HOW TO SIZE A GAS PIPE, A tutorial for trainee gas engineers on how to size a gas pipe to bs 6891.

[@woolf147]

One of the best teachers explaining how to learn to size instillation . I have raised a complaint in LCL as they don’t supply sheets (form to fill all the details) it’s confusing and I noticed many trainees don’t understand at all. If sheet was there it would have opened they eyes faster:))). Thank you Derek I will share your videos with my group.

[@IsleofWightBushcraft]

Very helpful, I’ve been in the industry for over 35 years, and this is the best paced explanation of Gas pipe sizing I’ve heard so far. Top job.

[@Carl-re6zb]

Derek sir you are an absolute gent. I was recently trying to remember how to estimate pipe sizing and always struggled with the bit about adding the pipe sections... From this tutorial it suddenly makes sense... 20 years after passing my first ACS...🤪 Thank you once again ..

[@seb1963]

Best teacher ever!!! I’m renewing my ACS soon as it’s expiring. I did my initial assessment 5 years ago, but didn’t work in gas at all. I decided I need to renew it and I’m so thankful for your videos mate. I feel like I’m learning more now thank on my initial 😂 top man!

[@diasporaactionsfornigeriap6440]

Well planned and delivered. The clarity is amazing. Tank you for this video on piping calculations. Thanks.

[@mohammednadeem7274]

Great video Derek, really well explained and easy to follow when doing pipe sizing, getting the correct pipe sizes is really important as it makes a big difference with the pressure drop. Doing this in class at tomkat it does pull your hair out but once you get your head down to it and get to understand the process it makes it enjoyable in sizing the pipes for the appliances. Excellent video Derek..👍👍😁😀

[@pooka9052]

Long winded yes, but very useful. Of course you gave the worst case scenario but it included most typical examples. Very clear and great help, thanks.

[@lmcm7311]

The Books are clearly only a guide Derek fills in the__Gaps__ & helps you to understand everything clearly & easily what a massive help these videos are to us Trainees 👍🏻

[@mj0n4id36]

This video is awesome! Really informative. Really helpful. Every step explained clearly. There is no chance I can go wrong if I carefully follow the steps you have outlined. (I should have watched this before attempting the homework 🤣) Thanks Derek. Top video. 👍🏻 Asian Jon. Training.

[@timmyshah6450]

Pipe sizing made easy by Derek Brilliant video 👍👍

[@jon-paulward4580]

Jon-Paul Ward. Thanks for another informative video Derek. Very easy to follow and understand.👍

[@brenndonherbert4583]

Great video as alway. Have my ACS in 3 weeks and this was a great refresher.

[@tomkatgastraining]

Good luck 👍🏻

[@dalesmith2510]

Great Tom , it was very helpful for me training 👍. Well done 👏

[@hooriabilal5640]

Great Video Derek. Very well explained all the requirements and calculations. Bilal M (billy) Tomkat trainee

[@deniswatfordsmart1049]

Cleared a few doubts I was having thanks

[@frankdunham6051]

Brilliant explanation, I watched this one while doing a bit of revision and it helped massively. Top bloke :)

[@jonmay289]

Another great video thanks, only thing I would mention is g4 u6 meters are unlikely to pass 70kw of gas , but great tutorial 👍

[@ionsprinceana5048]

Great video sir, love all your tutorials, you are helping so much , thank you !

[@ivangoodall1]

Thanks again Derek, another great informative video.

[@ab18i]

As with all your other videos- very comprehensive. nice one thank you.

[@ninobrown76]

Thanks Mr D for this well illustrated video.

[@dannymatona3506]

Excellent vid. Your vids help me out daily.

[@davidproctor6359]

mastered pipe sizing yet again, thanks.

[@hamzaparvais3948]

Thank u so much am grateful for ur time and effort beautifully explained

[@stevebryans9270]

Derek is it correct to include the tee at B in the first calculation Is the tee at B to be considered when doing B-D

[@haydernagey5881]

Excellent tutorial many thanks Derek, HAPPY CHRISTMAS & NEW YEAR.

[@tomkatgastraining]

Happy Xmas and new year to you too 👍🏻

[@mohammednazir8307]

Brilliant video Derek 😊

[@olivierjunior7048]

You are the best Derek

[@lukebrown9837]

Absolutely amazing explanation! Thanks so much

[@richardhodgson7443]

Great video Derek thanks again for your training videos

[@Liam07382]

Proper handy video, understand it perfectly now👍🏻

[@willlomas2725]

Great video Derek.....Thanks fella.

