Video

Thank you for the feed back. Sorry for not answers right away. Very busy with exams and assessments. I would say yes, if this is a completely new install and there is no pipework around the home. It is still good to install it as the design goes, even if you have 15mm coming in. It will still help with all the outlets and an sure you have no problems in the future. I would also see about increasing the incoming main at the same time. But if this is already all installed then I would say leave it as is until you are upgrading the home and fix it all then. Hope this answers your question.

Hi that’s great thank you for the reply! How does mains pressure, flow rate and pipe length between sections come into this? Is there an assumptions made for these calculations? Thanks again.

Here is the link to get one but I will warn you now they are not cheap to buy... knowledge.bsigroup.com/products/specifications-for-installations-inside-buildings-conveying-water-for-human-consumption-pipe-sizing-simplified-method?version=standard Hope this helps

Thank you for your feed back, much appreciated.

Thank you for the feed back. Sorry for not answers right away. Very busy with exams and assessments. With this going into 950kW you are now on commercial gas installations. It is almost the same way of sizing everything. I have add a link below that may help you. Hope this project goes well for you. chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/www.radmidlands.co.uk/Downloads/PIPE_SIZING_PART_2.pdf

Thank you for your feed back, much appreciated

Thanks and welcome

What is it you would like to know about the onsite part of the course?

@@mglplumbingtraining4067 basically what is required from the onsite assessor, guild guidelines are very vague and confusing

That is a very good question, it's all about the outlets (taps , showers, WC's, sizes and how many of them) some have 15mm connections, others 22mm. They also have different requirements, some modern systems need 28mm pipework at the start of the run to work correctly. This is why we do the maths, this is the easier one to use, does not take long to do and check what a system needs. Taking your time and getting it right makes the different between a cowboy, a good plumber and a great one in my book.😋

I'm in assessments hell at the minute, but I am working on more phase 1 cold water videos. Just got to make time to record. Thank you for your support 👍

I'm in assessments hell at the minute, but I am working on more phase 1 cold water videos. Just got to make time to record. Thank you for your support 👍

Thank you for your support and question. Well, 1 LU is equal to 0.1 Litres per second (l/s) or (0.1 x 60) 6 Litres per minute (l/m), so if the whole installation in this video is 10 LU that would equal 1 l/s or 60 l/m. This is the best way of converting them. As the chart on page 13 is very confusing but from what I have worked out is, you get a ruler and use column 1 first using the l/s you have worked. then when you reach the bold line you go down and you can get the LU you need. But if you use my conversion you do get the same answer as the chart. Just reverse it. Say you worked out the bathroom needs 36 l/m divide by 60 seconds to get 0.6l/s and that is equal too 6LU. The Institute of Plumbing Plumbing Engineering Service Design Guide was written in 2002 and is based on the old British Standard of BS 6700. This is now been replaced by BS EN 806: 2006. Yes, we do still BS 6700 for design and if you do read it at the start it does say as my dwelling are on mains water pressure 15mm pipe will do. I have found this incorrect on a number of faulty systems I have had to fix and Combi's are just not working to the requirements of the customers with 15mm all around. For me I always found the BS 6700 very hard for people to learn how to use and once the BS EN 806 come out, it just made it so much easier to do. I have tested both ways and I found BS EN 806 to be more accurate and came out with the same type of answer every time. As BS 6700, it seem to be more of how you follow the line and read the results. Everyone comes out with answer, ever to big, to small but sometimes just right. It can be very frustrating. Hope this answered your question and has helped. 😊

@@mglplumbingtraining4067 Thanks you for your response. I am working on a large commercial building with a number of showers, WCs and wash hand basins having a total LU of 126 and giving a pipe size of 35 copper. The equivalent using the IOP gives a total LU of 203 giving a pipe size of 54 copper which is a huge difference. Also, using your assumption that 1 LU is equivalent to 0.1 l/s, the 126 LU would be equivalent to 12.6 l/s with is huge for a 35 dia pipe. The graph doesn't make sense as between 15 LU and 300 LU there is very little difference in flow rate if you use the top line.

Now I know you are talking commercial. Yes, the BS EN 806 will not work for it. This is for domestic, if you read page 14, it informs you of this. I would be using BS 6700 to work out the size of pipework, which is what IOP is based on. So, 54mm for the mains in, sounds about right. As for the chart showing the Design flow rate (QD) in l/s for standard-installations in relation to the total flow rate (QT) in LU. It is just showing us how they get the LU using the requires of the domestic system design. As I didn't design this chart, your guess is as good as mine. In table 2, it tells you the requirements for all appliance's, as shown in this video. Sounds like it's going to be a fun job. good luck and enjoy 😀

@@ivanrebello3834 because the larger your total flow rate, the more diversity that can be applied to the system

Hi Julijus Buivydas, this is a great question and even got me thinking. Hope this answers your question. The max we normally work to for inside a domestic dwelling is 76mm in copper and 63mm PEX, for underground pipework to the dwelling the max is 63mm for MDPE but this is very rare, the biggest I have worked within a domestic dwelling was 35mm copper and 32mm PEX When it comes to multi-storey (Flats, apartment and hotels) or industrial this size of pipework is common and have been known to go bigger. I have worked with 110mm copper and steel in these types of installations. Yes, you could use 25mm PEX for it all but it should not be left anywhere the sun can hit it, as it will degrade it over time. It would work but you will still need to reduce it's size to make the final connections to the outlets. 15mm to Kitchen sinks, toilet and basins and 22mm to baths are the standard sizes of pipework to them. The cost would be greater but you would have the best flow ever to all outlets as long as your incoming main is larger than the pipework inside and you have good pressure.

