I need to lay about 25m of water pipe at my new mooring. Would I be better off with 20mm blue MDPE water pipe or blue food grade hosepipe? Most of it will be buried but not all of it and I read that blue MDPE isn't UV resistant.

 

The mooring floods so I was leaning towards hosepipe as it can be a single length which goes up vertically at each end so no chance of river water entering through any joints.

Blue MDPE comes in lengths longer than 25m so no need for joints. I would use the proper stuff.

Black  MDPE is uv protected so probably better than blue though I suppose you will lag it so may not matter!

For what it's worth. Several decades ago, the boaters at my current mooring installed blue MDPE under the jetty to standpipes serving four boats each and another run to a club house building.. This is still going strong. Not in direct sunlight, but getting some through the holes in the decking. Later on, CaRT adopted the installation and replaced the standpipes with their now standard stainless steel ones. We don't get flooding here though, but there would be joints at each standpipe regardless of the pipe/hose used.

1 hour ago, GUMPY said:

Blue MDPE comes in lengths longer than 25m so no need for joints. I would use the proper stuff.

 

It wasn't about the length, just that unlike flexible hose I would probably need to make joints to route it.

59 minutes ago, Phoenix_V said:

Black  MDPE is uv protected so probably better than blue though I suppose you will lag it so may not matter!

 

I thought black MDPE was for industrial and agricultural use and wasn't the right grade for potable water?

 

No I wasn't going to lag it. There's no point unless there's a heat source.

Edited October 27, 20241 yr by blackrose

I don't have access to mains water but if I did I would be very tempted to use thin bore pipe like 8mm or something.

 

It seems to me if you have a water tank and a pump rather than a direct connection (unwise on a Boat) then there is no particular reason to have a high volume supply. You could just run it constantly through a thin pipe. The times when you are not using water aboard would refill the tank. It could be calculated and keeping water moving seems sensible in some ways. 

 

It might work. 

 

 

Solenoid valve on the end of the pipe and a float switch arrangement in a small header tank plumbed and sealed to the main tank. 

17 minutes ago, blackrose said:

 

It wasn't about the length, just that unlike flexible hose I would probably need to make joints to route it.

 

I thought black MDPE was for industrial and agricultural use and wasn't the right grade for potable water?

 

No I wasn't going to lag it. There's no point unless there's a heat source.

 

I think (and it is think) that the black stuff is just like the blue stuff and its only colour coding regulations that say its not suitable for potable water, just like yellow is for gas etc etc.

 

 

If you are thinking of a direct connection to onboard (I doubt it) then its a seriously dodgy plan. I know someone who half sunk their Boat doing that and someone else who had a foot of water over the floor when they went away for a few days. 

1 minute ago, magnetman said:

...rather than a direct connection (unwise on a Boat) then there is no particular reason to have a high volume supply. You could just run it constantly through a thin pipe. 

 

I'm confused, you seem to be contradicting yourself? 

 

Anyway I don't want or need a constant supply and as you initially say, it's unwise on a boat.

1 minute ago, dmr said:

 

I think (and it is think) that the black stuff is just like the blue stuff and its only colour coding regulations that say its not suitable for potable water, just like yellow is for gas etc etc.

 

Ah ok I see, thanks. If I use MDPE I think I'll stick to blue though as others have said it doesn't suffer from UV damage too much.

Just now, blackrose said:

 

I'm confused, you seem to be contradicting yourself? 

 

Anyway I don't want or need a constant supply and as you initially say, it's unwise on a boat.

No I was talking about a way to automatically fill the tank rather than putting mains pressure straight into the Boat. 

 

I suppose it is similar in a way and could cause the same outcome but a failure of internal pipework will empty the tank anyway and it would be filling so slowly from an 8mm pipe it would take ages to be a problem. On the other hand if you have a direct mains connection (yes people do this!) it can sink the Boat very quickly. 

 

 

5 minutes ago, magnetman said:

If you are thinking of a direct connection to onboard (I doubt it) then its a seriously dodgy plan. I know someone who half sunk their Boat doing that and someone else who had a foot of water over the floor when they went away for a few days. 

 

Yes exactly, but a moment ago you seemed to be proposing that though a thin bore pipe? Perhaps I misunderstood.

Just now, magnetman said:

No I was talking about a way to automatically fill the tank rather than putting mains pressure straight into the Boat. 

 

Ok I see. No I don't need an automatic filling system. And for clarity I wasn't thinking of a direct connection to the boat  I'm not sure where that came from?

Edited October 27, 20241 yr by blackrose

Just now, blackrose said:

 

Yes exactly, but a moment ago you seemed to be proposing that though a thin bore pipe? Perhaps I misunderstood.

 

By direct I mean mains water pressure straight to the taps. No pump. 

My post above explains what I meant. 

2 minutes ago, blackrose said:

 

Yes exactly, but a moment ago you seemed to be proposing that though a thin bore pipe? Perhaps I misunderstood.

