Although efforts have been made to coordinate U.S. standards with those of foreign standards-making bodies, surprisingly few standards have crossed borders intact. Still, it pays to know what choices there are, especially in light of the fact that the U.S. no longer overwhelmingly dominates the standards creation scene.
Imagine driving down the highway and seeing two different speed limit signs side by side. Which do you adhere to, especially in light of the fact that ignorance of the law is no excuse! This analogy is similar to what the PVF industry faces today: Which standard do you pick when multiple standards exist for the same product or procedure?
Twenty-five years ago, the valve world was regulated by the many American-produced valve standards. Although other national standards organizations in countries such as Great Britain, Germany and Japan existed, their influence was nowhere near that of the American Petroleum Institute (API), American Society of Mechanical Engineers (ASME), Manufacturers Standardization Society of the Valve & Fitting Industry (MSS), and other red, white and blue standards development groups.
However, as the scope of domestic U.S. manufacturing has narrowed, the influence of non-U.S. standards development organizations has broadened, most notably in the form of the International Organization for Standardization (ISO). Today, somewhat of a clash exists between the traditional U.S. standards and the emerging strength of ISO’s valve standards. The result is an uneasy truce as the world’s process industries and valve manufacturers sort out which valve standards they want to follow.
BACKGROUND OF U.S. VALVE STANDARDS
United States valve standards have a long history, dating back to the first quarter of the 20th century. The first standard to make reference to valves was the Boiler and Pressure Vessel Code, published by ASME in 1915. Although it did not go into detail on design, this boiler document referenced safety relief valves. The creation of MSS in 1924 opened the door for a number of additional valve-related standards, beginning with the organization’s first document on radiator valves in 1925. In fact, MSS created most valve-related standards from the 1920s until WWII.
In 1939, the American Standards Association (ASA) published the first edition of B16e, a document that would later morph into ASME’s B16.34, Valves, Flanged, Threaded and Welding End, which is the still the most popular valve design standard in use today. API published its first refinery valve standard in 1949, with the initial edition of API 600, API Standard on Flanged and Welding End Steel Wedge-Gate and Plug Valves for Refinery Use. This standard has been revised many times and is still very much in use, although its title has changed to Bolted Bonnet Steel Gate Valves for Petroleum and Natural Gas Industries.
Since the 1940s, U.S. valve standards activity has boomed with dozens of documents created by all the major standards-making bodies, plus additional offerings by relative newcomers to the valve standard scene—The Instrument Society of America (ISA) and the American Water Works Association (AWWA).
Until about 1990, American valve standards were the unchallenged leader worldwide. But as the domestic American valve manufacturing base began to erode, the previously unopposed dominance of American valve standards was challenged. The emergence of huge new markets in the Far East, as well as new manufacturers springing up worldwide, resulted in a cry for valve standards that were more international in flavor, which meant primarily ISO-created documents.