Watts MG - Manual (Page 3)

Valve Seat Pressure 1 ⁄ 4
1 ⁄ 2 1 2 5 10 15 20 30 50
Orifice Differential
Size Model Diameter Lat. Ht. Value 969.8 969.3 968 966 961 952 945 939 929 912
Lbs. Cond./Hr. 70 100 140 200 210 220 230
3 ⁄
4
6G-15 MBH 68 97 136 193 202 209 217
EDR 282 404 566 804 841 870 904
Lbs. Cond./Hr. 175 250 350 500 525 550 575
1 7G-15 MBH 170 242 339 483 505 524 543
EDR 708 1008 1413 2012 2104 2183 2263
Lbs. Cond./Hr. 425 600 850 1200 1260 1320 1280
1 1 ⁄
4
8G-15 MBH 412 582 823 1159 1211 1257 1304
EDR 1717 2423 3428 4830 5045 5236 5434
Lbs. Cond./Hr. 850 1200 1700 2400 2520 2640 2760
1 1 ⁄ 2 91G-15 MBH 824 1163 1646 2318 2422 2513 2608
EDR 3435 4847 6857 9660 10091 10472 10868
Lbs. Cond./Hr. 1775 2500 3550 5000 5250 5500 5750
2 101G-15 MBH 1721 2423 3436 4830 5045 5236 5434
EDR 7172 10096 14318 20125 21021 21817 22641
2 111MG-15
21 ⁄
32 Lbs. Cond./Hr. 2200 2900 3920 5200 7600 10100 12000
MBH 2133 2811 3795 5023 7304 9615 11340
1 7MG-30 1 ⁄
8 Lbs. Cond./Hr. 95 127 170 228 335 445 530 600 700
MBH 92 123 165 220 322 424 501 563 650
1 1 ⁄
4
8MG-30 5 ⁄
32 Lbs. Cond./Hr. 156 210 280 375 550 740 870 980 1160
MBH 151 204 271 362 529 704 822 920 1078
1 1 ⁄ 2 91MG-30
19 ⁄
64 Lbs. Cond./Hr. 525 700 940 1250 1850 2450 2930 3300 3900
MBH 509 679 910 1208 1778 2332 2769 3099 3623
2 101MG-30 11 ⁄
32 Lbs. Cond./Hr. 670 890 1180 1580 2340 3120 3700 4150 4900
MBH 650 863 1142 1526 2249 2970 3497 3897 4552
2 111MG-30 15 ⁄
32 Lbs. Cond./Hr. 1300 1750 2340 3120 4600 6100 7200 8200 9700
MBH 1261 1696 2265 3014 4421 5807 6804 7700 9011
3 ⁄ 4 6MG-50
3 ⁄
32 Lbs. Cond./Hr. 52 69 92 122 180 240 285 320 380 470
MBH 50 67 89 118 173 228 269 300 353 429
1 7MG-50 7 ⁄
64 Lbs. Cond./Hr. 81 108 143 190 280 375 440 500 590 730
MBH 79 105 138 184 269 357 416 470 548 666
1 1 ⁄
4
8MG-50 1 ⁄
8 Lbs. Cond./Hr. 102 138 182 245 355 475 565 630 750 920
MBH 99 134 176 237 341 452 534 591 697 839
1 1 ⁄ 2 91MG-50
15 ⁄
64 Lbs. Cond./Hr. 360 480 640 860 1260 1680 2000 2250 2670 3300
MBH 349 465 620 831 1211 1599 1890 2113 2480 3010
2 101MG-50 9 ⁄
32 Lbs. Cond./Hr. 460 610 820 1100 1600 2140 2520 2841 3350 4150
MBH 446 591 794 1063 1538 2037 2381 2667 3112 3785
2 111MG-50 21 ⁄
64 Lbs. Cond./Hr. 630 850 1140 1520 2220 2950 3500 3950 4700 5800
MBH 611 824 1104 1468 2133 2808 3308 3709 4366 5290
The basic capacity ratings are expressed in pounds conden-
sate per hour at various pressure differentials.
For ease of trap selection the tables also give the heating
value in MBH of the steam condensed. This is arrived at by
multiplying the condensate rating by the appropriate Latent
Heat Value and dividing by 1,000 to determine MBH.
Capacities are also expressed in square feet Equivalent
Direct Radiation. This is determined by dividing the heating
capacity in BTU/Hr. (MBH x 1,000) by 240 BTU/Hr./Square
Foot Equivalent Direct Radiation.
Example:
Select a trap for a Unit Heater with a heating capacity of 170
MBH operating on a 5 psi line. A 2 to 1 capacity factor is desired.
MBH rating for selection purposes =
2 x 170 = 340 MBH. Read down 5 psi
column and select the smallest trap whose
MBH rating exceeds 340 MBH.
The 1" 7G has a capacity of 505 MBH,
or 525 pounds of condensate per hour on
2,104 square feet Equivalent Direct
Radiation. 1" 7G is the correct trap for
this application.
Note: The condensate capacities for GF or MGF traps are the same as shown for G or MG float and thermostatic traps and selection should
be made in the same manner.
**Ratings are in accordance with the recommended standards adopted by the Steam Heating Equipment Manufacturers Association. Select trap directly from
table for the lowest differential that may exist in the system. Traps may be applied directly and no safety factor need be applied.
Maximum Trap Capacities
Pounds Condensate Per Hour, MBH, and Square Feet EDR
**Ca
pacities According
to
Recommended Shema Standards