Part 16 (2/2)

FITTINGS

The fittings used in screw pipe work are cast-iron recess type (see Fig. 54). The fittings are so made that the inside bores of the pipe and the fittings come in direct line with each other, thus making a smooth inside surface at all bends. The fittings are all heavily galvanized. All fittings should be examined on the inside for any lumps of metal of sufficient size to catch solid waste matter, and these must be removed or the fitting discarded. All 90 bends, whether Ts or elbows, are tapped to give the pipe that connects with them a pitch of at least 1/4 inch to the foot.

Except where obligatory, 90 fittings should not be used. To make a bend of 90 a Y-branch, a nipple and a 45 bend should be used, or two 45 bends will make a long easy sweep of the drainage pipes and reduce the possibility of stoppage.

Y-branches are inserted every 30 feet at least to allow for a clean-out which can be placed in the branch of the fitting. When a clean-out is placed an iron plug should not be used. These plugs are not removed very often and an iron plug will rust in and be almost impossible to get out. Bra.s.s clean-out plugs are used and are easily taken out.

At times it is necessary to connect cast iron and wrought iron, or in a line where a union could be used if the pipe were not a waste pipe, a tucker fitting is used. This fitting is threaded on one end and has a socket on the other to allow for caulking. To get a good idea of all the fittings in general use, the reader should get a catalogue from one of the fitting manufacturers and a survey of it will give the names and sizes of the fittings. However, I show a few common ones. In the writer's opinion, the studying of the catalogue would be of more benefit than a description of fittings at this point. The sizes used and the methods employed to vent the waste-pipe systems are the same as in cast-iron work.

HANGERS AND SUPPORTS

The hanging of screw pipe is a very essential point. The taking of the strain off from a fitting or line of pipe by the use of a hanger is the means of avoiding serious trouble after a job is completed. On horizontal runs hangers are placed not more than 8 feet apart. In a building constructed of wood, the hangers are secured to the joists. In a building constructed of steel beams and concrete the hangers are secured to the steel beams by means of I-beam hangers that clamp on the beams; also in the case of concrete the hangers are extended through the floor and a T is put on the hanger on top of the cement floor; an iron bar or a short piece of smaller pipe run through the T holds the hanger in place and secures it rigidly. The finished floor is laid over the hanger so that it does not show from the top. Hangers on the vertical lines should be placed at every joint and under each fitting. To have the pipe in true alignment, the hangers must be hung and placed in line. Every riser line must have an extra support at the base to avoid any settling of the stack which will crack the fittings and break fixture connections.

MEASUREMENTS

The proper installation of screw pipe work requires getting correct and accurate measurements. Every plumber is or should be able to get correct center to center, center to end, end to end, center to back, and end to back measurements. In Durham work 45 angles are continually occurring. To get these measurements correctly, the following table has been compiled as used by the author and found to be correct. The reader should memorize it so that it may be used without referring to the book.

MEASUREMENTS

------------+------------+------------- Soil pipe | Screw pipe | Multiplier ------------+------------+------------- 1/6 bend | 60 | 1.15 1/8 ” | 45 | 1.41 1/12 ” | 30 | 2.

1/16 ” | 22-1/2 | 2.61 1/32 ” | 11-1/4 | 5.12 1/64 ” | 5-5/8 | 10.22 ------------+------------+-------------

Before any measurements are taken, the lines of pipe are laid out and the position of each fitting known. As I have stated before, the plumber must look ahead with his work. He must have the ability of practically seeing the pipe in place before the work is started.

This requires experience and judgment. Before the measurements are taken and the pipe cut consideration must be given to the fact that the fittings and pipes must be screwed into position. Therefore, ”can the fitting on the pipe be placed where it is laid out when this is considered?” must be one of the many questions a plumber should ask himself. Allowance must be made for the chain tongs to swing. Whenever possible, a fitting is made up on the pipe while the pipe is in the vise.

[Ill.u.s.tration: FIG. 76.--The offset is B or 12 inches center to center. The offset is made using 45 degree fittings. Therefore the length of A from the center of one fitting to the center of the other is B 1.41 = 12 1.41 = 16.92 inches.]

FIXTURE CONNECTIONS

The fixture connections when screw pipe is used are necessarily different than when cast-iron pipe is used. A bra.s.s nipple is wiped on a piece of lead pipe and then screwed into the fitting left for the closet connection. The lead is f.l.a.n.g.ed over above the floor and the closet set on it. The lead is soldered to a bra.s.s f.l.a.n.g.e. The bra.s.s f.l.a.n.g.e is secured to the floor and then the closet bowl secured to the bra.s.s f.l.a.n.g.e. Another method employed is to screw a bra.s.s f.l.a.n.g.e into the fitting so that when it is made up the f.l.a.n.g.e will come level with the floor; the closet bowl is then secured to this f.l.a.n.g.e. There are a number of patented floor f.l.a.n.g.es for closet bowl connections that can be used to advantage. Slop sinks have practically the same connections as the closets. Other fixtures such as the urinal, lavatory, and bath, can be connected with a short piece of lead wiped on a solder nipple, or the tr.i.m.m.i.n.gs for the fixture can be had with bra.s.s having iron pipe size threads, and the connection can then be made directly with the outlet on the waste line. This is a very general way to describe the connections, but s.p.a.ce will not allow a detailed description of these connections. It is always well to allow for short lead connections for fixtures so that the lead will give if the stack settles.

CHAPTER XVII

GAS FITTING, PIPE AND FITTINGS, THREADING, MEASURING, AND TESTING

GAS AND ITS USE IN BUILDINGS

Gas is in common use in all cla.s.ses of buildings today. Dwellings use it for cooking and illuminating, factories, office buildings, and public buildings for power. In some parts of the country natural gas is found. In these places it is used freely for heating fuel. The actual making of gas is something that every plumber should understand. If s.p.a.ce permitted I would describe a gas plant with all of its by-products. However, we shall deal only with the actual installation of gas piping in buildings. Gas mains are run through the streets the same as water mains are run. Branches are taken off these mains and extended into the buildings requiring gas. The gas company generally installs the gas service pipe inside of the bas.e.m.e.nt wall and places a stop c.o.c.k on it free of charge.

This stop that is placed on the pipe is a plug core type, the handle for turning it off is square, and a wrench is required to turn it. The square top has a lug on it. There is also a lug corresponding to it on the body of the valve. When the valve is shut off, these two lugs are together. Each lug has a hole in it large enough for a padlock ring to pa.s.s through. This gives the gas company absolute control of the gas in the building.

SETTING OF THE METER.--Every building that is supplied with gas has a meter that registers the amount of gas consumed. This meter is placed on the service pipe on the house side of the above-mentioned stop c.o.c.k. This meter is furnished free of charge with a trivial charge made for setting up. The actual setting of this meter is not made until the piping throughout the building has had a thorough and satisfactory test and is found free from all leaks. The meter must be set level on a substantial bracket and in a place, if possible, where it will not require an artificial light to read its dial. The dry meter is usually used in dwellings. The interesting construction and mechanism of this meter cannot be discussed here.

<script>