There are a number of patented nipple chucks on the market, but as they are not always at hand the above method is resorted to and serves every purpose.
LONG SCREWS.--To cut a long screw which comes in use frequently on vent pipe work, a piece of pipe 12 inches long is taken and a regular length thread is cut on one end, and a thread 4 inches long is cut on the other end. Then a coupling is cut while screwed on a pipe, so that a lock nut about 1/2 inch wide is made. The description and use of these long screws will come under screw pipe venting.
Now that the proper use of the tools has been explained, we will proceed with the exercise according to the sketch. With a length of pipe in the vise and the 1-inch dies in the stock, run over the thread on the pipe. Note that all the measurements are center to center. Screw an elbow on the pipe and measure off the first length, which we will take as 12 inches center to center. Place the rule on the pipe with one end of it at the center of the opening of the elbow just screwed on. Mark 12 inches off on the pipe. This mark represents the center of another ell. Now take another ell and hold the center of one outlet on this mark. It will readily be seen that to have the measurement come right, the pipe must be cut off at a point where it will make up tight when screwed into the ell.
Therefore, about 1 inch will have to be cut off, making the pipe 1 inch shorter than where it was first marked. Cut the pipe, and before taking it out of the vise make a thread on the pipe still in the vise. After the thread is cut, take the reamer and ream out the burr that is on the inside of the pipe caused by the pipe cutter.
An elbow can be screwed on this pipe. The next measurement is marked off as explained, the pipe cut, then the piece in the vise threaded and reamed. The measurements must be accurate and the dies should be adjusted to cut all threads the same depth. When the measurements are all out, there should be seven pieces of pipe, each piece having one thread. Now the threads on the other end can be cut except the 12 inch piece that screws into the right and left coupling. This thread is a left-handed thread and must be cut with the left dies. Change the dies now to the 1-inch left dies; turn the stock in the opposite direction of the right-hand thread, and the dies will cut the left thread. The pipe and the fittings can easily be put together as shown in the sketch by following the center to center measurements. The right and left coupling is the only fitting that will cause the beginner trouble. A right and left coupling can be used only when there is sufficient _give_ to the pipe, that is, the two ends of the pipe to be coupled together are only 1/2 inch apart. To get the coupling in place to start the threads, the pipe must spread apart at least 2 inches. If the pipe cannot be spread that much, a right and left coupling cannot be used. The proper way to make up a right and left coupling is as follows:
[Ill.u.s.tration: FIG. 69.--_F_ reads center of ell to end, _C_ reads center of ell to center of valve, _D_ reads center of valve to center of T, _E_ reads center of T to center of ell.]
Screw home the coupling on the right thread. Mark with a piece of chalk on the coupling and the pipe showing a point on each where the coupling makes tight. Take off the coupling and count the turns and make note of the number. Now do the same on the left thread and make a note of the number of threads. If the left thread has six turns and the right has four and one-half, then to insure that the left thread will be tight when the right thread is, the coupling must be put on the left thread one and one-half turns before it is started on the right thread. Now with four and one-half turns, the right and the left threads will both be tight.
A little thought and practice will make this connection clear. If all the measurements in this exercise are not cut accurately, the right and left coupling will not go together.
CHAPTER XIII
COLD-WATER SUPPLY. TEST
The supplying of cold water to buildings and then piping it to the various fixtures makes a very interesting study. We have gone over the methods of laying and piping for the house service pipe. We will go over the different systems now employed to supply the water, quickly.
UNDERGROUND WATER.--In thinly populated districts the well is still employed to supply water to the building. The water is brought to the surface by means of a large bucket or by means of a pump. A well point can be driven into the ground until water is reached and then the water can be brought to the surface by means of a pump operated by hand or by power. The water can be forced to a tank that is open and elevated, or forced into a tank that is closed and put under pressure. From either tank the water will flow to any desired outlets. A windmill can be employed to furnish power to operate the pump. Water supply that is received directly from underground is by far the best to use. A cesspool or outhouse must not be allowed on the premises with a well, otherwise the well will be contaminated and unfit for domestic use. An open well is not as sanitary as a driven well, as the surface water and leaves, etc., get into it and decay and pollute the water, and soon make it unfit for domestic use.
STREAMS AND BROOKS.--The brooks and streams furnish a good source of supply for water to a building or community of buildings. The writer recently worked on a system of piping that supplied 15 or 20 buildings. The water supply came from a brook that was higher than the houses. Each house had a separate pipe leading down from the brook into a tank from which the house was piped. The owner of the brook applied business ethics to the privileges of taking water from it. He had a scale of prices, and the highest-priced location was an inch or so below the bed of the brook, the next price was level with the bottom, the next cheaper 2 inches above the bottom.
