What happens to flux in cold water pipes?

[Monty_jon]

What happens to flux in cold water pipes does it just get washed away when the piping is used, and how long does it take to flush it out?

Can’t imagine it would be healthy drinking water with flux?

 

[oldbuffer]

1. If soldered correctly with flux only applied to the pipe, then minimal if any flux inside pipework.
2. How long it takes to flush out will depend on flux used. If grease based, could be a while, if etch based, fairly quick.
3. Only real issue is mains connected pipes, as you shouldn't be drinking from tank fed pipes anyway. With minimum pressure of around 0.9 bar flow rate should be good, so will dissolve / flush out quickly.
4. Impact on digestive system must also depend on type of flux. Shouldn't think its healthy but doesn't seem to be an issue, probably because flushed out before use.

 

[BlueLoo]

There are no soldered fittings in my house at all.
Everything is compression fit. This is as recommended by the Boiler OEM on the heating side.
Also, all of my Piping, save a few feet around the tank (?) and the boiler is PEX.

I can't help but wonder why soldered fittings/copper pipe are still used, if at all on domestic potable water services.

 

[bernardgreen]

I can't help but wonder why soldered fittings/copper pipe are still used, if at all on domestic potable water services.

one reason is that copper is germicidal https://www.smithsonianmag.com/science-nature/copper-virus-kill-180974655/

When researchers reported last month that the novel coronavirus causing the COVID-19 pandemic survives for days on glass and stainless steel but dies within hours after landing on copper, the only thing that surprised Bill Keevil was that the pathogen lasted so long on copper.

Page 9 of 34 from https://pdfs.semanticscholar.org/8f5f/d0ca3e659edf18b21e31c0f144fb69668b3e.pdf

Many studies have demonstrated that some PEX pipes increase biofilm growth [59,140,147] and OP growth [59,140] relative to copper and iron. Unfortunately, it is unclear how general these effects are because the formulation of PEX used (e.g., PEX-b) varies from one manufacturer to another [170,172] and is typically proprietary and thus not cited in the available literature [59,140,147]. An experiment in the Netherlands using small-scale recirculating water heater systems (eight gallon tanks) connected to copper or PEX pipes (19.4 ft) attributed over three times higher Legionella bulk water levels in PEX pipe systems as compared to copper pipe systems although the authors did not determine if the difference was due to copper antimicrobial effects or leached organic carbon growth-promotion [140].

 

[oldbuffer]

1. Copper is recyclable and lasts indefinitely. Plastic is an oil based product, so made from fossil fuels. It can be recycled, but not economically unless a single material.
2. A soldered joint, properly made, relies on the amalgam of solder and copper and nothing else. Plastic relies on rubber O rings which can degrade over time.
3. Copper is much less susceptible to rodent attack.

 

[Madrab]

All fluxes used these days for potable water must be water soluble, once flushed for a minute it should be fully clean.

Copper v plastic .... This is a long long standing argument that's done to death - There are pro's and cons for both and each has it's place IMO

Copper is resistant to vermin and mechanical damage. Copper is fully recyclable. Copper is more heat resistant, longer lifespan, is best material for use outdoors, is more resistance to solvents, etc .......
Plastic also has it's benefits though - Cheaper (pipe not fittings), ease of install , quicker to install, more resistant to corrosives, more DIY'able (earns me more money when it goes DIY wrong ), etc .....

Soldering though is by far the best and most long term reliable and trusted connecting method for copper pipe, especially if it is to be inaccessible. Once soldered properly, soldered copper is then considered a permanent part of the pipe. Compression and push fit aren't.

Which boiler OEM recommends compression and where is considered to be on the heating side?

 

[BlueLoo]

one reason is that copper is germicidal https://www.smithsonianmag.com/science-nature/copper-virus-kill-180974655/

When researchers reported last month that the novel coronavirus causing the COVID-19 pandemic survives for days on glass and stainless steel but dies within hours after landing on copper, the only thing that surprised Bill Keevil was that the pathogen lasted so long on copper.

Page 9 of 34 from https://pdfs.semanticscholar.org/8f5f/d0ca3e659edf18b21e31c0f144fb69668b3e.pdf

Many studies have demonstrated that some PEX pipes increase biofilm growth [59,140,147] and OP growth [59,140] relative to copper and iron. Unfortunately, it is unclear how general these effects are because the formulation of PEX used (e.g., PEX-b) varies from one manufacturer to another [170,172] and is typically proprietary and thus not cited in the available literature [59,140,147]. An experiment in the Netherlands using small-scale recirculating water heater systems (eight gallon tanks) connected to copper or PEX pipes (19.4 ft) attributed over three times higher Legionella bulk water levels in PEX pipe systems as compared to copper pipe systems although the authors did not determine if the difference was due to copper antimicrobial effects or leached organic carbon growth-promotion [140].

