply system, and pressure.

FR = TF(volume)/T(time) = 5/1 = 5 gpm = 5/7.48 ~ 5/ 7.5 = .67 cfm.

One gallon of water contains 231 cubic inches , therefore: | 231x 5 = 1155 cu. in.

V(volume) = 1155/60 = 19.25 cu. in. per sec.

V = Vol/ A , where V - velocity, Vol - volume, A - area, A = .7854xDxD = .7854x1/2x1/2 = .196 = .2 sq. in. V = 19.25/ .2 = 8.02 fps.

The rate suggested for general service water is from 5 to10 fps. Velocities above the maximum may cause interior erosion of the piping, noise and vibration, below the minimum may cause stagnation of the water.

Yes, because 1. The pressure is less at the higher elevation, 2. Pressure is lost in the friction of the longer pipe run.

1. The available pressure from the water main. 2. Minimum and maximum pressures required at the fixtures. 3. Static pressure losses. (Head). 4. Individual and total fixtures dim and in gpm. 5. Flowing pressure (friction) losses. 6. Velocity limits.

1. Water closet 3 gpm. 2. Lavatory 3 gpm. 3. Bathtub 6 gpm. 4. Kitchen sink 4.5 gpm. 5. Laundry tub 5 gpm. Total demand 21.5 gpm.

No. The fixtures in a residence are not subject to continuous use. These fixtures are rated as intermittent use fixtures. Most codes have a minimum size service pipe which may take precedence over actual demand.

For extended period of time, as compared with most plumbing fixtures, water flows to or through the device at a constant rate of flow.

1. Lawn sprinkling systems. 2. Cooling water for refrigeration and air conditioning compressors. 3. Many type of industrial equipment. 4. Decorative displays. 5. Swimming pool filters. 6. Sill cocks.

A number of devices demanding water are in use at the same time.

The number of water supply fixture units (WSFU) of the fixture as compared to the flow of water to a lavatory which is assigned a value of 1 WSFU.

From 6 to 11 seconds.

1. Water supply fixture units. | 2. Fixture unit used for drainage.

The procedure used to determine the WSFU for each branch (H and C) is to rate each branch as demanding 3/4 of the WSFU assigned in the table. It help determine the size of water supply piping as well as water service pipelines when the demand weights of the various fixtures can be totaled and then converted to gpm.

The clear triangle, with its vertical and horizontal edges, enables the user to read the values at the edges of the graph without moving the device, and also read along the parallel line of the triangle to an intersection point on the graph.

Make separate list for the cold and hot water:: CW: 5 WC,FV 5x10 = 50 WSFU, 3 UR, FV 3x5 = 15WSFU, 4 L 3/4x(4x2) = 6 WSFU, 1 JSS 3/4x(1x4) = 3 WSFU, 1 DF 1x1 = 1, Total demand 75 WSFU. HW: 4 L 3/4x(4x2) = 6 WSFU, 1 JSS 3/4x(1x4) = 3 WSFU, Total demand 9 WSFU.

Use curve 1 of a graph if water closets are predominantly flush solves or curve 2 if they are tank type. The total demand of the 75 WSFU will be about 60 gpm. HW demand will be used to size the branch to the Water Heater and must be added to the total building demand. That CW demand for water heater branch 9 WSFU equals approximately 8 gpm. Total demand for building 50+8 = 68 gpm.

Both the compressor and the sill cock are continuous flow devices . Each gpm they use is added to the total gpm calculated for the fixtures. Table shows that 1 sill cock with 50' of hose equals 5 gpm. So the total cold water demand on the system is 8+5+21+60 = 94 gpm.

All bathrooms in private homes, apartments, hotels or motels rooms, and those for the convenience of an individual and his or her visitors in an office.

All uses for public. It includes all places where the public is served food or drink employee toilet rooms in all commercial, industrial, and institutional building, lobbies of buildings, places of recreation, passenger stations, automobile service stations, airports, public convenience stations, public parks, rest rooms, etc.

1st curve is used for public and 2nd for privet use in the graph of probable water supply demand (gpm). This curves have been developed from mathematical probability equations.

50 psi above normal working pressure but not less than 150 psi.

1".

By 5' of undisturbed or compacted earth.

A minimum of 12" above the top of the highest point of the sewer and the adequate pipe materials.

The water service pipe is sleeved to at least 5' horizontally from the sewer pipe centerline on both sides of such crossing.

It shall not be located in, under or above cesspools, septic tanks, septic tank drainage fields or seepage pits and shall be separated by a minimum of 10'.

1. Smooth copper pipe and tube - K, L, M copper and glass, plastic pipes. 2. Fairly smooth pipe - new galvanized or steel pipe. 3. Fairly rough pipe - new cast iron and used galvanized steel piping up to 10 years old. 4. Rough pipe - old cast iron and steel water pipe.