@@mglplumbingtraining4067 yes the main question was if i can make the pipe work to every single draw off points D25 (we are talking about pex pipes) because as i heard too big pipe will reduces pressure in the house, especially in the shower and sinks. Plus if there is too big pipe in the shover, we will have to wait for a very long to get hot water, esspecialy over 15/20m distances. Planning to put in recirculating pump, but still does thos pump line should be the same D25 or it can be smaller? Likr D16 or something like that. P.s. main pipe is D32 PE. In the house is 6 sinks, 2 showers, 2 WC, a bath tub, washing machine, boiler, dishwasher. 4 persons 150m2 farest ends 14m flat distance (~20m of pipe work)

As long as the mains pipework coming in is bigger and has the pressure it will not effect the pressure you should get. When you go from small pipe to large then it will have an effect and reduce the pressure. But when you design the system correctly the pipework will go from large to smaller which will keep the pressures you require. PEX pipework is for inside use and not for under the ground, your mains coming in would more likely MDPE. If your pipework is 15 to 20 away from the heat sources, you already have a dead leg in the system, meaning the water would take to long to get hot at the outlet and would be a waste of water. It should have never been designed that way. No plumber would have fitted it like that. A secondary circulation (Bronze pump) would solve the problem of the dead leg but it would need to be design and installed correctly for it to work.

Hi, and thank you. This is for domestic use only, so only low pressure. There is no high pressure unless you complete the industrial qualification of the gas industry. Which, because of how dangerous it is, is something I would not put on here. Sorry

@@mglplumbingtraining4067 thanks you for your answer. Could you advise me the standard code for high pressure?

​@@reasmeingor1962If the pressure is greater than 6m³/hr and natural gas. You will need to follow IGEM/GM/6[10] or IGE/GM/8[11] If the pipework is great than 35mm in Industrial and commercial premises you will need IGEM/UP/2[12] Hope this answers your question.

Hi and thank you for your question, Sorry, I didn’t answer right away, I have been away and not near any of the paperwork. First off your British is out of date and we are now on BS 6700:2006+A1:2009 but I have an old copy and have found the page you are talking about. In the new Standards, this is on pages 120 and 121. A lot more pages have been added but in this case, the information is the same so all ok. The loading units used in BS6700 are different from BS EN 806 part 3 as they use different formulas to work out the sizing of the pipework. So sorry there is no formula to represent in relation to loading units and flow rates. They both work and we still use BS 6700 when we are wanting a more precise answer but is very long-winded to complete and you have to use the chart to take the loading units you have worked out for the dwelling. Then mark it onto the chart which then shows you the flow rates that you need for the next part of the equation. With BS EN 806 part 3, they have already done this and cut the formula down, this is why the title is ‘Pipe Sizing Simplified’ on the front of the document. Hope this answered your question, anything else please feel free to ask.

You are correct, there are 4 routes and the last 3 parts are the S-plan plus system for each route but the only rule City &Guilds say is, if your assessing 4 students, each should be on a different route, so 1 on A, 1 on B and so on. They get 1 go at it and if they fail, they do a different route for upto 4 tries, after that they fail and go back to the start of phase 3. Hope this helps. Anything else, feel free to ask 😌

The only other problem we are having with this at the moment is setting up the dedicated maintained area for the these assignments 😆 no more room

@@mglplumbingtraining4067 Brilliant, that clears that one up for me thank you!

Yes, this is true but there are some combi's with a 22mm connection but the main thing is if your hot water pipework works out to be greater than 15mm, you should want to think about a unvented cylinder not a combi. But if your not worried about it then you can fit a combi with a 15mm pipework and live with the pressure loss around the home. Remember this is a guide not a regulation, its the designers choice in the end.

To find out the mains pressure you will need a Mains water pressure gauge. The one I use is this www.screwfix.com/p/monument-tools-mains-water-pressure-test-gauge-11bar/82412?kpid=82412&ds_kid=92700055262507126&ds_rl=1244066&gclid=CjwKCAjwiJqWBhBdEiwAtESPaIzIFoDGvFz1LVMSzuvfwublWCskYfwt8kKMrQRmW0fyM5kLxo9tNBoCH5IQAvD_BwE&gclsrc=aw.ds You fit it to an outside tap and turn it on, the pressure will go up giving you the standing pressure, then open another tap inside and check the gauge again and this will give you the working pressure. Hope this answers your question.

Sorry I have been in assessment and feedback hell with my groups at the moment and a little snowed under but once everything calms down I have a number of video's ready to be recorded, so yes more will be on there way soon. If there is any specific areas you are after, please let me know. Thank you for your support.

