You may tap the boiler at any point, but the waterback must remain the same.

(23) Mention some of the most important matters to be considered in the inspection of the following materials: (a) cast-iron soil pipes and fittings; (b) earthen drain pipes and fittings.

(24) State the proper sizes of waste pipes for the different plumbing fixtures in general use.

fig. i.

Fig. i.

(25) Describe the pneumatic system of water supply and distribution. What are its principal advantages and disadvantages?

(26) (a) How should vertical wrought-iron stacks and vertical cast-iron stacks be supported? Give reasons, (b) Describe a heel-rest bend. Explain its use and state where it should be located.

(27) What should be considered in piping a building for coal gas, (a) regarding condensation in the pipes? (b) regarding the fittings used? (c) regarding the supports for drop nipples for hanging fixtures?

(28) Clearly explain the use of the pilot light for lighting inaccessible clusters of burners.

(29) What is about the proper height for side lights and hanging fixtures in an ordinary dwelling?

(30) Describe the ordinary, the French, and the Roman bath tub, and give a sketch of each.

(31) Describe, with sketch, how a porcelain water closet should be connected to a 4-inch lead bend which runs under the floor.

(32) Suppose that a wash basin on the second floor is located a considerable distance from the boiler on the first floor, and that the cold water lying in the pipe must be drawn off before hot water can be obtained at the basin; how can the piping be so arranged that hot water will flow from the faucet at the instant it is opened?

(33) (a) What is a trap as understood in plumbing? (b) Show by sketch the seal of a 2-inch round-pipe S trap.

(34) What points should be considered regarding offsets and branches on soil-pipe and house-drainage work? Give reasons.

(35) A stream of pure water having a fall of 7 feet in 40 feet, flows within 600 feet of a building. What is the best method of supplying the building with water from the stream? Explain how the apparatus should be fitted up and describe its action.

(36) Upon applying the hydrostatic test to a system of cast-iron drains and soil pipes, the following defects were observed: (a) a joint leaking slightly around the calking; (b) a leak due to a split socket; (c) a leak from a split in the pipe; (d) a flaw in the casting. How should these defects be remedied?

(37) If the meter a, Fig. 80, Plumbing and Gas-Fitting, were placed in the basement directly under the dining-room double window, and the gas fixtures all remain in the positions shown in Figs. 80 and 81, show by drawings how you would run the gas piping for the building, and mark the nominal sizes of the pipes upon your drawings. Allow for a 1-jet pillar light to be set on the newel post at the foot of the stairs.

(38) What are safety burners? Explain their use, and in a general way describe their operation.

(39) (a) The chemical symbol of a certain gas is C2H1. What is the commercial name of this gas? (b) How, and from what substances, is it made? (c) Can this gas be burned properly by ordinary lava-tip burners? Give reasons.

(40) Describe a combination bath cock and explain its use.

(41) Describe the construction and operation of the ordinary siphon tank so commonly used to flush water closets.

(42) Suppose that a building is to be supplied with water from two separate sources; for instance, a tank placed on the top of the building which will furnish hot and cold water to the upper floors, and the street mains which will furnish hot and cold water to the lower floors. One waterback must heat the water for the entire building, (a) What class of a boiler would you use, and why, and of what material should the boiler be made? (b) Give a sketch of the boiler and the pipe connections. Show by arrows the currents of circulation.

(43) Distinguish between a Du Bois trap and a bottle trap. Which is the better form for ordinary service? Give your reasons.

(44) Where should back-vent pipes connect to round-pipe traps? Give your reasons, and state the disadvantage of connecting precisely on the crown.

(45) The last time the meter dial shown in Fig. 2 was read, it indicated 6,417 cubic feet; how many cubic feet of water have passed through the meter since that time?

(46) What class of a hot-air engine would you use to raise water from a well 75 feet deep to a house tank 100 feet above it? Suppose the man in charge of the pump to be a gardener. Give your reasons.

(47) What considerations should govern the architect in selecting the location of gas pipes?

(48) What are the principal points to be considered in the selection of globes and shades for gas burners? Give reasons.

(49) Clearly describe the Rumford photometer. What is the objection to this contrivance?

(50) Describe, with sketches, two common forms of standing wastes for baths, and mention their advantages or disadvantages.

(51) What class of flushing apparatus may be used to automatically flush a urinal every five minutes? Explain how it operates.

(52) Briefly describe the construction of (a) round wooden tanks; (b) rectangular wooden tanks, (c) Where are they generally used? Give your reasons.

Plumbing And Gas Fitting Arts 1 261 Sec 16 Part 2 326

Fig. 2.

(53) What are the requirements of a good trap? State them fully and clearly.

(54) What is the proper height for back-vent branches to connect to a vent stack. Give your reasons.

(55) Draw to a scale of double the size the fixtures shown in Fig. 62, Art. 169, Plumbing atid Gas-Fitting. Let the 1-inch water-supply pipe enter from the right instead of the left, as shown in the figure, and take off branches to the different fixtures. Mark diameters of pipes.