1. The vertical lines on the flow chart represent the friction loss in head, measured in pounds per square inch gage per 100' of length. 2. The lines which run diagonally from lower left to upper right represent the nominal inside diameter of the pipe. 3. The lines which run from lower right to upper left, represent the velocity in fps. 4. The horizontal lines represent flow in gpm.

``` FL = PxL/100: FL- friction loss, P-pressure in psig, L-the length of pipe in feet, 100- hundred feet. ```

9 psig is the friction loss by chart for 100' of pipe. For 20' it will be: 9/5= 1.8 psig.

Approximately 7.75 ft. per second.

Using table find the point at which 15 psig and 40 gpm intersect.this point is just above 10 fps, so it is within the velocity limits. That point is just below the 1 1/4" line, so 1 1/4" copper pipe must be used.

A liner value (length in feet) is assigned to each fitting, which is then added to the length of the pipe run.

Fitting friction loss:

3-90* elbows: 3x1.5=4.5'

2-45* elbows: 2x1.0=2.0'

1-Tee: 0.45=0.45'

1-Gate valve: .3'

All together: 7.25'

Section of pipe run: 25'.

Friction loss: 7.25+25.00=32.25'.

Pressure loss for the flow of 25 gpm 1" line is approximately 13 psig per 100' of pipe run.

The pressure loss for our section will be: 32.25/100x13 = 4.19 psig.

The flow pressure is measured on the inlet side of the wide open faucet (upstream).

The minimum residual pressure is 8 psig.

Static pressure (no flow) ~ residual pressure (flowing) x 2.

Roof tanks.

Hydro pneumatic tanks.

Multistage pumps.

Variable speed pumps.

H = P/P1ft = 8/0.433 = 18.5'.

If water closets with flush valves are used:

H = 15/0.433 = 34.6'.

Add the pressure losses due to friction for pipe, fittings, and valves and the outlet losses from the tank.

When the water level in the tank drops to a predetermined level, a control (either a float assembly or water sensitive switch) activates the pump to re supply the tank.

Another switch located just below the tank overflow, shut off the power to the pump.

A vertical pipe that runs from the lowest floor of a building to above the roof and feeds water to fire hose cabinets, fire hose outlets, and fire sprinkler systems within the building or on its roof.

An outside screw and yoke valve.

A double fire hose connection that is installed on the outside of a building. It is used by the fire department to pump or supply water to fire protection systems inside of a building.

1. Horses leading to street fire hydrants. | 2. Hoses to fire pumping apparatus.

Yes. Suction houses from fire pumpers may also draw water from rivers, lakes, ponds, irrigation ditches, etc.

1. An elevated roof tank completely separated from the domestic water system. 2. A reduced pressure zone back flow preventer can be placed in the location of the crack valve on the down feed domestic supply from the tank.

Firefighters may connect hoses to fight a roof fire regardless of its location.

A vessel which contains approximately two-thirds water and one-third air.

Pressure is sensed by the switches in the control panel through the small pipeline that is run from top of tank. When the desired pressure is reached, normally 60 to 80 psig, the pressure switch opens and shuts off the pump. At a minimum pressure, normally between 30 to 50 psig, the pressure switch activates the pump.

The fire standpipes can be fed from the pipeline serving the fixtures.

The smaller pump is capable of supplying minimum demands. If the demand is too great for the small pump, the pressure will continue to drop until the controller activates the larger pump to compensate for the pressure loss.

Pressure-sensitive switches control the amount of power delivered to the motor. As the pressure drops due to increased demand, the next switch calls for more power. When this increased power is delivered to the motor, the speed of the motor increases and more head pressure from the pump is delivered to the system.

1. Water hammer. 2. Vibration. 3. Rushing noises.

The shock, and accompanying banging noise, created when a valve or faucet is suddenly closed against water flow. It is caused by the abrupt alteration in the flowing of the water. The shock bounces back and forth along the pipe and may reverse itself several times from a single quick stoppage of flow.

Loosen pipe hangers, damaged parts of valves, faucets, or the water meter, loosen pipe joints or burst the piping. Any ordinary pressure gage can be ruined by water hammer.

1. Mechanical shock absorbers in appropriate locations in the system. 2. Adequately sized air chambers at the top of all risers each branch feeding groups of fixtures or equipment . 3. Provide both mechanical devices and air chambers.

The shock and reversed flow are absorbed by an expandable bellows or a heavy- duty flexible tube (installed inside a protection metal cap).

All types of solenoid valves, spring -action faucets, self-closing faucets, icily-closing gate valves, and high-speed motor-operated valves.

The air trapped in the upper part of an air chamber is compressed by the shock wave of water hammer and absorbs the kinetic energy of the shock wave.

On horizontal piping, it is connected by means of a side outlet tee, on risers and water supply branches, it is installed at the top.

1. Gate valve. 2. Petcock at base. 3. Petcock at cap.

1. Not less in diameter than the pipe supply line served. 2. Not less than 18" in length. 3. If it is close to a quick-closing valve, the air chamber body should be at least one pipe size larger than the pipe served and its length should be increased by 18*. 4. The connecting nipples and the shutoff valve should be not less than one-half the diameter of the supply pipe.

By using hangers and anchors that are installed or covered with rubber, plastic, or other sound-deadening materials. If the noise is caused by movement of pipe against a structural member, such as a joist, wall, or column, insulation should be placed between the pipe and the structural member.

The condition that develops in fittings, valves, and at sudden enlargements when water at high velocity makes an abrupt change in direction.

1. Increasing the pipe size. 2. Using fewer fittings. 3. Using reducers instead of bushings. 4. Changing the type of valve for better quality.

1. Specific use. 2. State, local or provincial code requirements. 3. Chemistry of the water. 4. Amount of money to the spent.

The water contain different minerals and dissolved gases. The gases can make the water corrosive or the minerals can build up on metal surfaces. Treating the water supply, selecting materials that resist oxidation, using corrosion resistant glazes or linings and using a sacrificial element are methods used to slow down the corrosion process.

1. Where the service enter the building . 2. Where pipe spaces, pipe chases, and partitions are located. 3. Where pipe is to run above ceilings and how much space are available. 4. Where other mechanical work is to be located.

A riser diagram or an isometric drawing.

1. Consider accessibility to unloading and assembly areas. 2. Select a site out of the way of job progress. 3. Discuss your selected site with the job superintendent for unknown problems or other plans for the area.

1. A power source. 2. Nearness to the storage area. 3. Protection from weather. 4. Enough space.