Fittings, flanges, and unions for piping systems are constructed out of various types of metals. Forged carbon and alloy stainless steel fittings, flanges, and unions make up the largest segment of the market and accounted for about a quarter of sales as of the year 2000. This segment of the market consists of socket-weld or threaded-type fittings, flanges, and unions, which had an estimated market value of $220.4 million in 2000; butt-weld flanges accounted for about $125 million in sales; and butt-weld fittings, around $131 million in 2000.

Fittings and flanges made of copper, brass, or bronze represent the second-largest segment of this market. These products accounted for about 21% of sales in 2000. These fittings, flanges, and unions can be constructed of either cast brass or bronze, or wrought copper or alloy. Wrought copper and wrought copper alloy fittings, flanges, and unions made up the majority with $290 million in sales in 2000, or 71.4% of the copper, brass, or bronze fitting, flange, and union segment. Copper is an excellent conductor of electricity, while brass fittings are used for feed-water pipes where hard water makes steel pipes undesirable.

A significant percentage of metal fittings, flanges, and unions are made of a variety of different types of iron. Malleable iron encompasses the largest percentage, accounting for an estimated 11% of the entire market for metal fittings, flanges, and unions in 2000. Malleable iron is lighter in weight and resists shock, vibration, and rapid temperature changes. Gray iron accounted for an estimated 6.5% of the market for metal fittings, flanges, and unions in 2000. Gray iron is a form of cast iron, which is formed into graphite flakes that are imbedded within the metallic matrix. This allows the cast iron to readily absorb vibrations and it also possesses a self-lubrication feature. Ductile iron accounts for a very small percentage of the market.

Pipe coupling sales reached approximately $197 million in 2000, or 10% of the market. Couplings are used to connect two lengths of pipe, and they are generally made of wrought or cast metal or brass.

The market for metal fittings, flanges, and unions for piping systems is projected to grow at an average annual rate of 3.5% from 1998 to 2008, when it will reach a projected $2.6 billion.

Sidebar: U.S. Manufacturers' Sales Of Metal Fittings, Flanges, And Unions For Piping Systems, By Type

($ Millions)

1987 1992 1997 2000E

Gray Iron:

Fittings, Flanges,

and Unions 74.5 86.2 112.1 125.7

Grooved Fittings

and Couplings 8.9 9.9 NA NA

Malleable Iron:

Fittings and Flanges, Including

Reducers, Caps, etc. 118.2 101.3 138.4 154.7

Grooved Fittings

and Couplings 35.1 12.1 NA NA

Unions and

Union Fittings 27.4 32.5 45.1 50.3

Ductile Iron:

Fittings, Flanges,

and Unions 7.1 26.6 23.4 23.2

Grooved Fittings

and Couplings 3.6 22.1 19.5 17.4

Copper, Brass, or Bronze, Including Solder and Threaded:

Cast Brass or Bronze Fittings,

Flanges, and Unions 136.6 107.6 101.4 116.0

Wrought Copper and Wrought

Copper Alloy Fittings,

Flanges, and Unions 286.1 215.4 267.9 290.0

Cast Carbon and Alloy Steel Fittings,

Flanges, and Unions 25.0 29.7 48.7 58.0

Forged Carbon, Alloy, and Stainless Steel

Fittings, Flanges, and Unions, Socket-Weld

or Threaded Type 155.6 189.3 204.5 220.4

Flanges, Butt-Weld Types:

Carbon Steel 52.6 56.5 60.0 63.8

Alloy Steel 2.5 16.7 9.1 9.7

Stainless Steel 15.8 29.8 45.7 51.2

Fittings, Butt-Weld Types

Carbon Steel 82.1 38.2 20.5 22.2

Alloy Steel 3.6 17.2 9.3 9.7

Stainless Steel 19.1 57.2 89.4 99.0

Total $1,404.3 $1,356.5 $1,761.2 $1,933.3

E = Estimate

Source: U.S. Department of Commerce; Business Trend Analysts,

Commack, N.Y., phone: 631-462-5454.