Document KGXxaxjkjZZ2YvNn1LJqBpVBo

American Society, of Heating and Ventilating Engineers Guide, 1924-25 LOG,SHEET NO. 4 Date................................................................ Detailed Record of Gas Analysis Test No. Time' COa COa + Oa Oa COa + Oa + CO CO N Remarks Date No. LOG SHEET NO. 5 Smoke Readings Test No. Time RlNGELMANN Chart No. Time RlNGELMANN Chart Remarks -> Chapter VII PUMPS FOR HEATING AND VENTILATING EQUIPMENT \ INTRODUCTION THE use of pumps in connection with the heating and ventilating of buildings, has increased rapidly during the past few years. There are three or more reasons for this as follows: 1. The great increase in the number of large buildings. 2. The increasing use of electricity for industrial purposes together with the development of reliable motor driven pumps, and 3. The desire to eliminate high pressure boiler plants where steam is used only for heating purposes. In applying pumps to heating systems, particularly vacuum pumps, there are a few fundamental principles which the engineer must consider in determining the proper pump for a given installation. These factors include the proper trapping of returns; the probable load factor; the lifts in the system, if any; the required discharge pressure in delivering the condensate; and, above all, a determination of the heating surface to be handled reduced to the value of equivalent direct radiation. It is as an aid to the proper determination of pump ratings and capaci ties, therefore, that the following information is given. The various kinds of pumps ordinarily used in connection with heating and ventilating installations may be classed under the following heads. 1. Boiler feed pumps. 2. Condensation return pumps. 3. Return line vacuum heating pumps. 4. Sump pumps. 5. Forced circulation hot-water heating pumps. 6. Circulating pumps for water brine, etc. ' 7. Refrigeration pumps and compressors. Boiler feed pumps may be of the following types: i 1. Direct acting steam driven reciprocating pumps. r 2. Power driven reciprocating pumps. 3. Centrifugal pumps. 4. Screw pumps. The capacity of a boiler feed pump should be based on 34.5 lb. of water per hr. per maximum boiler horse-power served, with a slippage allow ance of 10 per cent in the water cylinders and a factor of safety allowance of 2 for intermittently operating pumps and a factor of safety allowance of l}/2 for continuous operating pumps, to provide for unusual demands when the water in boilers becomes low or excessive loads are carried. Material for this section especially prepared for The Guide by Perry West. Newark. N. J., and R. H. Carpenter, New York. 75