Rejected meters. The manufacturer shall at his own expense replace or satisfactorily readjust all meters rejected for failure to comply with these specifications. Standardization of meter dials. The standard specifications for meters of the disc, current, compound and fire service types were formulated with the coöperation of the meter manufacturers. Standardization of dials has not proven possible to date. The straight reading register could be readily standardized as to form. It seems probable that the use of the two units of measurements of the cubic foot and the gallon will have to continue indefinitely. The joint committee of the New England and American Water Works Associations is continuing the study of the above questions of standardization. INFORMATION TO BE FURNISHED TO METER MANUFACTURERS WHEN REQUESTED TO SUBMIT BIDS ON DISC METERS 1. Meters shall conform to the Standard Specifications for Cold Water Meters, Disc Type, adopted by the American and New England Water Works Associations. 2. The manufacturer shall state in his bid the type of meter he proposes to furnish, as listed in his catalogue. The actual capacity of each size of meter called for is to be given graphically from 0 pounds up to 25 pounds loss of pressure. If this capacity be stated in the manufacturer's catalogue reference may be made thereto. 3. No bid will be considered on meters of a design which has not been listed for at least one year in the catalogue regularly issued by the manufacturer. 4. The method of testing meters shall conform to that recommended by the Committee on Standard Specifications for Water Meters. 5. (a)* The meters are to be accepted on a certificate furnished by the manufacturers that the meters have met the requirements of the Standard Specifications for Water Meters, as adopted by the American and New England Water Works Associations. (b)* The meters will be tested by the purchaser to determine whether they do or do not comply with the Standard Specifications for water meters adopted by the American and New England Water Works Associations. EQUIPMENT NECESSARY TO TEST METERS FOR COMPLIANCE WITH REGISTRATION The standard specifications require that meters shall accurately record the flow within certain limits and shall pass a given quantity of water with a maximum loss of pressure. Suitable equipment to make accurate tests must * Sentence (a) is to be used where the purchaser does not have suitable equipment to test the meters. If he has such equipment then sentence (b) is to be used. be available before the purchaser should make complaint of meters not complying with the specifications. The minimum test equipment required for registration and capacity is as follows: 1. A quick-acting valve on the supply pipe through the use of which the flow can be started and stopped without appreciable loss of time. 2. A valve on the outlet side of the meter which can be used to establish the rate of flow desired. 3. Pressure gages connected on both the inlet and outlet of the meter to show whether any material change in pressure occurs during the period of test which would affect the rate of flow. The outlet pipe is to have sufficient head on it so that the meter will always have pressure on its outlet end and preferably not less than 5 pounds per square inch. 4. A measuring device which may be either of the volumetric or weighing type. Whichever is used, the accuracy of determination of the volume or weight of water discharged into the measuring device must be such as to bring the limit of error within one-tenth of 1 per cent. The volume of water passed must be sufficient to cause at least one revolution of the pointer on the initial dial except for test at "minimum test flow" rate. For the latter test, the amount passed shall not be less than one cubic foot. It is desirable to have available for testing meters a test table and appurtenances which are manufactured by several concerns. Such an outfit would include the equipment enumerated in the preceding four paragraphs. For the capacity tests, it is necessary to add to the above equipment, two piezometer rings which must be of exactly the same diameter. The piezometer rings must be free from any burrs where the holes are drilled through the wall of the ring and not less than four holes shall be provided, drilled in pairs and on diameters at right angles to one another. The inlet piezometer ring shall be set close to the meter and shall be at a distance of not less than eight diameters from the nearest upstream stop-cock or fitting in the supply pipe. The outlet piezometer ring shall be placed at a distance of not less than eight nor more than ten diameters from the outlet of the meter. The diameter of the piezometer rings and inlet and outlet pipes shall be the same as the size of the meter to be tested. The piezometer rings are to be connected by either rubber or metal tubing to a mercury U-tube. To this U-tube is to be attached an accurate adjustable scale for measuring the differences between the inlet and outlet pressures. Provision is to be made for the complete removal of air from the tubing connected with the U-tube, and the U-tube and the tubing connected therewith are to be so placed that the air will rise to the outlets. Where relatively high flows are to be recorded, it is necessary to read both sides of the mercury column to compensate, as far as practicable, for irregularities in the diameter of the glass U-tube and such readings are to be made as nearly simultaneously as possible to avoid errors due to fluctuations. TESTS OF METERS RECOMMENDED The tests to be made on the meter are divided into two classes: 1, Capacity test; 2, Registration test. Capacity tests are those which test the design of the meter rather than the workmanship thereof. When a meter of a given make has once been tested for capacity it should not be necessary to again test this type of meter unless a change has been made in its design. The registration tests should be made on each meter, as the results are affected by workmanship and assembly of individual