As the surface was reached, the privilege cost less. In the dry time of the year those at the bottom of the brook always had water while those at the top location had to wait for the water to rise, and had to do without water during the dry time. Where the stream is on a lower level than the building a hydraulic ram can be used.
RIVERS AND LAKES.--Rivers and lakes make an abundant supply for water systems. A sluggish-moving river is bad, also a river that is used for carrying off the sewage of a town. Special provision is now made for the using of water that is polluted. A lake that is supplied by springs is by far the best source of supply. The water is pumped from the river or lake into a reservoir and then flows by gravity into mains and from the mains into the buildings. The water should always be filtered before it is allowed to enter the distributing mains.
WATER PRESSURE.--Pressure at a fixture or outlet so that the water will flow is generally obtained by the force of gravity. When this method is not sufficient, a pneumatic system is employed. This method is employed to force the water to the top floors or to supply the whole building in high structures. The pneumatic system requires a pump, an air-tight tank, and pipes to the various outlets. The water pumped into the air-tight tank will occupy part of the s.p.a.ce generally occupied by the air. The air cannot escape and is, therefore, compressed. Continued pumping will compress the air until the limit of the apparatus is reached. If a valve or faucet that is connected with the tank is opened, the air will expand and force the water out of the opening. This explains in a general way the operation of a pneumatic water-supply system. Water can be pumped into this air-tight tank from a well, cistern, river, lake, or from the city supply mains.
[Ill.u.s.tration: FIG. 70.--"Banjo."]
PIPING.--From the service pipe on which there has been placed a shut-off, a line of piping, full size, is run through the bas.e.m.e.nt, overhead to a convenient place, perhaps to a part.i.tion in the center of the cellar. The pipe is brought down and connected into the end of a header. This header or banjo is made of Ts placed 4 inches center to center. From each T a line of pipe is run to each isolated fixture or set of fixtures (see Fig. 70). A stop and waste c.o.c.k is placed on each line at such a point that all stop c.o.c.ks will come in a row near the header. A small pipe is run from the waste of each stop and discharged into a larger pipe which connects with a sink. This way of running pipes while it is expensive makes a very neat and good job. Each stop c.o.c.k has a tag on it stating explicitly what it controls. If the building is a large one a number of these panelled headers are used. A less expensive way to run this pipe is to branch off from the main at points where the branch pipe will be as short as possible and use as few fittings as possible. Stop and waste c.o.c.ks are then placed on each branch near the main.
All pipe must follow the direct line of fitting with which it is connected. The line of pipe should be perfectly straight. If it seems necessary to bend the pipe to get around an obstacle, then good judgment has not been used in placing the fitting into which the pipe is screwed. The fitting should be re-located so that the pipe can be run without bending. To have true alignment of pipes the whole job or section of the job must be drawn out on paper first and any obstacles noted and avoided before the piping is cut.
This not only saves time but it is also the forerunner of a good job. When getting measurements for piping the same rule or tape should be used to get out the pipe as was used to get the measurements.
The water main and branches that run through the bas.e.m.e.nt of a building are generally hung on the ceiling. Rough hangers of wood, rope, or wire are usually used to hold the pipe in place at first, then neat and strong adjustable hangers are placed every 8 feet apart. There are in use too many kinds of hangers to explain or describe them here. The essential point of all good hangers is to have them strong, neat, and so made that perfect alignment of the pipe can be had. The hangers should be so placed that no strain will come on the fitting or the valves. A hanger should be placed near each side of unions so that when the union is taken apart neither side of the pipe will drop and bend. Hooks and straps should be used to hold vertical pipes rigid and in position. A vertical pipe should be so held in place that its weight will come on the hooks and straps that hold it rather than on the horizontal pipe into which it connects. Where there are six or eight horizontal lines of pipes close together, a separate hanger for each pipe makes a rather c.u.mbersome job and it consumes considerable time to install them properly. A hanger having one support run under all the pipes will allow s.p.a.ce for proper alignment and adjustment for drainage. Allowance must be made on all lines of pipe for drainage. When a building is vacant during cold weather, the water is drawn off; therefore, the pipes should have a pitch to certain points where the pipes can be opened and the entire system drained of water.
KINDS OF PIPE.--The kind of pipe that is used for cold-water supply depends on and varies according to the kind of water, the kind of earth through which it runs, and the construction of the building.
