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manding and permitting the several bidders to estimate on different amounts of heating-surface for exactly the same work. The minimum amount should be determined by some one individual, who should be recompensed for this service, and he alone held responsible for this estimate. The owner or architect should indicate on the building plans where surfaces shall be placed, bearing in mind always the room required in the allotted spaces and also the requirements of the system. This is necessary for the contractor to know, since on it depend the number of his riser-lines and the amount of piping in his boiler-room.

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"When feasible, the owner or architect should indicate all the specialties' desired in the apparatus, and each bidder should be compelled to figure as nearly as possible on exactly the same set of specifications. This method is just to those who estimate in good faith, and usually closer and lower figures will be obtained by the owner. The contractor, with these data before him, takes dimensions either from the architect's plans or from the measurements of the building itself; he then computes the quantity and cost of all materials which will be used in the completed apparatus; the method of computation varying from that of pure guesswork or shrewd estimating' to that of painstaking measurement and actual figuring out of the exact amount of stock required, together with its purchasable cost from the trade catalogues and price-lists.

"To the net cost for material, including boiler, radiators, pipe, fittings, valves, vents, floor- and ceiling-plates, registers, ducts, covering, painting, bronzing, smoke-pipe, freight and cartage, board, car-fares, labor, and incidentals, is added such a margin of profit as the contractor considers his experience, reputation, and workmanship are entitled to.

"In justice to the bidders the conditions of the award should be clearly set forth beforehand, and it should be stated. whether this work will go to the lowest bidder, or whether a 'preference' (often justified) is to be given a certain contractor. When it is known that the preparation of a set of specifications and of an estimate of cost is an expense, and often not a small one, to each and every bidder, the injustice of requiring all to bear this instead of having it done.

once and for all is too evident for argument. It is for this reason that a uniform standard specification is recommended by the National Association of Manufacturers of Heating Apparatus.

"Suppose now the award be made to the lowest bidder, bids having been made on the same set of specifications which embody full statements in regard to requirements of the completed plant. The owner (or architect) and the contractor are then to execute a proper contract for the performance of the work and for the payments therefor. Then each should be required to fulfil the conditions of said contract. The National Association of Master Steam and Hot-water Fitters has adopted a uniform standard contract which seems to meet the requirements and is quite generally accepted in such cases. The form is given below and may be obtained of the secretary of that association.

172. Form Proposed by the National Association of Manufacturers of Heating Apparatus.-For a steam-heating plant.

UNIFORM STANDARD SPECIFICATION FOR A COMPLETE LOW-PRESSURE STEAM OR HOT-WATER HEATING APPARATUS.

NOTE. -All clauses and terms in this type and enclosed in brackets [ ] apply only to hot water. All clauses and terms in this type and enclosed in parenthesis () apply only to steam. Words in italics are to be supplied in

each contract.

TO BE INSTALLED AND ERECTED COMPLETE IN

the three-story stone and frame residence

OWNED BY

I. N. Vestor, No. 75 Broadway, New York City,

LOCATED AT

N. W. Corner of State and Hudson Streets, Yonkers, N. Y.

THE HEATING SYSTEM

shall be erected according to the single pipe method of (steam) [water] heating, the (steam) [water] to circulate (under a pressure) [at a temperature] never exceeding (three (3) pounds to the square inch at) [— degrees F. in the flow-pipes of] the boiler,

conveyed to heating surfaces by a system of piping so erected that all water (of condensation) in the system shall be freely eturned to boiler by gravity alone.

(STEAM GENERATOR.) [WATER HEATER.]

The (steam) [water] shall be (generated) [heated] by one No. 2 Vertical Tubular Sectional Boiler, manufactured by C. Iron & Co., N. Y. City, and by them guaranteed free from all flaws and defects. Said boiler to have a grate area of 700 square inches, capable of burning all kinds of coal as fuel, and guaranteed by makers to be capable of supplying (steam) [water] to 750 net square feet of direct radiation without "forcing"; boilers to be certified by manufacturer to be able to stand a cold-water pressure of 80 pounds to the square inch.

An opening not less than two (2) feet by five (5) feet into the building and boiler-room shall be provided by owner.

BOILER SETTING.

Boiler to be placed as near smoke-flue as possible, upon a level concrete or other equally solid foundation provided by owner. The top to be not less than six-feet from ceiling of boiler-room. All necessary excavating to be done at expense of contractor.

