What are Monel valves?
Monel is a nickel-copper and zinc alloy that was patented in 1906. Its considered a ‘natural alloy’ since it can be produced by refining ore containing nickel and copper in the ratio it is found in the natural nickel-copper ore. Monel is more expensive than stainless steel and highly resistant to corrosion. Its popular in marine applications, eyeglass frames, and musical instruments.
There is an excellent story of monel entitled ‘A Century of Monel Metal: 1906-2006′, which contains this account:
On January 30, 1906, U.S. patent 811,239 was issued to Ambrose Monell, then president of the three-year old Inco, for “a new and useful improvement in the manufacture-of nickel-copper alloys.” As is stated in the Monell patent, the process included smelting, “bessemerization,” calcining, and oxide reduction.While Browne’s plan to make German silver from the nickel/copper alloy was indeed possible, it was determined that the resulting alloy of about 70% nickel and 30% copper-the natural ratio of those elements in the matte ore-had some quite interesting properties as produced. The new alloy was silvery white, brighter than nickel, stronger than steel, and more resistant to corrosion in saltwater and sulfuric acid than bronze. In honor of the company’s president, the product was named “Monel” metal.
Read the full article here.
In WWI, the dog tags were Monel, and some were monel in WWII, but Monel was dropped as a requirement sometime during WWII. More information here.
So, a Monel valve is a valve made from a corrosive-resistant nickel-copper alloy.