[@garryafurze]

Great Video! Doing my gas right now and this video is Great! 👍

[@garryafurze]

Do you have a video on Reg’s? 🤞

[@piotrmarchwacki3414]

Perfect Derek. Great explanation. Thank you very much 😀👍

[@jasongittoes7299]

A lot easier to follow many thanks derek

[@gulammustafa8562]

Wow very well explained very helpful thank you very much

[@Zinadene69]

Hi Derek, I love your video’s and like many viewers I have found them so very interesting and useful to understand about all aspects of gas safety. This is where I am a little nervous, because I am going to question the way you are interpreting the equivalent length when it comes to the Tee fittings, specifically between the meter and the Boiler. The way I am reading it, is you only need account for a Tee Fitting, when the flow is either ‘entering’ or ‘exiting’ a Tee, not when the gas flow is going straight through it. In your diagram, where the Tee is located at point B, the Gas Flow is not entering or exiting a Tee branch, its going straight through it, so does that not suggest that when accounting for gas flowing to the boiler, the Tee connector at B should not be accounted for? Of course you would account for the Tee fitting at point B, when working out the Pipe size from B to D, because in that case the gas is exiting the branch, but if the gas is not flowing in or out of a Tee branch, isn’t that like having a straight piece of pipe from the Meter to the boiler with six 90 degree elbows (1 elbow from A to B and 5 elbows from B to C). If you could please clarify this point I would be much obliged. Regards Steve

[@tomkatgastraining]

Like I say to everyone who brings this up I always count the tee on the first calculation because that would be the biggest size of pipe. Then it is not counted again because if you think about it logically the other 2 pipes could be smaller so less equivalent length. Pipe sizing isn’t an exact science because they don’t give you the figures for every calculation for the m3. So this video is to show the process and so guys understand the process if you don’t want to count the tee first then don’t do it the way you want to as the results will be the same.

[@Михаиллеви]

Your channel is a god send but on this point I was taught as per the OP on entering and exiting Tees. My LCL book issue 5.0 page D6 shows clearly what the branch is. It has an asterix note below which deals with the largest connection issue. The actual rules in BS6891 have a Table A.5 confirming this and the asterix comment.

[@thealifamily8090]

This video really helped with my revision. Legend. Mo😁

[@nouraldeenjbawi7231]

Thanks for the video Can you talk about the burner pressure (method statement )

[@timeyre9985]

this Man is a god damn genius. I had almost given up the will to live until I saw this!!! Next gas course I will find a hotel to stop in Ashton under lyne

[@hectorheath9742]

Hah! This is a really good comprehensive video and I'm only here in passing. But I'm also from Ashton and I know what the hotels USED to be like there! Choose carefully!

[@hdhanji8006]

Good stuff Derek, making pipe sizing look easy as pie :)

[@Jboy777-t1z]

Derek, I've seen one video from another training company showing that you add the exiting tee to the route that it exits onto, instead of doing it with the route that approaches the tee? I trust you more than them but just wanted to double check. thank you for all your helpful videos !

[@tomkatgastraining]

@@Jboy777-t1z the biggest size of the tee will be the one that approaches so that’s why I add the tee first then you don’t add it again on the branch.

[@Jboy777-t1z]

@@tomkatgastraining thanks matey

[@Jboy777-t1z]

@@tomkatgastraining thanks matey, viva academy are training people incorrectly then it seems

[@jasongittoes7299]

Many thanks for the video very easy video to follow for a trainee like me

[@vladimirstafasani4630]

Absolutely great video love it. Well done 👍

[@lilhanahatz3641]

Well explanation, really understood

[@johnfox982]

Thanks Derek very well explained

[@marcusgreen1715]

Top lesson derek nice one

[@aaronjoyce1980]

Top vid again Derek. You make this look easy thow lol 😁 Can't wait to get back to training 👍

[@michellecassar5785]

Hi Derek, super helpful. THANK YOU!! Have you created a test one?!

[@tomkatgastraining]

Nope but do you think I need to

[@minhajsyed-r2s]

Can we use the same design methodology (including 1mbar pressure drop) for commercial gas kitchens and communal heating systems with multiple boilers?

[@aghasahib4703]

Could you please upload a video on notching joists.

