Iron Pipe Size (IPS) refers to an old pipe sizing system still in use by some industries, including major PVC pipe manufacturers, as well as some legacy drawings and equipment.
The iron pipe size standard came into being early in the 19th century and remained in effect until after World War II. The IPS system was primarily used in the US and the United Kingdom. In the 1920s, the Copper Tube Size (CTS) standard was combined with the IPS standard.
During the IPS period, pipes were cast in halves and welded together, and pipes' dimensions were sized by reference to the inside diameters of the pipes . The inside diameters under IPS were roughly as we know them today under the Ductile Iron Pipe Standard (DIPS) and Nominal Pipe Size (NPS) Standards, and some of the wall thicknesses were also retained with a different designator. In 1948, the DIPS came into effect, when greater control of a pipe's wall thickness was possible.
CTS diameter always specifies the OD of a tube, where pipe diameter specifications only approximate the pipe ID for sizes of 12 inch or less, and STD wall thickness. The IPS number (reference to an OD) is the same as the NPS number, but the schedules were limited to Standard Wall (STD), Extra Strong, (XS) and Double Extra Strong (XXS). STD is identical to SCH 40 for NPS 1/8 to NPS 10, inclusive, and indicates .375" wall thickness for NPS 12 and larger. XS is identical to SCH 80 for NPS 1/8 to NPS 8, inclusive, and indicates .500" wall thickness for NPS 8 and larger. Different definitions exist for XXS, but it is generally thicker than schedule 160.
Famous quotes containing the words iron, pipe and/or size:
“Ay, they heard his foot upon the stirrup,
And the sound of iron on stone,
And how the silence surged softly backward,
When the plunging hoofs were gone.”
—Walter De La Mare (1873–1956)
“On a cloud I saw a child,
And he laughing said to me,
“Pipe a song about a Lamb”;
So I piped with merry chear.
“Piper pipe that song again”—
So I piped, he wept to hear.
“Drop thy pipe thy happy pipe
Sing thy songs of happy chear”;
So I sung the same again
While he wept with joy to hear.”
—William Blake (1757–1827)
“There are obvious places in which government can narrow the chasm between haves and have-nots. One is the public schools, which have been seen as the great leveler, the authentic melting pot. That, today, is nonsense. In his scathing study of the nation’s public school system entitled “Savage Inequalities,” Jonathan Kozol made manifest the truth: that we have a system that discriminates against the poor in everything from class size to curriculum.”
—Anna Quindlen (b. 1952)