Plumbing piping and fittings

[claudia]

Speedfit have just brought out there new layflat pipe so its even more flexible and easier to use.

[Guest]

Not being impressed with plastic fittings, but impressed with plastic pipe, I now use the latter but with brass compression fittings (insert required.)

[Biggles]

I used Speedfit throughout and I used the rubber ring inserts. Country to what another said I've had no problems with the ringed inserts. I think they provide a better design.

 

I used 15 for hot and cold, 22 for the CH flow and return, and 22 for the run from the water tank to the pump.

 

I used copper for the gas of course. (both times)

[churchward]

Failure wise there nothing between the two systems.

 

The only thing that sways we towards John Guest(the people who make speed fit) rather than HEP20 is that you don't require a tool to remove the fitting which in tight corners is a bonus.

Yes I think that does it for me too. Most of the existing fittings on our boat our Hepworth (the previous screw fit version) but where I have had to amend or add something (eg when I put a new bathroom sink/taps and kitchen taps in) I used speedfit for replacement joints I don't like the idea of needing a tool. It's often awkward enough and in a confined space enough without the complication of a special tool.

 

I would echo comments above about getting a proper cutting tool for the pipe runs. getting a good square and clean edge makes for a much better joint that will be leak free.

[jonathanA]

the variations of types of fitting/pipes are all too complicated for me. I just buy whatever happens to be cheapest and it all seems to play happily together. I'll use the hep20/acorn if they exist but echo the previous comments - don't like plastic fittings that need tools to remove.

 

It seems nearly everybody uses plastic on boats so there must be a reason for that !

 

The only downside to plastic is it never looks as neat as a nice copper run, so if its on show you will need to box it in or fit clips about every 6 inches (i exaggerate but you get the point)

[David Schweizer]

I am intrigued by all the negative comments about Hep20 fittings on the basis that they require a tool to remove the fitting. How many times do you need to completely remove a fitting? I think I have only removed a couple in fifteen years.

 

Stirictly speaking, it is incorrect to state that they cannot be removed as it is only the gripper ring (and sometimes the rubber ring depending upon the type) which cannot be removed easily, but it can be done with some application, although the gripper ring is destroyed in the process. The fittings themselves can be unscrewed easily, pulled apart and removed to enable a different fitting to be added, for example a T joint where there was an elbow. But you do need compatible types which could be a problem - hence my stock of spares - just in case!

Edited July 13, 2012 by David Schweizer

[blackrose]

What water temperature can grey 22mm Hep cope with?

 

I'm plumbing my stove's backboiler into the CH system which is 22mm Hep. I'll be coming off the backboiler in 22mm copper for about 1.8m before Ting into the flow & return. The stove's flue gasses reach around 250 deg C, but I've no idea what temperature the backboiler water is?

[David Schweizer]

What water temperature can grey 22mm Hep cope with?

 

I'm plumbing my stove's backboiler into the CH system which is 22mm Hep. I'll be coming off the backboiler in 22mm copper for about 1.8m before Ting into the flow & return. The stove's flue gasses reach around 250 deg C, but I've no idea what temperature the backboiler water is?

The maximum water temperature will be 100degrees celcius, otherwise it would be steam, but the boiler casting will be much hotter. The Hep20 technical handbook states that when connecting to soild fuel boilers the first metre of piping should be copper. More info here (page 45) :- http://www.jhplumb.com/system/brand_attachments/1033/original/Hep20_Technical_handbook.pdf?1279698363

 

The water temperature produced by the boiler in our boat is about 85degrees celcius, the first couple of feet are copper and then 22mm Hep20 piping which handles that temperature with no difficulty.

Edited July 15, 2012 by David Schweizer

[blackrose]

The maximum water temperature will be 100degrees celcius, otherwise it would be steam, but the boiler casting will be much hotter. The Hep20 technical handbook states that when connecting to soild fuel boilers the first metre of piping should be copper. More info here (page 45) :- http://www.jhplumb.com/system/brand_attachments/1033/original/Hep20_Technical_handbook.pdf?1279698363

 

The water temperature produced by the boiler in our boat is about 85degrees celcius, the first couple of feet are copper and then 22mm Hep20 piping which handles that temperature with no difficulty.

 

Thanks David.

 

Mike

[churchward]

The maximum water temperature will be 100degrees celcius, otherwise it would be steam, but the boiler casting will be much hotter. The Hep20 technical handbook states that when connecting to soild fuel boilers the first metre of piping should be copper. More info here (page 45) :- http://www.jhplumb.com/system/brand_attachments/1033/original/Hep20_Technical_handbook.pdf?1279698363

 

The water temperature produced by the boiler in our boat is about 85degrees celcius, the first couple of feet are copper and then 22mm Hep20 piping which handles that temperature with no difficulty.

I agree about the first metre or so of pipe should be copper out and return. If not for the water temp then for the transfer of heat through the fittings. I also agree the temp of the water is likely to be well below 100 deg.

 

However, please excuse the pedentry but I don't seem to be able to stop myself!! 100 degrees is not the maximum temp water can get without boiling. That is only true at atmospheric pressure at sea level(and so Dependant on altitude,higher lowers the boiling point). A pressurized system can get water to higher temps. Cars have pressurized system to make sure the water doesn't boil or gas as it were at its operating temp. In theory you could heat water to any temp you like as long as one can keep upping the pressure of the vessel it is in although I recall that there is a point where the liquid reaches a critical state around 350 or 400 deg and about 200 bar pressure. Beyond the critical point water can't stay liquid as I recall. Mind you not very likely in a radiator system huh?

Edited July 15, 2012 by churchward