Talk:Pressure vacuum breaker

I was hoping to find out more about vacuum breakers as used in hot water geysers. As far as I know, these have the dual role of preventing water being siphoned from the geyser into the mains water supply, although this is better done with a non-return valve, and, they prevent a partial vacuum being created in the geyser if, for example, the water is drained out when there is no supply and/or the supply valve is closed. Some of the cheaper geysers I have worked on are lined with a fibreglass lining that collapses and perforates if the vacuum valve isn't working/fitted, resulting in a leaking geyser and all the accompanying problems.217.113.74.161 17:10, 15 June 2007 (UTC)[reply]

I don't know exactly what you just described, but if anyone does, I think adding more applications to the wiki page about the pressure vacuum breakers, that would be great info.--Ivangiesen (talk) 12:58, 15 June 2020 (UTC)[reply]

Pressure Vacuum Breaker Flow Diagrams[edit]

Hi all, just posted nearly the same section for the atmospheric vacuum breaker device talk section. Same question here: does anyone think that having some flow diagrams describing the different operating modes of the device would be helpful? (Eg. normal flow, backflow, backflow leakage, etc.)? I think a lot more good and useful information could be added to this article.--Ivangiesen (talk) 12:56, 15 June 2020 (UTC)[reply]

Cost?[edit]

Why so much variation in cost of vacuum breaker/backflow preventers (eg $3-35)? Which type is needed for home/yard use? Is freeze-resistance important? JdelaF (talk) 20:59, 15 April 2023 (UTC) JdelaF (talk) 20:59, 15 April 2023 (UTC)[reply]