Step 4: Installing/Testing Gas Piping - HydroTherm HC-65 Installation Operation & Maintenance

STEP 4: INSTALLING & TESTING GAS PIPING
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 HC-120D 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:
120,000 Btu 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".
Maximum Capacity of Pipe in Cubic Feet of Natural Gas per Hour for Gas Pressures of
Nominal
Iron Pipe Internal
S i z e , Diameter
10
1 0
I n c h e s I n c h e s
1/4" 32
.326
3/8" 72
.493
1/2"
132
.622
3/4" 278
.824
1" 520
1.049
1-1/4" 1,050
1.380
1-1/2" 1,600
1.610
2" 3,050
2.067
2-1/2" 4,800
2.469
3" 8,500
3.026
4"
17,500
4.026
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquefied
Maximum Capacity of Pipe in Thousands of Btu per Hour of Undiluted Liquifi
Petroleum gases (at 11 Inches of Water Column Inlet Pressure)
Nominal
Iron Pipe
S i z e ,
I n c h e s
1/2"
3/4"
1"
1071
1-1/4" 2205
1-1/2" 3307
2" 6221
= 117.6 cu.ft. per hour
0.5 Psig or Less and a Pressure Drop of 0.3 Inch Water Column
(Based on a 0.60 Specific Gravity Gas)
20 30 40 50
2 0 3 0 4 0 5 0
22 18 15
49 40 34
92 73 63
190 152 130 115
350 285 245 215
730 590 500 440
1,100 890 760 670
2,100 1,650 1,450 1,270
3,300 2,700 2,300 2,000
5,900 4,700 4,100 3,600
12,000 9,700 8,300 7,400
Petroleum Gases (at 11 Inches Water Colum Inlet Pressure)
(Based on aPressure Drop of 0.5 Inch Water Column)
(Based of a Pressure Drop of 0.5 Inch Water Column)
10 20 30 40
1 0 2 0 3 0 4 0
275 189 152 129
567 393 315 267
732 590 504
1496 1212 1039
2299 1858 1559
4331 3465 2992
Length of Pipe, Feet
60 70 80
6 0 7 0 8 0
14 12 11 11
30 27 25 23
56 50 46 43
105 96 90
195 180 170
400 370 350
600 560 530
1,150 1,500 990
1,850 1,700 1,600 1,500
3,250 3,000 2,800 2,600
6,800 6,200 5,800 5,400
Length of Pipe, Feet
50 60 70 80
5 0 6 0 7 0 8 0
114 103 96 89
237 217 196 185
448 409 378 346
937 834 771 724
1417 1275 1180 1086
2646 2394 2205 2047
9
90 100 125 150
9 0 1 0 0 1 2 5
1 5 0
10 9 8 8
22 21 18 17
34
40 38 31
84 79 72 64
160 150 130 120
320 305 275 250
490 460 410 380
930 870 780 710
1,400 1,250 1,130
2,500 2,200 2,000
4,500
5,100 4,100
90 100 125 9 0 1 0 0 1 2 5 150
1 5 0
83 78 69 63
173 162 146 132
275
322 307 252
677 630 567 511
1023 967 866 787
1921 1811 1606 1498
175 200
1 7 5
2 0 0
7 6
15 14
28 26
59 55
110 100
225 210
350 320
650 610
1,050 980
1,850 1,700
3,800 3,500
FIGURE 1.16