Wrought iron, steel, lead, bra.s.s, tin-lined bra.s.s, are in use.
The supply pipe to every fixture should have a stop on it directly under the fixture. This will allow the water to be shut off for repairs to the faucet without stopping the supply of other fixtures.
The making of perfect threads on pipe is an important matter, especially on water pipes. If the pipe and the dies were perfect, and the mechanic used sufficient oil in cutting, and the fittings were perfectly tapped to correspond to the dies used on the pipe, of course a perfect union between pipe and fitting would result and the joint would be found to be perfect on s.c.r.e.w.i.n.g the pipe home.
As all the above conditions are not found on the job, threads are made tight by the use of red or white lead and oil. The lead is put on the thread and when the thread is made up the lead will have been forced into any imperfection that may be in the threads and the joint will then be water-tight. White lead and oil should be used on nickel-plated pipe as other pipe compounds are too conspicuous and look badly. A pipe compound should be used with discretion, for if too much is put on a burr of it will collect in the bore of the pipe and reduce it considerably. This is not tolerated, so only a small amount is used. Water pipes should be run in accessible places, making it possible to get at them in case of trouble. In climates that have freezing weather water pipes should not be run in outside part.i.tions. If it is found absolutely necessary to do so, as in the case of buildings which have no inside part.i.tions on the first floor, the pipe should be properly covered and protected. The different methods of covering pipes are described in Chapter XV.
CHAPTER XIV
HOT-WATER HEATERS. INSTANTANEOUS COIL AND STORAGE TANKS. RETURN CIRCULATION, HOT-WATER LINES AND EXPANSION
The problem of supplying hot water to plumbing fixtures is one that has required years of study. Each job today demands considerable thought to make it a perfect and satisfactory hot-water system. We will find installations today where the water is red from rust, where there is water pounding and cracking. There are also jobs where the fixtures get practically no hot water. As each job or individual building has its own peculiar conditions, they must be solved by the designer or the mechanic, using the fundamental principles of hot-water circulation. We must first know how much hot water is to be used, also the location of the outlets and the construction of the building; then the size of the pipes and the size of the tanks and their locations can be settled. If the job is a large one, a pump may be employed to insure the proper circulation. After this the pipe sizes and connections can be worked out. The one great enemy of hot-water circulation is air.
Therefore, no traps or air pockets should ever appear in the piping system. The boiler, as it is often referred to, is the hot-water storage tank. A copper or iron tank holding sufficient water to supply all fixtures, even when every fixture demands a supply at the same time, is installed in a convenient place and the heating arrangement connected with it. A thermostat can be placed on the system and the temperature of the water controlled. According to the size of the building the problem of furnishing the plumbing fixtures with hot water increases.
METHODS OF HEATING HOT WATER.--There are a number of ways of furnishing hot water. Some of the installations are listed below.
A cast-iron or bra.s.s water back is placed on the fire pot of a stove or furnace. A separate stove with the fire pot and water jacket is used. A coil of steam pipe is placed inside a hot-water boiler or tank. Gas coil heaters are connected with hot water storage tank, also gas coil instantaneous heaters are connected with the piping direct.
Combinations of the above systems are in use and serve the purpose for which they are intended. For instance, the tank can be connected with a coal range and a gas coil heater, heat being furnished by the range alone or the coil heater alone, or both can be used at the same time. This combination can be connected with the furnace in the cellar, and during the winter months, when the furnace is in use, the water can be heated by the furnace coil. In warm weather, when the furnace is out, the range can supply the necessary heat. In hot weather the coil gas heater can supply the heat.
CONNECTIONS OF TANK AND HEATING APPARATUS.--The ordinary house boiler or hot-water storage tank has four connections, two on top, one on the side, and one on the bottom. The top connections are used for the entrance of cold water into the tank and for the supply of hot water to the fixtures (see Fig. 71). The cold-water inlet has a tube extending into the tank below the side connection.
This tube has a small hole filed in it about 6 inches from the top.
This hole is to break any syphonic action that may occur at any time. The side connection is for the connection of the pipe coming from the top of the water back. The bottom opening in the tank is for the connection of the pipe coming from the lower water back connection, also for draining the boiler. The circulation of the water can be followed thus: cold water enters the boiler in the tube and discharges into the boiler below the side connection. From here it flows out of the bottom connection into the water back, through the upper connection into the boiler, through the side opening, then to the top of the boiler and out to the fixtures through the fixture supply opening.
[Ill.u.s.tration: FIG. 71.--Storage tank, and coil heater with thermostatic control valve.]
