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

PIPES AND PIPING.

Next in importance after the skill necessary for the steam generator and the engine, is the proper arrangement and care and management of the pipes and valves belonging to a steam plant.

It is the first thing an engineer does in taking charge of a new place, to ascertain the exact course and operation of the water, steam, drain and other pipes.

Examiners for licensing marine and land engineers base their questions much more to ascertain the applicant’s knowledge of piping than is generally known; hence the importance of the “points” in the succeeding pages relating to this subject.

Pipes are used for very many purposes in connection with the boiler room, and of course vary in size, in material and in strength, according to the purposes for which they are designed. There are pipes for conveying and delivering illuminating gas; pipes for conveying and delivering drinking water, and for fire purposes; pipes for draining and carrying off sewage and surface water; pipes for delivering hot water under high pressure, for heating purposes and power; pipes for delivering live steam under pressure, for heating purposes and power; pipes for delivering compressed air, for purposes of power and ventilation; pipes for conveying mineral oils, etc.

In Figs. [111], [112] [113] and [114] are given approximate sizes of gas pipe and boiler tubes, taken from the catalogue of one of the oldest steamfitting establishments in the country. It will be observed that the size of gas pipe is computed from the internal diameter, while boiler tubes are estimated from the outside: thus, 3 in. gas pipe has an external diameter of 3¹⁄₂ inches, while 3 in. boiler tubes have an outside diameter of 3 inches only. It may be noted that boiler-tubes are made much more accurately as to size than gas pipe; this is especially true of the outside surfaces which are much smoother in one case than in the other.

BOILER TUBES.

Fig. 113.

Fig. 114.

SURFACES AND CAPACITIES OF PIPES.

Sizes of Pipes.	1⁄2 in.	3⁄4 in.	1 in.	11⁄4 in.	11⁄2 in.	2 in.
1. Outside circumferences of pipes in inches	2.652	3.299	4.136	5.215	5.969	7.461
2. Length of Pipe in feet to give a square foot of outside surface	4.52	3.63	2.90	2.30	2.01	1.61
3. Number of square feet of outside surface in ten lineal feet of Pipe	2.21	2.74	3.44	4.34	4.97	6.21
4. Cubic in. of internal capacity in ten lineal feet of pipe	36.5	63.9	103.5	179.5	244.5	402.6
5. Weight in lbs. of water in ten lineal feet of pipe	1.38	2.31	3.75	6.5	8.8	14.6
Sizes of Pipes.	21⁄2 in.	3 in.	31⁄2 in.	4 in.	41⁄2 in.	5 in.
1. Outside circumferences of pipes in inches	9.932	10.99	12.56	14.13	15.70	17.47
2. Length of Pipe in feet to give a square foot of outside surface	1.32	1.09	.954	.849	.763	.686
3. Number of square feet of outside surface in ten lineal feet of Pipe	7.52	9.16	10.44	11.78	13.09	16.56
4. Cubic in. of internal capacity in ten lineal feet of pipe	573.9	886.6	1186.4	1527.6	1912.6	2398.8
5. Weight in lbs. of water in ten lineal feet of pipe	20.8	32.1	43.6	55.4	69.3	86.9

Pipe manufactured from double thick iron is called X-strong pipe, and pipe made double the thickness of X-strong is known as XX-strong pipe. Both X-strong and XX-strong pipe are furnished plain ends—no threads, unless specially ordered.

The table “Data relating to iron pipe” will be found especially useful to the engineer and steam fitter. The size of pipes referred to in the table range from ¹⁄₈ to 10 inches in diameter. In the successive columns are given the figures for the following important information:

1. Inside diameter of each size.
2. Outside diameter of each size.
3. External circumference of each size.
4. Length of pipe per square foot of outside surface.
5. Internal area of each size.
6. External area of each size.
7. Length of pipe containing one cubic foot.
8. Weight per foot of length of pipes.
9. Number of threads per inch of screw.
10. Contents in gallons (U. S. measure) per foot.
11. Weight of water per foot of length.

DATA

Relating to Iron Pipe.

Inside Diameter.	Outside Diameter.	External Circumference.	Length of Pipe per sq. ft. of Outside Surface.	Internal Area.	External Area.
Inches.	Inches.	Inches.	Feet.	Inches.	Inches.
1⁄8	.40	1.272	9.44	.012	.129
1⁄4	.54	1.696	7.075	.049	.229
3⁄8	.67	2.121	5.657	.110	.358
1⁄2	.84	2.652	4.502	.196	.554
3⁄4	1.05	3.299	3.637	.441	.866
1	1.31	4.134	2.903	.785	1.357
11⁄4	1.66	5.215	2.301	1.227	2.164
11⁄2	1.9	5.969	2.01	1.767	2.835
2	2.37	7.461	1.611	3.141	4.430
21⁄2	2.87	9.032	1.328	4.908	6.491
3	3.5	10.996	1.091	7.068	9.621
31⁄2	4.	12.566	.955	9.621	12.566
4	4.5	14.137	.849	12.566	15.904
41⁄2	5.	15.708	.765	15.904	19.635
5	5.56	17.475	.629	19.635	24.299
6	6.62	20.813	.577	28.274	34.471
7	7.62	23.954	.505	38.484	45.663
8	8.62	27.096	.444	50.265	58.426
9	9.68	30.443	.394	63.617	73.715
10	10.75	33.000	.355	78.540	90.792
Inside Diameter.	Length of Pipe containing one Cubic Foot.	Weight per ft. of Length.	No. of Threads per inch of Screw.	Contents in Gallons[A] per foot.	Weight of Water per foot of Length.
Inches.	Feet.	Lbs.			Lbs.
1⁄8	2500.	.24	27	.0006	.005
1⁄4	1385.	.42	18	.0026	.021
3⁄8	751.5	.56	18	.0057	.047
1⁄2	472.4	.84	14	.0102	.085
3⁄4	270.	1.12	14	.0230	.190
1	166.9	1.67	111⁄2	.0408	.349
11⁄4	96.25	2.25	111⁄2	.0638	.527
11⁄2	70.65	2.69	111⁄2	.0918	.760
2	42.36	3.66	111⁄2	.1632	1.356
21⁄2	30.11	5.77	8	.2550	2.116
3	19.49	7.54	8	.3673	3.049
31⁄2	14.56	9.05	8	.4998	4.155
4	11.31	10.72	8	.6528	5.405
41⁄2	9.03	12.49	8	.8263	6.851
5	7.20	14.56	8	1.020	8.500
6	4.98	18.76	8	1.469	12.312
7	3.72	23.41	8	1.999	16.662
8	2.88	28.34	8	2.611	21.750
9	2.26	34.67	8	3.300	27.500
10	1.80	40.64	8	4.081	34.000
[A] The Standard U. S. gallon of 231 cubic inches.

The division of process in the manufacture of pipe, takes place at 1¹⁄₄ inch, 1¹⁄₄ inch and smaller sizes being called butt-welded pipe, and 1¹⁄₂ inch and larger sizes being known as lap-welded pipe; this rule holds good for standard, X-strong and XX-strong.