Hi, Good question, and yes you are correct but after a number of times working out pipe sizing using them both I came up with the same answer, so now I just use the copper one for both. Plus I didn't want to risk being hit with a copyright showing more of the BS EN 806 part 3, so left it out. If you would like me to, I will be happy once I get time to make another one for polybutylene (PB) and (PEX) I will and I will use the same plans. Thank you for your question and your support.

Hi Eranda, Yes, I can do that. I am working on one at the moment which should cover what you are asking for. This one is covering the older BS 6700 which BS EN 806 replaced.

Your guess is as good as mine? 😆

Thank you for your support. I am working on think's at the min and there will be heating design coming.

Thanks! Will do!

Thank for your support 🙏

Thank you for your support.

Sizing hot water return pipe and pump

I will be make them soon, just got to finish the sciences first. 🙂

Glad it was helpful! Thank you for your support and good luck in the future ;)

@@mglplumbingtraining4067 do you have any videos on purge volume and installation volume so you know of you can work onit and how much to purge it would be great

Thank you for you're suggestion, it is one that is in the works a long with flue's and ventilation yes, just getting my groups running and I will be recording again very soon. Just trying to work out which part of plumbing and gas to work on first.

6.3 KW boiler

You work it out the same way you would for the cold water, what appliances are using the hot water? So if you had 1 basin, 1 kitchen sink and a bath. you would add up their loading units and that would be your combi's units. Bath is 4, plus 2 for sink and 1 for basin equals 7 loading units. You then add your combi to the cold water drawing where it should be and size from there. I am getting asked this one a lot so I am working on a video for both when you have combi's or an unvented cylinder on your cold water system. Plus adding the hot water sizing too. Hope this has helped and answered your question. Any other questions please feel free to ask.

Boiler size does not matter as much, the important bit is how many appliances it is suppling as that will be the total loading units you would use.

@@mglplumbingtraining4067 Hello, thank you for your answer. Cold water is taken out of the tank and distributed to the equipment, and finally enters the boiler. It is distributed to the equipment as hot water. I can calculate of hot water coming out of the boiler, I can calculate of cold water coming out of the tank. But I don't know the cold water calculate that enters the boiler. in short, cold water is distributed from the tank and finally enters the boiler. I calculate from the combi to the tank. By giving the combi approximately 4 loading units. Is that true?

@@mglplumbingtraining4067 And how much loading units for per radiator?

Hi, and thanks for your support. I am well and getting ready for my new students to start soon ;) Hope you are well too. Thank you for the very good question. No you are not over thinking, you are thinking in the correct way. ;) To answer your question, yes true, it would be 4LU, and yes it is 2LU on the cold and 2LU on the hot but we do not add them together as they are 2 different pipe runs and completely different. But if we are using a Combination boiler, I would have to add all the outlets of hot water together (bath 4LU, basin 1LU and sink 2LU) equaling 7LU and show the boiler on the drawing for the cold water. Yes, then all this would change the size of the incoming main and the pipework going to the boiler. I would then have to draw another plan for the hot pipe runs and size them too but this time from the boiler to the outlets. Again thank you for your great question and I hope my answer help.

@@mglplumbingtraining4067 Hi, thanks for replying ! Crystal clear ! You’ve explained it well ! Hot and cold LU’s are added before going into the combination boiler. But hot water is sized separately when leaving the combi-boiler to serve outlets ! Thanks ! Amazing channel !! Keep up the hard work ! Hopefully it will pay off !! Thanks again !! And best of luck with your new students ! Am sure they’ll learn a lot from you !! 👌👌👌

Thank you for your support

Sorry was on holiday, Thank you very much.

Hi Luke, Sorry, it has taken so long to answer. (Holiday) Thank you for your support and good luck in your new career in teaching. It is a fun one and can be very rewarding but it is hard work at times. This is a very new qualification and is still being added to by City & Guilds as it has just been updated this month. The main thing is only teach what is need for that phase you are on. Do not over teach it just stick to the qualification handbook. (Linked below). This is the trick, just follow that and do not let anyone tell you it's just like the old qualification and use the old slides. It will not work. Also, make sure your students have the City & Guilds Book 1 and 2, and Water Regulations. It will make your life so much easier. www.cityandguilds.com/-/media/productdocuments/building_services_industry/plumbing/9189/on-programme/9189-04-07_l3_diploma_in_plumbing_and_domestic_heating_handbook_v2-1-pdf.ashx I am working on Phase 1 plumbing science at the moment. I was thinking of completing some videos on the areas you are asking about but was unsure if anyone would want to watch them. Once I get the flow going (forgive the pun;)) I will work on some of them for you. If you have any more questions feel free to ask. Again thank you for your support.

Thank you for your feedback, at this time I am working on the science of plumbing part of this course but I have made a note of this and will get to it for you as soon as I can.

More are coming, I just have to finish teaching my groups. I have just finished an updated gas pipe sizing presentation and will be recording it soon. Thank you for your support.

I am just fighting with the new 8202 level 3 course at the moment, I have to finish the whole group I am teaching soon. All go to plan I will have more time to make more videos. Thank you for your support.