Maxims and Instructions for the Boiler Room / Useful to Engineers, Firemen & Mechanics; Relating to Steam Generators, Pumps, Appliances, Steam Heating, Practical Plumbing, etc.

by N. Hawkins

Table 3. NUMBER OF BRACES REQUIRED, AT 100 LBS. PRESSURE.

Height from tubes to shell.	DIAMETER OF BOILER IN INCHES.
	36	42	48	54	60	66	72
15	3.5
16	4.0
17	4.5	5.0
18		5.6	6.2	6.7
19		6.2	6.9	7.5
20		6.8	7.5	8.2	8.9
21			8.2	9.0	9.6
22			8.9	9.8	10.5
23				10.5	11.3	12.1
24				11.3	12.2	13.1
25				12.1	13.1	14.0
26				12.9	14.0	15.0	15.9
27				13.7	14.9	16.0	16.9
28					15.8	16.9	18.0
29					16.7	17.9	19.1
30					17.6	18.9	20.2
31						19.9	21.3
32						21.0	22.4
33							23.5
34							24.9

In Table 2 this calculation has been made for all sizes of boilers that are ordinarily met with. The area to be braced has been calculated as above in each case, the two-inch strip above the tubes, and the three-inch strip around the shell being taken into account. As an example of its use, let us suppose that upon measuring a boiler we find that its diameter is 54 inches, and that the distance from the upper tubes to the top of the shell is 25 inches. Then by looking in the table under 54″ and opposite 25″ we find 714, which is the number of square inches that requires staying on each head.

BOILER TUBES.

Table.

Dimensions of Lap Welded Boiler Tubes.

Size outside diameter.		Wire Gauge.	Weight per foot.
1	inch.	15	0.708
11⁄4	„	15	0.9
11⁄2	„	14	1.250
13⁄4	„	13	1.665
2	„	13	1.981
21⁄4	„	13	2.238
21⁄2	„	12	2.755
23⁄4	„	12	3.045
3	„	12	3.333
31⁄4	„	11	3.958
31⁄2	„	11	4.272
33⁄4	„	11	4.590
4	„	10	5.320
41⁄2	„	10	6.010
5	„	9	7.226
6	„	8	9.346
7	„	8	12.435
8	„	8	15.109
9	„	71⁄2
10	„	61⁄2

The above is the regular manufactures’ list of sizes and weights.

Note.