Document mq0E7arKmx58ngzmGojBm7Q10

Armstrong Machine Wor\s Specialties, Healing neers quite generally should recognize the dependability of Armstrong traps over long periods of time. Easy' Installation--Except in unusual cases, it is practical to install any standard Armstrong Trap with no support* other than the pipe line in which the trap is used. Service Organization--Armstrong Traps are sold and serviced by 43 district representatives in the United States and Canada. Stocks of Armstrong Traps are carried in nearly one hundred leading cities and representatives are responsible for the satisfactory operation of all Arm strong Traps installed in their respective territories. DETERMINING THE SIZE OF ARMSTRONG TRAP REQUIRED For unit heaters (when maximum condensate is known)--In most cases, the informa tion regarding the amount of steam This No. 100 Trap is connected like any valve condensed by a unit heater is furnished by the manufacturer and it is a simple matter to select the trap by referring to the capacity table. Since the capacity table shows continuous discharge figures at the full pressure differential indicated, it follows that allowances must be made for intermittent trap Operation as well as for drop in pressure through the hegter and through the trap. If adequate sized steam lines are used, the drop in pressure through the unit heater should not exceed 25 per cent of the initial pressure but at times the pressure in the heater itself and at the trap will be practically equal to the initial pres sure. For this-reason, any trap selected must have a discharge orifice for operation at the maximum pressure but sufficient/' capacity at the minimum differential pres sure so that it will not be discharging more than one-half of the time. In other words, the continuous discharge capacity of the trap at 75 per cent of the maximum pres-' sure should be at least twice the maximum amount of condensate that is expected from the heater. Another way of stating the same rule is that at the full pressure General Service Cast-Iron Traps PRESSURES TO 300 LBS. Trap Size No. 100 No. 30 No. 31 No. 2 No. 25 No. 3 No. 4 Pipe connections............................... Vz" List prices.......................................... $7.00 Telegraph Code....................... Heignt of trap................................... wAlder Diameter..................................... Weight............................................. 3Vi' 3'/j u. Maximum pressure........................... 125 lbs. '/i $9.25 Oak 4%' 5V 5'/, lbs. 125 lbs. Red w 5%' 71/2 lbs. 150 lbs. Vi' orW $20.75 Ash 10* w 18 lbs. 300 lbs. 1' $29.00 Hickory 12V2' ?/z" 33 lbs. 300 lbs. l* or ws $38.00 Fir 14' 8>/2'. 45 lbs. 300 lbs. IV2' or 2' $55.00 Elm iW 10* 74 lbs. 300 lbs. Capacity in pounds of water per hour at these pressures 5 10 15 20 25 30 40 50 60 70. 60 90 100 125 150 160 240 300 450 550 600 . 660 370 385 420; 450 475 500 520 450 460 500 799 1121 979 817 698 768 691 424 459 343 362 245 257 282 1043 1465 1763 1541 1226 1348 1120 1238 1337 1116 937 564 571 625 471 1692 2289 2753 3268 . 2810 3074 2763 2336 2534 1956 >"'2065 ' 1586 1605 1817 1210 1245 811 614 4172 5862 7054 8056 6796 7428 6130 4954 4181 3541 . 3748 2989 3153 2507 1959 2020 1865 1593 6770 9159 11013 13072 11240 12297 11052 9344 7352 7825 6082 6345 5257 4514 4840 3811 3285 .2579 21097 29638 28216 24654 19739. 21572 24550 . 19074 20672 17850 18953 15687 16455 14200 10755 11062 7474 6371 The capacity figures given above are continuous discharge figures at the differential indicated: The actual pressure at the trap inlet and back pressure in the return fine should be used to obtain the pressure differential. : 772 ' Armstrong Machine Works Specialties, Heating differential the trap should be able to handle at least two and a quarter times the maximum amount of condensate that will be expected from the heater under normal operating conditions. When amount of condensate is not known--The amount of condensate from heating coils or other forms of direct radiation can be quickly determined by re ferring to table A showing the weight of steam condensed per hour per lineal foot of bare pipe or per square foot of heating sur face When the radiation is in greenhouses or dry kilns, multiply the above figures by two and when used for drying wet material such as brick and pottery, multiply by three. If blowers circulate air over the radiation, the figures should be multiplied by five. This will give the amount of con densate that will be obtained after the radiation has been brought up to tem perature, so before selecting a trap as out lined in the preceding section, allowances should be made for the extra amount of steam condensed in bringing the radiation up to temperature. TABLE A Condensate per Hour per Running Foot of Pipe Gauge Pressure Pounds 5 50 too - 150 200 Temperature Diff. Degrees F. 153 223 263 291 313 Pipe Sizes in Inches > tyl 2 3 4 5 6 8 0.16 0.28 0.36 0.43 0.50 0.21 0;38 0.41 0.59 0.68 0.25 0.45 0.59 0.71 0.81 0.3 0.63 0.84 1.00 1.16 0.45 0.79 1.05 1.26 1.45 0.54 0.97 1.28 1.54 1.74 0.64 1.14 1.51 1.82 2.09 0.82 1.47 1.94 2.35 2.69 Flat Surface or Larger'Pipe 10 12 Per Sq. Foot 1.01 1.80 2.39 2.89 3.30 1.19 2.13 2.82 3.40 3.91 0.34 ` 0.62 0.82 0.99 1.14 Installation of Armstrong Traps Whenever possible, Armstrong Traps should be installed below the radiation drained by the trap. This is of particular importance when traps are used on unit heaters. Small traps such as the Nos. 100, 30 and 31 are usually installed without a by-pass whereas the larger sizes generally are furnished with by-passes to facilitate the removal or examination of the traps. The by-pass should always be installed above the trap to prevent loss of prime in case the by-pass valve should develop a leak. Individual Traps--Best results will be obtained by using a trap on each steam heated unit. Even a slight difference in terminal pres sure between two units will cause one to fill up with air or water unless in dividual traps are used. Quick Vent Air Valves-- Since Armstrong Traps auto-' matically vent air, no quick relief air valves are absolutely necessary except in the case of large heaters when immediate temperature rise is imperative. The air handling capacity of the Nos. 30 and 31 Armstrong Traps is further increased by means of a thermic spring designed to hold the valve away from the seat as long as the trap is cold. When steam reaches the trap, the thermic spring straightens out and allow^ the valve to seat in the normal manner. Thermic springs can be furnished in all other sizes at slight extra cost. Whenever manufacturers recommend that their heaters be installed with a quick vent air valve, these recommendations should be fol lowed to the letter. However, once the heater has been brought up to tempera ture no more air will pass through the quick vent valve as air that comes.to the heater along with the steam will pass out through the Armstrong Trap at temperatures too high to cause the air relief valve to func tion; 773