Document MGOknY80VKj0Yk39QQoxM942L

HEATINC VENTILATING AIR CONDITIONING GUIDE 1941 to 250 lb saturated steam working pressure, although most manufacturers also make valves for medium pressure up to 175 lb steam working pres sure. The more common types are gate valves or straightway valves, globe valves, angle valves, check valves and automatic valves, such as reducing and back-pressure valves. Gate valves are the most frequently used of all valves since in their open position the resistance to flow is a minimum. These valves may be Table 12. American Standard Dimensions of Steel Welding Neck Flanges for Steam Service Pressure Rating of 300 Lb per Sq In. (Gage) at a Temperature of 750 F CHAPTER IT PIPE, FITTINGS, WELDING secured with either a rising or a non-rising stem, although in the smaller sizes the rising stem is more commonly used. The rising stem valve is desirable because the positions of the handle and stem indicate whether the valve is open or closed, although space limitations may prevent its use. The globe valve is less expensive to manufacture than the gate valve, but its peculiar construction offers a high resistance to flow and may prevent complete drainage of the pipe line. These objections are of particular importance in heating work. Check valves are automatic in operation and permit flow in only one direction, depending for operation on the. difference in pressure between Table 13. Standard Roughing-in Dimensions Angle Type Valves Nominal Pots 8ns Diam. or Flange Thick ness or Flo.* Mm. Diam. or Hob Hob Duu. Beginning or Chammb-o-d Length Thbu Hob* Inside Diam. or Pipb Schedule 40o-d X *4 1 14 IX 2 2X 3 3X 4 5 6 8 10 12 14 OD 16 OD 18 OD 20 OD 24 OD 0 3*4 4*4 4% 54 e6mXx 84 9 10 11 12X 15 17X 20% 23 ' 25 Mi 28 30 m; 36 QX 94e *4 imx We 2% *4 2X We 2*4 Vs 3*Ae 1 3% IMS 4*4 We 54 w 5*4 1*4 7 We 8X 1*4 104 1% 12 *4 2 144 24 16*4 2% 19 2% 21 2% 23X 2*4 27*4 H 0.84 1.05 1.32 1.66 1.90 2.38 2.88 3.50 4.00 4.50 5.56 6.63 8.63 10.75 12.75 14.00 16.00 18.00 20.00 24.00 Y 24e 24 2`4e 2*Ae 2We 2*4 3 3% 34 e 3*4 3`4 34 4*4 4*4 5X 5*4 5*4 84 8*4 8*4 J 0.62* 0.82* 1.05* 1.38* 1.61* 2.07* 2.47* 3.07* 3.55* 4.03* 5.05* 6.07* 7.98* 10.02* To Be Spedfied by Purchaser Inside Diam. or Pipe Schedule 80o-d J 0.551 0.74f 0.961 1.28f 1.50f 1.94f 2.32| 2.90| 3.361 3.83 f4.81 f 5.76 f 7.631 To Be Spedfied by Purchaser Diam. or Bolt Circle No. Size or or Bolts Bolts 2*4 4 Mi 34 4 *4 3% 4 *4 34 4 *4 4% 4 *4 5 8 *4 54 8 *4 6*4 8 *4 74 8 *4 74 8 *4 94 8 *4 10*4 12 *4 13 154 12 16 l4 174 16 14 204 20 14 22 Mi 20 14 `24*4 24 W 27 24 14 32 24 IX All dimensions given in inches. A raised face of Ht in. is included in thickness offlange minimum and in length through hub. bThis outside surface of the welding end of the hub shall be straight or tapered at not more than 6 deg eDimensions H and J correspond to the outside and inside diameters of pipe as given in ASA B36.101939, Schedules 40 and 80. Purchaser's order must specify which of these two inside diameters is desired. dThese flanges are regularly bored to match inside diameter of Schedule 40 pipe, but are bored to Schedule 80 pipe when so ordered. These diameters are identical with the diameters of what was formerly designated as Standard Weight Pipe of the corresponding sizes. tThese diameters are identical with the diameters of what was formerly designated as Extra-Strong Pipe of the corresponding sizes. 340 Size or Valve X *4 l 14 IX 2 Tolerance ADimension Steam and Hot Wateb Angle Valves and Union Elbows Effective Januabt 1,1926 Dimension a Modolatino Valves Effective Januabt 1, 1926 24 2*4 2*4 2*4 33 3X 3X 3*4 3*4 4x4 44 y ADimension Return Line Vacuum Valves Effective Januabt 1,1925 34 __ __ _____ ....... . -- All dimensions given in inches. Connecting ends shall be threaded and gaged as to threading according to the American (Taper) Pipe Thread Standard. A-S.A. No. B2--1919. The standardization of the Roughing-in Dimensions of Angle Steam and Hot Water, and Modulating Radiator Valves was made possible by the cooperation of the Manufacturers Standardisation Society of the Valves and Fittings Industry. the two sides of the valve. The two principal kinds of check'valves are the swing check in which a flapper is hinged to swing back and forth, and the lift check in which a dead weight disc moves vertically from its seat. Valves commonly used for controlling steam or water supply to radi ators constitute a special class since they are manufactured to meet heating system requirements. These valves are generally of the angle type and are usually made of brass. Graduations on the heads or lever' handles are often supplied to indicate the relative opening of the valve in any position. Standard roughing-in dimensions Jor angle-type valves are given in Table 13...._ Automatic control of steam supply to individual radiators can be 341