Steam:
Its Generation and Use

mix with the heated water before coming in con- tact with any portion of the boiler. 12. Foaming.—When foaming occurs in a boiler, checking the outflow of steam will usually stop it. If caused by dirty water, blowing down and pumping up will generally cure it. In cases of violent foaming, check the draft and fires. Babcock & Wilcox boilers never foam with good water, unless the water is carried too high. If found to prime, lower the water-line. It should not be carried above centre line of drum. 13. Air Leaks—Be sure that all openings for admission of air to boiler or flues, except through the fire, are carefully stopped. 1 his is frequent- ly an unsuspected cause of serious waste. ' 14. Blowing Off.—If feed-water is muddy or salt, blow off a portion frequently, according to condition of water. Empty the boiler every week or two, and fill up afresh. When surface blow- cocks are used, they should be often opened for a few minutes at a time. Make sure no water is escaping from the blow-off cock when it is sup- posed to be closed. Blow-off cocks and check- valves should be examined every time the boiler is cleaned. Attention Necessary to Secure Durability. 15. Leaks.—When leaks are discovered, they should be repaired as soon as possible. 16. Blowing Off.—Never empty the boiler 17. Filling Up.— Never pump cold water into a hot boiler. Many times leaks, and in shell boilers, serious weaknesses, and sometimes ex- plosions are the result of such an action. 18. Dampness.—Take care that no water comes in contact with the exterior of the boiler from any cause, as it tends to corrode and weaken the boiler. Beware of all dampness in seatings or coverings. 19. Galvanic Action.—Examine frequently parts in contact with copper or brass, where water is present, for signs of corrosion. If water is salt or acid, some metallic zinc placed in the boiler will usually prevent corrosion, but it will need attention and renewal from time to time. 20. Rapid Firing.— In boilers with thick plates or seams exposed to the fire, steam should be raised slowly, and rapid or intense firing avoided. With thin water tubes, however, and adequate water circulation, no damage can come from that cause. 21. Standing Unused.— If a boiler is not re- quired for some time, empty and dry it thor- oughly. If this is impracticable, fill it quite full of water, and put in a quantity of common washing soda. External parts exposed to dampness should receive a coating of linseed oil. 22. General Cleanliness—All things about the boiler room should be kept clean and in good order. Negligence tends to waste and while the brick-work is hot. decay. Babcock & Wilcox Boilers in Chicago City Railway. 1,000 H. P. 79