W. P. B. ASKS BIDS FOR 2,258,000 STIRRUP PUMPS
Design Eliminates Use of Critical Materials, Rubber Hose Tabooed
THE War Production Board is asking bids for the manufacture of 2,258,000 stirrup pumps for civilian defense. Contracts are to be let this month.
Specifications are of interest because of the elimination of critical materials. Below a,re reproduced some of the more important features of the pumps as set forth in the specifications.
This pump is designed to be used for fire extinguishment in conjunction with a common water pail or any other type of suitable container. It shall consist of (1) a pump to discharge the liquid; (2) a hose to convey the liquid to the point of discharge; (3) a dual purpose nozzle to apply the liquid to the fire; (4) a suitable stirrup stand to hold the pump .rigid and upright in a water container during pumping operations.
This pump shall be sturdily constructed to withstand the shocks and strains to which it will be subjected but of minimum weight; shall be sufficiently corrosion-resistant to permit lengthy storage and intermittant use without deterioration; shall be arranged and constructed so as to permit ease in operation and shall be of definite standard dimensions with proper clearances and fits.
The pump shall be of the manually operated, single suction, double discharge type. Pump shall be so built that when being operated, pressure and capacity characteristics will be sufficient to develop a stream with horizontal range of at least thirty feet (30′) through the hose and nozzle required.
Pump discharge head shall be of ferrous metal casting or stamping of best quality, of satisfactory thickness for the service required and properly coated to prevent corrosion. Discharge port shall be of such outside diameter and properly notched so that standard threeeighths inch (3/8″) hose, fastened with a conventional type ferrous metal water hose clamp, will be well secured.
Inside diameter of the discharge port shall be sufficient for operation characteristics required but not less than onequarter inch (1/4″).
Pump cylinder shall be of seamless or welded steel tubing having an outside diameter of one and one-eighth inches (1 1/8″) and wall thickness of forty-thousandths of an inch (0.040″), if tube is threaded, or of thirty-five thousandths of an inch (0.035″) if tube is not threaded. Tubing shall be adequately protected by porcelain enamel inside and out with the inside surface sufficiently smooth, uniform, and free from imperfections to assure the required pumping characteristics without undue wear or friction.
Suction valve assembly shall be const.ructed of plastics or other non-mctallic material having like characteristics which will efficiently replace brass, and shall be tightly secured in the bottom of the pump cylinder. Assembly shall be designed to permit the passage of an adequate amount of liquid so that the pumping characteristics required may be produced and proper operation of valve under all conditions may be assured. A glass ball type valve of the best quality and of the proper size and design to permit satisfactory operation, shall be used; and seat shall be of nonmetallic material having such characteristics that it will efficiently replace brass, to assure proper seating with a minimum of leakage.
Strainer shall be of plastic or other non-metallic material having like characteristics which will efficiently replace brass, securely fastened to the bottom of the intake valve assembly. Maximum openings in the strainer shall not be greater than three thirty seconds of an inch (3/32″) in diameter but the total open area presented shall be at least twenty times the area of the discharge nozzle.
Plunger tube shall be of seamless or welded steel tubing having a wall thickness of forty-thousandths of an inch (0.040″), if tube is threaded, or of thirtyfive thousandths of an inch (0.035″) if not threaded, and of a diameter which will permit the discharge of approximately the same amount of liquid on the upstroke as on the downstroke. Tubing shall be adequately protected by porcelain enamel inside and out with the outside surface sufficiently smooth, uniform, and free from imperfections to secure proper pump operation without undue wear or friction.
Discharge valve assembly shall be of plastic or other non-metallic material having like characteristics which will efficiently replace brass. A glass ball-type valve of best quality and of proper size and design to permit satisfactory operation shall be used, and seat shall be o. plastic or other non-metallic material having like characteristics which will efficiently replace brass, to assure proper seating with a minimum of leakage.
Plunger shall be of plastic. Buna type synthetic rubber or an acceptable equal, securely attached to the plunger tube and with ample clearance from the cylinder walls to minimize friction and wear.
Ten feet (10′) of hose other than rubber, reclaimed rubber, or synthetic rubber three-eighths of an inch (3/8″) internal diameter, shall be provided with each unit, for attachment to the discharge opening of the pump cylinder by means of an effective, universal, adjustable, ferrous metal type hose clamp. Hose shall be reasonably kink-proof. Hose shall be capable of withstanding a hydrostatic pressure of one hundred pounds (100 lbs.) per square inch, and shall be demonstrated to, and meet the approval of the Fire Equipment Section. Safety and Technical Equipment Branch, Division of Industry Operations, War Production Board, before it is incorporated into completed units and delivered.
A one-eighth inch (1/8″) diameter smooth bore dual purpose plastic nozzle or a nozzle made of material other than copper, chromium or nickel alloy, having equal corrosion resistance and strength characteristics, shall be provided, secured to the hose by means of an effective, universal, adjustable, ferrous metal hose clamp. The nozzle must not be cemented to the hose. The nozzle shall be of such construction as to emit the water in spray fo.rm except when manually held for a solid stream operation. The construction of the nozzle will also be made in such a manner as to permit it to be cleaned and serviced without disturbing connection to the hose.