stagnent water

[dandt]

Hello my plumbing is reasonable. I am about to remove part of a supply for a friend and can easily cap pipe as close as possible to a T junction. It is rarely mentioned but my question is...how great is the risk of stagnent water in a length of pipe which is capped and never run off periodically (eg if someone 'builds' over it). What length is considered a problem? I can imagine that water pressure is great enough to cycle water in a couple of cms worth but what about longer pipes?
Another example is in my house...new washine machine only uses cold pipe not hot supply, so there is a couple of feet of pipe with water which never moves, how often should it be run off?
Thanks
Derek

 

[bathstyle]

Let me consult my Reg book, Be right back

 

[bathstyle]

"A fitting or appliance may however , remain unconnected for a period not exceeding 60 days to allow a reasonable amount of time for the installer to obtain replacements for broken or damaged fittings or appliances"

 

[dextrous]

Hello my plumbing is reasonable. I am about to remove part of a supply for a friend and can easily cap pipe as close as possible to a T junction. It is rarely mentioned but my question is...how great is the risk of stagnent water in a length of pipe which is capped and never run off periodically (eg if someone 'builds' over it). What length is considered a problem? I can imagine that water pressure is great enough to cycle water in a couple of cms worth but what about longer pipes?
Another example is in my house...new washine machine only uses cold pipe not hot supply, so there is a couple of feet of pipe with water which never moves, how often should it be run off?
Thanks
Derek

Best to remove all of the dead leg bachto the tee if possible.
If your washing machine example refers to hot water in a dead leg, you're not likely to ingest it anyway. If you're referring to the cold water pipe, I assume you wash your clothes more frequently then once every two months

 

[dandt]

thanks but that hasnt really answered my question. There must be hundereds and thousands of situations (many unknown to a resident) in which a T junction is capped, rather than ...say replaced with an L shape, so that the reduntant pipe is completely removed.
Ps if it were my place I would replace more of the pipe in any case, but in this situation I dont want to start messing with an old fitting. I just want to cap the reduntant length close to the junction.
I might just transfer a now reduntant washine machine type tap so that there is the option to either run off periodically or to fit another appliance at a later date.

 

[dandt]

thanks dextrous
I posted my last comment before reading yours
Im fairly happy about how I'll do it at the friends. Out of curiosity does any document/regulation mention an actual length?
If not I'll just use common sense (we are only talking about a few cms anyway

 

[dextrous]

thanks dextrous
I posted my last comment before reading yours
Im fairly happy about how I'll do it at the friends. Out of curiosity does any document/regulation mention an actual length?
If not I'll just use common sense (we are only talking about a few cms anyway

There may be something that provides specifics which I haven't seen, but from memory they talk about removing deadlegs, which I suppose would mean allowing 0cm if one wanted to read it that way.

 

[bathstyle]

The Regs book doesn't specify any distance although the picture of the dead leg and the capped off dead leg does show a short stub of pipe, should I measure that stub?

 

[Nige F]

I`ll measure my stub if you measure yours