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what are steel pipes used for

Publish Time: 2022-04-02 Origin: Site

Steel Pipes

Steel pipes are the most commonly used pipes in water supply systems. They are also used in pipelines for natural gas, and sewerage systems. Although comparatively expensive to other pipes, they hold the advantage of being able to withstand high pressures and are available in more convenient lengths, and can also be welded easily, thereby resulting in lower installation and transportation costs. These types of pipes are highly efficient and can be used in small diameters as needed and are 100% recyclable compared to other materials. The pipes can further be melted down and turned into other usable material in industry. Furthermore, the high strength of these pipes and resistance to damage caused by human errors, tree roots, and extreme weather conditions make these pipes the ideal choice for most water and sewerage supply systems.

The disadvantages of steel pipes include thermal conductivity, which is very poor as there is a difference in heat transfer. These types of pipes are usually bonded with aluminum or copper to increase thermal conductivity and improve heat transfer. Cost is another issue, as these pipes are expensive and this is guided by the misconception of being a one-time purchase. However, steel pipes are difficult to fabricate and lack the malleable qualities that other materials have, therefore repairs and replacements of steel pipes are extra difficult

Steel pipes

Steel pipes to BS 1387 are normally specified in the nominal bore sizes given in Table 1. Finishes can be black or galvanised, the latter being preferred for corrosion resistance.

TABLE 1. Nominal bore size steel tubes to BS 1387

Nominal size	Actual bore				Approximate o.d.
	Medium		Heavy
in	in	mm	in	mm	in	mm
1/8	0.226	5.77	0.178	4.52	13/32	10.3
1/4	0.338	8.59	0.290	7.37	17/32	13.5
3/8	0.476	12.09	0.428	10.87	11/16	17.5
1/2	0.623	15.82	0.575	14.60	27/32	21.5
3/4	0.839	21.31	0.791	20.09	1.1/16	27
1	1.060	26.92	0.996	25.30	1.11/32	34
1.1/4	1.401	35.59	1.337	33.96	1.11/16	43
1.1/2	1.633	41.48	1.569	39.85	1.29/32	48
2	2.066	52.48	2.002	50.80	2.3/8	60

Steel pipes are normally used with threaded connections. Above 65 mm nominal bore, welded fittings to BS 1965 are recommended, although cast iron pipes with integral flanges or steel pipes with welded-on flanges may be used. In sizes smaller than 65 mm malleable iron fittings conforming to BS 143 and BS 1256 may be used for pressures up to 10 bar.

Screwed connections, to BS 21, are restricted to metallic tubes with thick walls.