When boiler is set in brickwork same shall be not less than eight (8) inches thick, erected concentric or parallel with external boiler walls as shown by plans of manufacturer. Brick to be hard burned, and laid in courses which break joints, with cement mortar not more than one-fourth inch in thickness. Bond courses of headers to be laid once in every five courses. Setting when complete to be air-tight, and guaranteed to stand all strains of expansion and contraction; or, when plastic covering is used for setting, same shall be evenly distributed over external boiler surfaces not less than two (2) inches thick. The ash-pit shall not be less than twelve inches deep, and shall be sloped to edge of clean-out door. Boiler shall be provided with fire, clean-out, and ash-pit doors, of such form, size, structure, and set in such position as shall make accessible all portions of boiler requiring attention. When setting of boiler demands it, same shall be provided with cast-iron front de

signed by manufacturers for boiler specified. Same to be protected, when necessary, from direct heat of flame by brickwork or other means equally good.

FIXTURES, FIRE TOOLS, AND TRIMMINGS.

Boiler shall be provided with rocking and dumping grates designed by manufacturers for boiler specified, together with shaking-lever and all fire tools necessary to care for same, which shall consist of one (1) poker, one (1) slice-bar, one (1) fine brush and handle. Boiler shall be provided with (one 5" brass-bound low-pressure Bourdon steam-gauge, with stop-cock and siphon), (one (1) low-pressure safety-valve with ten (10) pound weight), (one (1) water-column fitted with two (2) brass trycocks) [expansion thermometer registering from 80 degrees F. to 250 degrees F.] (one Scotch gauge-glass and four (4) brass guardrods), and one automatic [ ] damper regulator with connections for operating draft-door and cold-air check; one 11⁄2 inch brass steam (blow-off) cock with key; and there shall be provided in addition to above all pipe, fittings, and valves necessary to render connection of all of above to boiler complete.

WATER CONNECTIONS AND BLOW-OFF.

Feed-water with its supply-pipe shall be brought within six feet of boiler by owner, and left with one 1/4-inch cast-iron fitting for boiler connection to be made by contractor. (Water supply to be controlled by no automatic water-feed.) Blow-off cock to be located at lowest point of system, with piping so pitching toward same as to allow of draining boiler and of system, same to be fitted for a hose-nipple connection. The discharge to waste opening (provided by owner) shall be always visible.

SMOKE-PIPE AND SMOKE-FLUE.

Contractor shall connect boiler to smoke-flue opening (provided by owner) by means of gas-tight pipe twelve inches in diameter, built of No. 14 galvanized iron, in which shall be placed one (1) shut-off damper with wheel handle attached, together with proper clean-out door. Smoke-flue throughout to be not less than 113 square inches internal area, and 45 feet in

height, straight, and presenting no unusual obstructions to gases. Responsibility for proper working to rest on owner.

FLOW, BRANCH, AND RETURN MAINS.

Flow-pipes and branches shall be run on a grade to or from boiler of not less than one inch fall in each ten feet run; size of pipes to be of such area as to quickly, adequately, and noiselessly carry (steam) [water] by means of branches and risers to heating surfaces, and also to permit an unimpeded flow of all (water of condensation) [return water] to or from boiler by means of mains, branches, or reliefs. The size of pipes shall be gauged by, and shall in no case be reduced below, standards laid down in Carpenter's "Heating and Ventilating Buildings." All mains are to be so run in straight lines, and junctions so made, as to avoid all traps or pockets which may hold air or (water of condensation). (When pitch of pipes brings level of flow-mains within eighteen inches of waterline of boiler, establish higher level for steam-flow, make connection with proper relief, so as to drip all condensation.) All expansion and contraction of pipes throughout system must be provided for in joints thereof so as to prevent buckling or bending of same, and all joints made steam and water tight. [Note. No bushings shall be used on hot-water flow-pipes, whether mains, risers, or radiator connections.]

This system of piping contemplates three (3) flow-mains, 1/2, 2, and 2/2 inches diameter, respectively, pitching from the boilers. There shall also be two (2) return-mains pitching toward the boiler on a grade not less than one inch in (twenty) [fifteen] feet run; same to be carried to boiler on the overhead plan, and to be so connected that there shall be two (2) return-mains entering boiler of not less than one and one quarter' inches in diameter. (Said main to be provided with inch swinging check-valve outside the boiler.)

RISERS (RELIEFS) AND CONNECTIONS.

All risers shall be erected plumb and straight, and all connections thereto shall be made below or in the floors by means of double joints to allow for expansion. When "offsetting"

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