meters. There is no certainty that, because one meter of a given make comes within certain limits of accuracy, another meter of the same make turned out by the factory on the same day will necessarily give similar results. The register furnished with each meter should be used by both the manufacturer and purchaser in making registration tests. Where the purchaser does not have the necessary equipment to test the meters, there should be furnished by the manufacturer a certificate that each meter has been tested for accuracy of registration and complies with the standard specifications in this respect, and that the type of meter furnished has complied with the capacity requirements. The registration tests recommended are as follows: All meters should be tested for accuracy of registration within and as near as practicable to the low and high rates given under "Normal Test Flow Limits." A test at the "Minimum Test Flow" should be made on as many as possible and not less than 5 per cent of the meters. If the results obtained from testing 5 per cent of the meters show that any meter does not comply with the low flow requirement, additional meters should be tested to the extent deemed necessary to make certain that the other meters do comply therewith. The pressure test should be made on each size of meter furnished of a particular type. This pressure is to be 150 pounds per square inch and the pressure may be furnished through the use of a hand pump or such other method as may be available. Before the meter has been tested by static pressure and also after it has been so tested, it should be tested for accuracy to see whether the meter has been so distorted as to affect registration. It is considered unnecessary to make a pressure test of each size of meter of a given type more than once if satisfactory results are obtained. If it be possible to give a working pressure test under 150 pounds per square inch then such a test should be applied rather than a static pressure test. SPECIFICATIONS FOR CHEMICALS USED IN WATER PURIFICATION SAMPLING AND TESTING 1. Sampling and testing a. The composition of the chemicals shall be determined by analyzing samples taken promptly upon the arrival of the material at the point of consumption. b. When chemicals are shipped in bulk, the sample shall be so taken that it will represent an average of all parts of the shipment from top to bottom, and shall not contain a disproportionate share of the top and bottom layers. It shall weigh at least 10 pounds (in the case of lump lime 100 pounds) and shall be crushed if necessary and mixed thoroughly, and "quartered" to provide two 1-pound samples, one of which shall be used for the immediate testing and the other of which shall be kept carefully sealed for use in a possible retest as provided hereinafter. c. When shipped in packages at least 3 per cent of the number of packages shall be sampled. They shall be taken from various parts of the shipment, dumped, mixed and sampled as in the above paragraph. d. When sampling quicklime or hydrated lime, it is essential that the operation be conducted as expeditiously as possible, in order to avoid undue exposure of the material to the air. The sample to be sent to the laboratory shall immediately be placed in an air-tight container in which the unused portion shall be stored until the shipment has been finally accepted or rejected by the purchaser. 2. Retesting a. Notice of dissatisfaction with a shipment based on these specifications must be in the hands of the consignor within ten days after the receipt of the shipment at the point of destination. If the consignor desires a retest, he shall notify the consignee within five days of receipt of the notice of complaint. The duplicate sample shall then be forwarded for a retest to some laboratory agreed upon by both parties. This retest shall be made at the expense of the consignor. The results of the retest shall be accepted as final. SULPHATE OF ALUMINA 1. Chemical requirements a. The material shall be basic, shall contain not less than 17 per cent available water-soluble alumina (Al2O3) and shall not contain more than 0.75 per cent iron (Fe2O3). 2. Insoluble matter a. Sulphate of alumina from which the insoluble material has been removed shall contain not more than 0.5 per cent of material insoluble in distilled water. b. Sulphate of alumina from which the insoluble material has not been removed shall contain not more than 7.5 per cent of material insoluble in distilled water. 3. Size of lumps or grains a. Lump sulphate of alumina shall range in size from to 3 inches. b. Ground sulphate of alumina for use in dry feeding machines shall be of such size that not less than 95 per cent shall pass a woven sieve having 10 meshes per linear inch, and 100 per cent shall pass a sieve having 4 meshes per linear inch. 4. Packing and shipment a. Sulphate of alumina may be shipped in bulk, in bags of uniform weight or in barrels of uniform weight. SODA ASH 1. Chemical requirements The soda ash shall be that known as 58 per cent light soda ash and shall contain not less than 98 per cent of sodium carbonate. The material shall be in a dry powdered form, shall contain no large lumps or large crystals, and shall be free from chips and other foreign matter. 2. Packing and shipment Soda ash may be shipped in bulk, in bags containing a uniform weight or in barrels containing a uniform weight. CAUSTIC SODA 1. Chemical requirements The caustic soda shall be that known as 76 per cent actual test sodium oxide and shall contain not less than 98 per cent sodium hydroxide (NaOH). The dry material is manufactured in 3 forms, viz., solid, ground and flaked. 2. Packing and shipment Solid caustic soda is customarily shipped in steel drums containing approximately 700 pounds net weight. The ground and flake material is commonly shipped in steel drums or in wooden barrels containing approximately 400 pounds. LIME 1. Slaking When lumps of quicklime are immersed in water, they shall readily disintegrate into a suspension of finely divided material. |