Copper Brazed Plate

Anything that dissolves copper pipe will dissolve the braze joints, and those joints are what hold the block together. Watch for water treatment programs that use ammonia compounds, sulfide-bearing well water, low pH and aggressive softened water. A recent water analysis settles most cases, and where it shows a problem, nickel braze is the safer selection.

In most installations it is, because the water already runs through copper piping in the same building. The plates are 316 stainless, and the braze is a small exposed area at each contact point. Where local water is known to pit copper tube or leave blue staining, the same chemistry will shorten the life of the braze, so mention it.

Fresh inhibited glycol is fine and is one of the most common copper brazed duties. The risk comes later, when the inhibitor is spent and the glycol turns acidic as it ages and oxidizes. That acidic fluid attacks copper from the inside, so test the loop each year and top up the inhibitor before the pH drifts low.

On a closed, treated loop it is good practice, and on any open loop it is close to mandatory. Weld slag, pipe scale and gasket fragments from commissioning are the usual culprits, and one piece lodged at a port can block a set of channels permanently. Fit the strainer where it can be cleaned without draining the unit, with gauges either side to show when it loads up.