[@tomkatgastraining]

That might be worth a video 👍🏻

[@osgarmz5848]

Great Vid Derek thanks, I have a question. I was fitting a bathroom at a large building that's being converted to flats. I had to get some stuff from the outside store. I noticed all the gas meters are u6 with 22mm outlets going to 28mm track pipe then to what looks like 2.5" yellow in a floor chamber, then travels under block paving about 60 m into the building reducing to 28mm trac pipe to feed Combi boilers in each flat. My question would be & I raised this with the project manager. A) Is it normal to reduce up. B) Will the length of run have a load factor on the meter size. TIA

[@tomkatgastraining]

The meter will be fine but obviously checks would need to be carried out on the appliances to check the pipe sizing and also the volume of the pipe will need to be checked that it doesn’t exceed 0.035 m3

[@roberthallas349]

Hi, if we change a 15.5 kw integrated boiler (with hot Water tank inside it) in the airing cupboard, on the first floor, with 22mm copper pipe, from the meter, a branch to the gas hob, on the ground floor, with approximately 8 metres, for a 30 kw combi boiler in the loft, could I use the 22mm pipe, or extend with 35 mm pipe into the loft? Thanks.

[@richardhall8704]

great example any chance you can guide me to where i can get the chart print offs lm just starting off to becoming a assessor and need all the help i can get ps love the videos and the way you explain everything so clearly

[@tomkatgastraining]

I made the charts but you are free to copy them from the video 👍🏻

[@richardhall8704]

Great thanks a lot

[@alaap121]

Great clip, could you also do a clip on flueing/chimney standards, would be very useful thanks again

[@tomkatgastraining]

KEEPIT STOCK coming soon 👍🏻

[@aghasahib4703]

Absolutely brilliant mate. Thanks alot

[@vickyr8360]

I have a situation, my new firepit requires 240k and it is 60’ away from meter. The current pipe line is as follows-from gas meter 1” pipe size for 50’ distance and then branch out for 1/2” size for next 10’ distance to fire pit.Does this current pipe system would be good enough for 240k btu firepit?

[@AhmedAhmed-zj4zd]

Many thanks mr Darek u helps me a lot

[@theritual923]

do you sell the paperwork blank sheets you use in this tutorial. or where can it be bought. great videos .thx

[@joco5906]

Hi Derek, can I double check the flow rate calculations with you. So a 30kw net boiler would have a flow rate of 3.094 m³ (30×1.11÷10.76). Where does a multiplication factor of 0.095 come from?

[@rivkiroyde4362]

Thanks Derek great video

[@eddiecockayne4893]

I should know this but becuase of brain fade tell me do these calcs assume that all appliances could be on full rate at the same time?

[@tomkatgastraining]

No because they say it’s unlikely

[@iprinced]

Make sure to check for installation volume after to! Sorry but the pipework you gave in metres and sizes. Are they within the 0.035 m3 (maximum installation volume) as per IGEM/UP/1B). Thank you

[@tomkatgastraining]

You are correct but this video is on pipe sizing not purging I have another video for that

[@Sumon36]

Hi Derek That’s a great video. Any chance you can share your template pleas?

[@terrygreer1783]

Hi hope your all doing well great videos, will you ever be doing any commercial videos I can’t see many people doing them.

[@tomkatgastraining]

They are in the pipeline 👍🏻

[@terrygreer1783]

Perfect thank you I look forward to watching them, have a good weekend ✌🏼🍺

[@tomkatgastraining]

@@terrygreer1783 you too 👍🏻

[@WeShowMemes537]

Hi Derek one question. Last section from A to H .should we include F to G in pressure loss

[@michaelrose5040]

Amazing thats so easy to understand

[@kpereira8910]

Thank you Sir. Brilliant stuff as always. just wondering, does reducers affect on pressure drop like other fittings or not? Thank you.

[@tomkatgastraining]

K Pereira yes it dose but not enough to worry about it’s all about the tees

[@kpereira8910]

@@tomkatgastraining Great. Thank you sir.

[@Jehannum2000]

@@kpereira8910 One-size reducers give about the same pressure loss as an elbow of the same diameter as the reducer's inlet. BS 6891 does not give equivalent lengths for reducers but the commercial pipework standard IGEM/UP/2 does.

[@msuk5957]

Thank you a lot Derek 😊

[@tommyblackman7119]

Excellent video Derek, Exactly what I did in my acs earlier this year an yes mind bending at first but once you have the hang of it it’s simple.. I agree some engineers say it’s take to much time up an wont do it.. basically they can’t do it But can you please confirm the 1mb from meter to appliance is per appliance or over all appliances running together .. as you drawings an appliances an pressure loss over4 appliances running together would be well over a 4mb drop. Saying that everything would have to be bigger pipe sized.. I’m only asking as I was told/taught that it’s over all appliances Thanks an great video 👍

[@tomkatgastraining]

Tommy Blackman the way I have shown on the video is the way the British standards says it should be done. Must admit I don’t teach it this way to my students because in real life it doesn’t work if you have all the appliances on we do a running total but the standards say there is a very small chance you will have all the appliances on running at full rate at the same time. Thanks for watching cheers

