On Sat, 2 Jan 2010 11:04:29 -0800, you wrote: >10 >years ago McLendon's began carring ball valves made in China. They had both >types, side by side on the shelf. US =$12, China = $6. I was extending my >greenhouse at the time and bought 4 valves Made in China. They have all >failed that winter. I replaced them with US made valves. I have yet to have >a US valve fail. > >Here is the failure mode. Even though the system is drained the walls of the >Chinese valves freeze and crack. This is because of voids and porosity of >the castings.
Dezincification failures are a big problem with cheap fittings especially if they have been in use for some time in acidic water, and it's not just a Chinese thing. I've seen it on European and USA made fittings. The "American" fittings are probably DZR Brass, the Chinese are probably any old recycled Brass, likely the shavings Matt was talking about :) Good quality brass fittings are made from CZ132 Brass, which needs heat treating to 500C or so after forging to resist dezincification. You can buy good Chinese fittings, just as you can buy bad American ones. If you do suffer from dezincification buying from a good plumbers supply shop or marine chandlers is a safer bet, you'll pay more, but they should be able to supply decent fitting that will last a lifetime. Steve Blackmore -- ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