Fig. 69 shows a thermostatic control valve attached to the bottom of a heater coil, and at the side of storage tank. The best arrangement is at the bottom, for it does not shut off the gas supply until the boiler is full of hot water.
CONNECTING TANK AND COIL GAS HEATER.--The boiler and the coil gas heater have a different connection. The bottom of the tank and the bottom of the heater are connected. The top of the heater and the top of the boiler are connected. The accompanying sketch shows how this connection is made. If the tee on the top of the boiler into which the gas-heater connection is made is not the first fitting and placed as close to the outlet as possible, the water will not circulate freely into the boiler. This connection according to the drawing should be studied and memorized.
[Ill.u.s.tration: FIG. 72.--Instantaneous gas heater. Showing circulation heater or booster.]
INSTANTANEOUS GAS-HEATER CONNECTIONS.--An instantaneous gas heater is placed in the bas.e.m.e.nt. The copper coil in it is connected at the bottom with the cold-water supply and the top outlet of the coil is connected with the hot-water system of piping. There is no need of a storage tank with this heater. When a faucet is opened in any part of the hot-water piping system, the water pa.s.sing through the water valve at the heater causes the gas valve to open so that the whole set of burners in the heater is supplied with gas, and the burners are lighted from a pilot light. When the faucet is closed, the gas supply is shut off and the burners are put out. The pilot is lighted all the time. s.p.a.ce will not permit going over these connections in detail. It is a large field and requires considerable thought.
SAFETY AND CHECK VALVES.--When a meter is used on a water system, the water company demands that a check valve be placed on the hot-water system to prevent the hot water from being forced back into the meter in case the pressure got strong enough in the boiler. If a check valve is used for this purpose, or for any other purpose, a safety valve must be placed on the boiler piping system to relieve any excessive pressure that may be caused by having the check valve in use. There is today, with meters of modern type, no reason to use a check valve or a safety valve. If an excessive pressure is obtained in the boiler, it is relieved in the water main.
When water is heated, it expands. If the heat becomes more intense and steam is formed, the expansion is much greater, and some means must be provided to allow for it. This expansion can be allowed to relieve itself in the water main as explained above. When a check valve is placed on the piping, this means of escape is shut off and a safety valve must be employed. Without these reliefs, the pressure would be so great that an explosion would result. When steel pipe and steel boilers are used for storage tanks and connections, the pipe and tank will shortly start to rust and parts of the piping are stopped up with rust scales. The water also becomes red with rust when the water becomes hot enough to circulate. When the pipes are stopped up, steam is formed and a snapping and cracking sound is heard. To avoid these conditions, the piping should be of bra.s.s or lead and the storage tank should be of copper. The installation cost of bra.s.s and copper is greater than steel, but they will not have to be replaced in two or three years, as is the case with other material. A valve should be placed on the cold-water supply to control the entire hot-water piping system. A pipe with a stop c.o.c.k should be placed underneath the boiler and should extend into a sink in the bas.e.m.e.nt so that the boiler can be drained at any time for cleaning or repairs.
CONNECTING WITH FIXTURES.--To have all fixtures properly supplied with hot water it is necessary to run what is termed a circulating pipe. This circulating pipe is a circuit of pipe extending from the top of the boiler to the vicinity of the fixtures and then returning to the boiler and connecting into the pipe leading out of the bottom of the boiler. From this circuit all branches are taken to supply all fixtures requiring hot water. This circulating pipe has hot water circulating through it all the time. Therefore the fixtures are supplied with hot water very quickly. The circulating pipe and its branches are run without any traps or air pockets.
[Ill.u.s.tration: FIG. 73.--Expansion loop. Four 90 ells.]
[Ill.u.s.tration: FIG. 74.--Expansion loop. Five 90 ells.]
[Ill.u.s.tration: FIG. 75.--Expansion loop. Six 90 ells.]
When running the piping, it should be borne in mind that not only does the water expand when heated, but the pipe expands also.
Therefore due allowance must be made for this expansion. The long risers should have an expansion loop as shown in Figs. 73, 74 and 75. There are installed on some jobs what is known as an expansion joint. This will allow for the expansion and contraction of the pipe. The writer"s experience with these joints has not been very satisfactory. After a while these joints begin to leak and they must have attention which in some cases is rather expensive. An expansion loop as shown in the sketch, made with elbows, will prove satisfactory. If the threads on the fittings and pipe are good, no leak will appear on this joint.
All gas heaters must be connected with a flue to carry off the products of combustion.