[@tommyblackman7119]

Tomkat Gas Training excellent Derek, thanks that’s sums that up Stops me stressing looking at installations an thinking everything is under sized Thanks again Derek. Great video An many people don’t commit to gas pipe sizing

[@diljin1093]

Hi Bro please make a video obout, where I get questions 35mm pipe 18 meter length and what is pressure flow rate

[@WORKISNEVEROVER8]

great video but how do you equate reducing fittings i,e tees and sockets into different pipe sizes or are the fittings chart the same flow rate no matter the tee ? eg. A-B is in 35mm teeing into B-C in 22mm and then B-D in 28mm. again great video learnt a lot

[@tomkatgastraining]

No reduction for sockets or reducers or reducing tees just elbows bends and equal tees with gas entering or exiting the branch

[@WORKISNEVEROVER8]

@@tomkatgastraining thank you

[@jordansiddall6235]

Great video cheers Derrick. Jordan

[@ronmaren4135]

10:09 you go for 28mm, is there any specific reason why for that? beside experience. Such as ''if total kw of the appliances more than 40kw'' or ''the total lenght of the pipeline is more than 20 meters'' etc?

[@petelovett1301]

Hi, a to b only has an elbow, the exiting t will be on b to d

[@tomkatgastraining]

Some trainers train it as if the gas goes straight through don’t count it but in reality would you be installing a 35mm tee or a 28mm tee so I always count the tees on the first pipe because at the end of the day it makes no difference.

[@RickyMandes]

Hi Derek planing to open a cafe and don’t have a gas in the building and called the gas supplier and before they install it they want to know annual load kWh and peak instantaneous demand kWh as well. How do I calculate I asked some British gas guys while they are on the job and they don’t have no clue 😊 can you able to help what would be the similar cafe or restaurant if you can guide many thanks

[@tomkatgastraining]

I have done a video on meter sizing so check that out

[@dafyddisrael5513]

Very good video. Where can I get a copy of the gas flow chart please? Have the viper book and second addition book and i cannot find it ??

[@tomkatgastraining]

They are in all new training manuals

[@MrRichardBenton]

Hi Derek..great video as normal but where can I download the paper charts from please..keep up the good work

[@tomkatgastraining]

I made the chart sorry

[@lostinthoughtscalminsilenc8167]

Do we have to convert to net for pipe sizing? Thank you

[@tomkatgastraining]

It is better to convert to net at the beginning to make it easier but you could use gross then convert to net

[@Jehannum2000]

The charts in BS 6891 give values in kW net, kW gross and cubic metres per hour. As long as you use the correct column, you should not need to convert. It's best to be consistent in which one you use, of course.

[@lostinthoughtscalminsilenc8167]

@@Jehannum2000 very true thanks

[@danielwilliams-pp6wl]

Good evening, a comment. IGEM/UP/2 edition 3 guidance document states that gas pipework system should be designed from the gas meter to the appliance with a max drip drop of 1mbar. It later states that the appliance must also be safety set to work in accordance with the manufacturers minimum working pressure which does not mean that you must achieve the max 1mbar pressure drop it can infact be much higher.

[@tomkatgastraining]

You should supply enough gas so that there is not more than a 1 mbr drop when installing a new appliance what you are talking about is when you are testing an old appliance and you missed the bit that says and not affect the safe operation of any other appliance.

[@saltnvinni1]

Hi TomKat Gas Training, I was wondering why a T fitting has been used for the A-B section, when the book says that 'no tee allowance is required for pipes running straight through'. Shouldn’t the Tee section be used for the branch section, B-D? Thank you.

[@tomkatgastraining]

I count the tee when you first encounter it and then don’t count it again it still works out the same and you won’t reduce the pipe after the tee it would be deduced by the tee

[@saltnvinni1]

Tomkat Gas Training thanks, would you get penalised for that during assessment?

[@tomkatgastraining]

@@saltnvinni1 it’s not this complicated and if it was you would get the same answers

[@saltnvinni1]

Tomkat Gas Training thank you for answering and your fantastic videos!

[@1Monaghan]

Excellent right in at the deep end with this. If you can do pipework sizing this big then the ACS exam should be easy.

[@micktierney6646]

I have a query, the branch of the tee at B supplies all appliances except the boiler but you appear to have used the branch exit as the boiler supply not the other appliances. Is my observation correct or am I missing something (hopefully not all my marbles)?

[@tomkatgastraining]

I have been asked this a lot in the questions. If you look at it logically your first pipe size is a to b. So I count the tee here because this would be the biggest size of the tee. I then don’t count it again as it has already been accounted for at its biggest size so worst case scenario. At the end of the day it’s up to you when you count it as pipe sizing isn’t an exact science as long as you get the correct amount of gas at the appliances.

