File:Report of committee on sanitation of the School committee (1800) (14759595536).jpg

Identifier: reportofcommitte00lynn (find matches)
Title: Report of committee on sanitation of the School committee
Year: 1800 (1800s)
Authors: Lynn, Mass. School committee. (from old catalog)
Subjects: Public schools School hygiene
Publisher: Lynn, Mass.
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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Text Appearing Before Image:
valve which should 8 -; rft o o o o o o o o o o!1 o o ) llj o i o o o o)o Urina) • : . — ^ 1 •■ , ■ i ■,ll J. PLAN OF FLUSH VAULT FIG. IX. give an unobstructed flow to the water, hold the tankfull at other times, and also be constructed at littlecost. The bell-mouth end of the outlet pipe reaches nearly tothe bottom of the tank, and a flat ring of cast-iron half aninch thick, two-and-a-half inches face and twelve inches indiameter with an inside rim four inches deep, projects intothe enlarged end of the pipe. 20 ANNUAL REPOKT OF THE This ring is screwed to the bottom of the tank, and thejoint made tight by a rubber gasket. The flap-valve con-sists of a cast-iron plate with a boss at one side forming ahinge with a piece secured to the bottom of the tank. The valve face is made of a piece of rubber three six-teenths of an inch thick and is held in place by a circularpiece of board held firm by screws passing through theplate into the wood, which is eleven inches in diameter
Text Appearing After Image:
CROSS-SECTION OF FLUSH VAULT. FIG. X. and projects into the mouth of the outlet pipe when thevalve is shut. The hinge is not rigid, as the bolt is one-half inch indiameter and the hole in the boss from the coveris three-quarters of an inch in diameter, this makes ayielding connection which allows the valve to conform to SCHOOL COMMITTEE. 21 the valve seat described above, and to be held securely toits seat by the water pressure, which under a depth offour feet in the tank amounts to 198 pounds; towhich should be added the weight of the valve, 30 pounds,making the whole load on one of these valves 228 pounds,which is sufficient to keep it perfectly tight. A chainfrom each of these valves extends to a drum on the shaftat the top of the tank, and affords a means of easily open-ing the valves by turning a crank at the end of the shaft.The chain in Fig. XI can be attached to the outer edge ofthe valve, whenever such a connection to the winch maybe more convenient.

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