Plumbing questions

[karltimber]

Hi,

I have a few q's as part of the plumbing/heating part of a new ext.
I have a few questions before I start and hopefully ye will have some good sugestions and advice.

I propose to have 3/4" copper coming out of the boiler in the corner of the utility room and convert to qualpex. One set (flow & return) will go straight to the emmersion tank and the other set going to the rads.
Point A is where all the house connections are made to d/s and upstairs.

Q - I have never worked with soldered copper so am using qualpex with compression fittings --is there a difference b/t qualpex and qualpex barrier pipe ? and should I insulate them under concrete.

Q - Will I use 3/4" or 1/2" -to the rads at a point 6m & 4m away from the boiler?

Q - Submerged gas pipe.(I will not be making connections [broken link removed] ) --what size of insulated copper do I need to run (without joints) for 1. a gas cooker 2. a gas waterford stanley type stove at D and 3. from the meter box to the boiler (this will be an outside line -submerged).

Q - Can I use qualpex for to continue the mains supply or does that need to be 1/2 or 3/4" hydardar (spelling !!!) ?

Thanks in advance for your comments.
K.

 

[Carpenter]

I won't answer all your queries , however I can confirm the following:

1. Qualpex barrier pipe should be used on any pipework for central heating systems, i.e. any pipework on the primary circuit and feeding any rads. This pipe has a special barrier to prevent oxygen diffusion. Non-barrier pipe can be used in all other situations (except gas- must be copper or steel).

2. Qaulpex non-barrier can be used for your mains supply- Hydrodare is only used underground or in situations where it could be prone to mechanical damage.

3. Insulate all pipework under concrete using Tubolit or Cozytube pipe insulation- whether plastic or copper pipe is used.

4. If using compression fittings be sure to use the recommended insert (black plastic) with qualpex pipe ends.

5. Sizing of pipework to rads is dependant on layout and configuration of the boiler and rads. As a general rule rads furthest from the boiler are piped in the smaller pipe size, rads dcloser to the boiler are run in the larger pipe size. If using a manifold for flow and return (neat and easy- but may not suit an ex. installation) all flow and returns are in 1/2" as each rad has a dedicated flow and return port on the manifold.

 

[z102]

I'm no plumber but learnt the following: A pipe leaving a boiler should be made of copper for the first meter. See the latest "Construct Ireland " magazine, page 11-17, the article is titled "dead heat".
I can imagine that this is the rule with the bog standard boiler, I connected mine with barrier qualpex straight from the boiler and it was comissioned. But I use a low temperature producing combi condensing boiler for the UFH and the barrier pipe (Qualpex) is certified to take that pressure/temperature.The domestic water pipe is made as well from the same material, no problem so far.
Gas pipe: If you're planning to use LPG then the gas pipe should NOT be made from copper. But I can't tell you the technical reasons for that, I simply don't know them. But it states so in the technical guidance booklet from the various LPG supliers.Though with standard methane gas (Board Gais's product) it would be o.k..

 

[karltimber]

1. Qualpex barrier pipe should be used on any pipework for central heating systems, i.e. any pipework on the primary circuit and feeding any rads. This pipe has a special barrier to prevent oxygen diffusion. Non-barrier pipe can be used in all other situations (except gas- must be copper or steel).

I didn't know there was a different type of say 3/4" or 1/2" qualpex.
Thought it was all standard. So If I go down to my local builders providers and get x lenghts of qualpex - am I being given the non-barrier type.
How do I distinguish between the two.

thx

 

[Carpenter]

If you look at the cut end of the pipe you will see a black ring or core through the cross section. The barrier is effectively sandwiched between two layers of the PVC. In addition barrier pipe will be labelled at intervals along its length. As Heinbloed suggests the first metre or so of pipework to and from the boiler should be in copper- I neglected to mention that. Also I would make all connections to the storage cylinder in copper as well.