HydroTherm EW2-1203, Installation, Operation & Maintanance Manual

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FIGURE 1.16
PROCEDURE A: Select gas pipe size which will result in a pressure drop of less than 0.3" W.C.
for natural gas or 0.5" W.C. for propane, following example below.
Example: Boiler Model EW-125 is to be installed. Distance from existing gas meter to installation site is 20 ft.
What pipe size must be used? Local utility indicates heating value of natural gas being supplied is 1020 Btu per
cu.ft. Determine cubic feet of gas per hour for above boiler model:
125,000 Btu per hour
= 122.5 cu.ft. per hour
1020 Btu per cu.ft.
1. Find 20 ft. in upper portion of the table for natural gas under “Length of Pipe, Feet” heading.
2. Moving down the column, match required capacity. Higher capacity acceptable. In our case it is 190 cu.ft.
3. Move to left-hand column “Nominal Iron Pipe Size, Inches”; read required pipe size. In our case it is 3/4
4. Take into account the effects of pipe fittings when determining the correct pipe size.
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STEP 4: INSTALLING & TESTING GAS PIPING
➤
10 20 30 40 50 60 70 80 90 100 125 150 175 200
10 20 30 40 50 60 70 80 90 100 125 150
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquefied
Petroleum gases (at 11 Inches of Water Column Inlet Pressure)
(Based of a Pressure Drop of 0.5 Inch Water Column)
.326 32 22 18 15 14 12 11 11 10 9 8 8 7 6
.493 72 49 40 34 30 27 25 23 22 21 18 17 15 14
.622 132 92 73 63 56 50 46 43 40 38 34 31 28 26
.824 278 190 152 130 115 105 96 90 84 79 72 64 59 55
1.049 520 350 285 245 215 195 180 170 160 150 130 120 110 100
1.380 1,050 730 590 500 440 400 370 350 320 305 275 250 225 210
1.610 1,600 1,100 890 760 670 600 560 530 490 460 410 380 350 320
2.067 3,050 2,100 1,650 1,450 1,270 1,150 1,500 990 930 870 780 710 650 610
2.469 4,800 3,300 2,700 2,300 2,000 1,850 1,700 1,600 1,500 1,400 1,250 1,130 1,050 980
3.026 8,500 5,900 4,700 4,100 3,600 3,250 3,000 2,800 2,600 2,500 2,200 2,000 1,850 1,700
4.026 17,500 12,000 9,700 8,300 7,400 6,800 6,200 5,800 5,400 5,100 4,500 4,100 3,800 3,500
1/4"
3/8"
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"
2-1/2"
3"
4"
Nominal
Iron Pipe
Size,
Inches
Internal
Diameter,
Inches
Length of Pipe, Feet
Maximum Capacity of Pipe in Cubic Feet of Natural Gas per Hour for Gas Pressures of
0.5 Psig or Less and a Pressure Drop of 0.3 Inch Water Column
(Based on a 0.60 Specific Gravity Gas)
Nominal
Iron Pipe
Size,
Inches
Length of Pipe, Feet
275 189 152 129 114 103 96 89 83 78 69 63
567 393 315 267 237 217 196 185 173 162 146 132
1071 732 590 504 448 409 378 346 322 307 275 252
2205 1496 1212 1039 937 834 771 724 677 630 567 511
3307 2299 1858 1559 1417 1275 1180 1086 1023 967 866 787
6221 4331 3465 2992 2646 2394 2205 2047 1921 1811 1606 1498
1/2"
3/4"
1"
1-1/4"
1-1/2"
2"