The following remarks were made regarding the article “Dos and donts of hydronic system design,” written by John Siegenthaler, principal, Appropriate Designs, published in the July 2020 issue of Plumbing & Mechanical:
Thanks, John, for the great article. I'd like to add a pet peeve of mine. I'm a mechanical engineer. Our specifications always required a dielectric connection (dielectric union or flanged) at the junction of brass valves or fittings with iron pipe. But I've seen frequent installations, mainly light commercial/residential, where there is a brass valve screwed onto iron pipe and the joint is rusted and leaking. Pipe dope or pipe tape is not a good enough separation in this case. It'll get you through the warranty period, but at some point down the road, before they have to replace the boiler you installed, your customer will be paying for a repair of that joint.
Mark Baumann // Oneida, New York