Re: RGS #20

Ideally braces should have no slop in tension when installed, but they should also have no preload on them either. When we do the final fit we will get as close to this condition as possible.

While boilers shells seem rigid, they actually move quite a bit. My preference is to minimize this by controlling the slop rather than putting tension on the braces. Slop is a known quantity while tension is not. As an example, one brace was short and it was heated to get the pin in for the trial fit for alignment. It was 1/8" short so it had considerable preload that would only be aggravated with pressure. This brace was forge lengthened. If we can control the slop to within .010" which isn't too difficult, we will end up with a more uniform load on the braces. If the sheet needs to flex an extra .010" it isn't a big deal.