 

Ok I see. No I don't need an automatic filling system. And for clarity I wasn't thinking of a direct connection to the boat  I'm not sure where that came from?

Why do you need 20mm bore pipe to fill the water tank when the Boat is always moored there? 

 

 

2 minutes ago, magnetman said:

Why do you need 20mm bore pipe to fill the water tank when the Boat is always moored there? 

 

I don't.

My question was about the type of pipe to use rather than the diameter. As far as I'm aware and I could be wrong, the smallest diameter easily available. MDPE pipe is 20mm

2 hours ago, blackrose said:

I need to lay about 25m of water pipe at my new mooring. Would I be better off with 20mm blue MDPE water pipe or blue food grade hosepipe? Most of it will be buried but not all of it and I read that blue MDPE isn't UV resistant.

 

The mooring floods so I was leaning towards hosepipe as it can be a single length which goes up vertically at each end so no chance of river water entering through any joints.

 

 

Would you like me to send you a copy if the Water Regulations covering 'installation to provide potable water to boats ?'

I seem to recall reading somewhere that normal hosepipe is actually porous. 

52 minutes ago, Alan de Enfield said:

 

 

Would you like me to send you a copy if the Water Regulations covering 'installation to provide potable water to boats ?'

 

Not really, no thanks, but if you could just summarise the relevant bits that would be great.

11 minutes ago, magnetman said:

I seem to recall reading somewhere that normal hosepipe is actually porous. 

 

Perhaps you're thinking of porous soaker hose used in agriculture and gardening for irrigation?

 

Anyway I've never seen any signs of water around the ordinary pvc hose used to connect my water pump. It's always full of water so it can't be very porous.

Edited October 27, 20241 yr by blackrose

17 minutes ago, blackrose said:

 

Not really, no thanks, but if you could just summarise the relevant bits that would be great.

 

Perhaps you're thinking of porous soaker hose used in agriculture and gardening for irrigation?

 

Anyway I've never seen any signs of water around the ordinary pvc hose used to connect my water pump. It's always full of water so it can't be very porous.

As I remember it the hose itself can absorb things from outside. 

I did not mean irrigation soaker hose. 

Use blue MDPE, it's not expensive. It's designed to be buried. Any areas above ground should be lagged so UV is not an issue.

 

Garden Hose Degradation

As garden hoses age, they can develop porosity due to various factors. Here are some key points:

• Material degradation: Over time, the rubber or PVC material of the hose can break down, leading to microscopic cracks and holes. This allows water to seep through the hose, making it porous.
• UV exposure: Prolonged exposure to direct sunlight can cause the hose’s material to degrade, increasing its porosity.
• Chemical reactions: The hose’s material can react with chemicals in the water, such as chlorine or minerals, leading to degradation and porosity.
• Physical stress: Repeated bending, twisting, or kinking of the hose can cause micro-cracks, making it more prone to porosity.

 

(AI generated search result)

The blue mdpe going to our mooring has been exposed to sunlight for at least twenty years where it rises to the tap. No sign of degradation at all.

Echo what jonesthenuke says  blue mdpe from builders merchants or even screwfix is pretty cheap.  It's the stop taps that are eye wateringly expensive (IMO). My experience of even good quality hose pipe is its doesnt weather well and I can't see it coping with freezing well, whereas mdpe will usually cope with freezing and may occasionally blow a fitting off. If you are worried about uv then just sleeve the blue with some cheap 1 1/4 waste pipe or whatever you can find, where its not buried.

 

Just to add that one issue with none buried water pipe is that when exposed to summer sun the water can get hot enough for legionares or other nasties to grow, so bear that in mind and draw some water off if it's been stood for a while in the pipe.

Edited October 27, 20241 yr by jonathanA
Eta bit

What is this pipe connected to at the supply end? I suspect that to be fully legal your pipework should comply with the water supply regulations, and that will mean using mdpe pipe, and not hosepipe.

4 hours ago, blackrose said:

The mooring floods so I was leaning towards hosepipe

 

Is hosepipe ok for the 6 or 8 bar pressures that mains pressure sometimes climbs to at times of low demand? 

 

 

23 minutes ago, David Mack said:

What is this pipe connected to at the supply end? I suspect that to be fully legal your pipework should comply with the water supply regulations, and that will mean using mdpe pipe, and not hosepipe.

Yea that would be a nightmare, for starters the pipe would need to be buried at no less than 750mm depth and be sterilised before connection (would need certifying, chucking a bit of Milton down wouldn't cut it ... )

What about thin bore metal tubing ? 

 

 

Arrange for a continuous flow. If the Boat is lived on then the water consumption would probably be fairly predictable so one could just have the tank constantly fed. 

 

Maybe I am overthinking it but routing would be easier with thinner stuff. Flow resistance would be interesting. 

 

 

For example if one were to connect an 8mm pipe to mains supply and route ut for 250m would water come out the end or would it never get there. I think it would get there but I never tried it. 

 

Just because it would be a really slow flow isn't that relevant because the demand on the Boat is not for mains water it is for tank water delivered by a pump.