Brass door handles etc.
Good points.

During recent renovations to my plumbing, my PEX lines were spotless, however, the copper tank and any brass fittings were scaled with calcium and verdigris (and hemp and hardened snot from the plumbers jointing )

 

[BlueLoo]

Which boiler OEM recommends compression and where is considered to be on the heating side?

Hmm.

I could have sworn my Potterton boiler manual tells the user to use compression fittings only.
On re-reading the manual, it does say this but its for connection only (obviously).
My Bad.

I thought it an odd requirement and had assumed it was to mitigate bore restriction from poorly soldered joints......
Likewise, i am aware that some boiler manufacturers ( again, iirc) ask for copper within a certain radius of the boiler.

 

[Exedon]

As a business we work in several different areas new build mostly plastic but use copper wherever it's seen including sink units and obviously for gas,
We do fitting out work on shops pubs restaurants which often involve plastic aluminium cored plastic (tectite metal) and copper in plant rooms and for aesthetic reasons.
Also work on quite a number of old properties many of which are listed.
On all of them we do very little soldering work virtually all press fittings.
Many customers really like the idea of no hot work.

 

[ianmcd]

I could have sworn my Potterton boiler manual tells the user to use compression fittings only.
On re-reading the manual, it does say this but its for connection only (obviously).
My Bad.

The reason for this is for maintainance purposes, when changing some components it is necessary to disconnect the pipework below the boiler, also in some cases the outlet from the boiler connection is plastic and soldering the final connection will damage it, the reason for minimum lengths of copper connected to the boiler is the plastic pipe cant always hold up in the event of the boiler over heating

 

[HERTS P&D]

On all of them we do very little soldering work virtually all press fittings.
Many customers really like the idea of no hot work.

I bet they don't like the price of the press fittings.

Andy

 

[BlueLoo]

I bet they don't like the price of the press fittings.

Andy

After the war, labour was cheap and materials expensive. In many areas of construction and engineering, design was tuned to suit. This is why you have the original Austin mini.
Same thing applies to plumbing.
Copper elbows are cheap to make but they require skilled labour and time to construct.

But the world has changed. Labour is expensive and materials are now cheap.

Modern push/compression fit systems have a higher relative component cost but assembly time is drastically reduced, as is the skill required to build them and, as noted above, the risks of construction and usage are reduced. No gas or flame required. No toxic fluxes or solders needed and a much more repeatable and consistent construction is guaranteed with no over or under soldering possible.

Also, non soldered systems are demountable to a small extent, making maintenance much easier.

From a systems perspective, its a no-brainer.

 

[ianmcd]

From a systems perspective, its a no-brainer.

Except like most pros we see so many failed pushfit joints, a properly soldered joint will never leak, DIT pushfit and even some so called pros using pushfit have a very high failure rate, have probably heard every excuse from Manus reps about why their fittings failed, always the installer, never admit their products are sub standard

 

[BlueLoo]

Except like most pros we see so many failed pushfit joints, a properly soldered joint will never leak, DIT pushfit and even some so called pros using pushfit have a very high failure rate, have probably heard every excuse from Manus reps about why their fittings failed, always the installer, never admit their products are sub standard

Skill and intelligence are two different things. Yes, non-soldered systems require less skill to assemble but they still require intelligence,

I was watching a video today from the "diary of a jobbing plumber".
Nice chap.

Repaired a customers leaking buried pipework with a press fit fitting.

Looks good but because the piping is buried, the tee being in the middle of a long run and the expansion having no where to go, the tee fitting becomes a locking point for the header run.

In service, that header run is going to put massive strain on the press fit seals and likely, you will get it leaking in the future as the seals fail.
Not a design fault. An installation fault.

As with any system, follow the OEM and you will likely be fine.

 

[Gasguru]

When you rock up at a customers house (with plastic pipe ****e) and the water's lapping over the threshold it's always comforting to know you've got copper pipework at home.
The last time I sorted out a failed fitting the neighbours had also called out a plumber...they assumed they had a leak but the water had run through the party wall