[@micktierney6646]

@@tomkatgastraining thanks

[@cazza1295]

What determines the kw you use on your drawings? Is it always the hot water max input kw you work off ? On a combi heat only and system is it always the hot water input kw in the MI’s you’ll work off and use on your drawings

[@tomkatgastraining]

The maximum kw designated by the manufacturers so for combis the hot water kw like you said

[@cazza1295]

@@tomkatgastraining hi Tom so as an example a vaillant 418 heat only boiler is 18kw output , 18.4Kw ch input and 25.7kw hot water input, what would I size it too here for a heat only boiler ?

[@tomkatgastraining]

@@cazza1295 as I said the maximum heat input laid out by the manufacturer

[@cazza1295]

@@tomkatgastraining okay understood, so when you gas rate a boiler a vaillant for example, In service mode PO1 does that fire the boiler at hot water max rate then ?

[@tomkatgastraining]

@@cazza1295 not necessarily you will need to use the data badge to determine the maximum heat input

[@ahmaddarwiche9154]

Very good information thank you

[@enochi5219]

this helped so much

[@ant-04]

Hiya, if a result is 0.517 or 0.016 for example what is the best size pipe? When looking at mock questions on pipe sizing it asks a pipe size for said length and given gas rate but the awnser could be one or the other 28mm or 35mm for example. Would you select the 35mm to allow for future adaptations to the system or select the 28mm cause it’s cheaper for the customer and is correct for the current installation?

[@tomkatgastraining]

Why allow for future adaptations when you have no clue what would be added. 28mm for me

[@ant-04]

@Tomkat Gas Training thank you! Really appreciate you taking the time to reply.

[@ianferguson8367]

my brain burst already Derek

[@flash999able]

Is it correct to assume A-B and B-C to the Boiler, do not include a Tee. as they do not cause any resistance.... And that B-D. would have 2 tee's. 1 Entering and 1 Exiting tee. I am a Bit confused about where to include the Tee's in Each section.

[@tomkatgastraining]

The tee is counted in a to b because that tee will be at its biggest size

[@flash999able]

@@tomkatgastraining Thanks, Much Appreciated. if the pipework was all the same size from A-B and B-C and B-D would it be correct to include the two Tee's on the B-D Section.

[@tomkatgastraining]

@@flash999able if you think about it logically would you count something at the beginning or the end I always count it first but at the end of the day you can count it when you like you are designing it most of the time

[@flash999able]

@@tomkatgastraining Thanks, that makes it a bit clearer... Excellent Training and Educational videos. Keep up the Good Work.

[@adreenryan2901]

If you use sweeping bends to that appliance c 22mm pipe would be plenty.

[@masterchaz100]

can i just ask where the conversion figure 0.095 comes from and can this be used in any part of the uk or is this based on a certain calorific value? also when pipe sizing is this done in NET or GROSS?

[@tomkatgastraining]

It’s a standard across the U.K.

[@qhero4503]

Thank you its very helpful video

[@D21-n8u]

Where can I download the charts?

[@jaseydaws]

Hi Derek I have a question? - if the max flow rate in M3/h is 6.65m3/h - and it's a G4 meter - would that not exceed the max flow rate of 6m3/h or would allowance for all the appliances not being on at the same time be a factor? Thanks!

[@tomkatgastraining]

When sizing a mater you use a diversity factor not the full kw

[@jaseydaws]

@@tomkatgastraining of course!!! 80% & 60% - thanks for answering! & thanks the videos, They are quality!

[@raul835]

If you bend the pipe and don't use a 90 fitting.. how does that affect the calculation? Help pls Derek.

[@Jehannum2000]

You get about half the equivalent length of an elbow, assuming you bend the pipe properly without 'ripples'.

[@MAmanchester]

Derek, not all these sections add up to less than 1mb. That should be the case no? Each section alone should be under 1mb and added together also under 1mb. If that is the case i updated B>C to 28mm and F>G to 22mm and F>H also 22mm, this gave total loss of 0.9mb as opposed to 1.77mb for all sections in your calculations.

[@tomkatgastraining]

No you don’t add them all together I have followed the procedure laid out but the British standards. Even when sizing a gas gas meter now we don’t use the full kw of the appliances

[@MAmanchester]

@@tomkatgastraining Thanks for the reply. Doing my ACS training at the moment and this is what I have been told, strange. Thanks again.

[@tomkatgastraining]

@@MAmanchester good job the part of the exam for pipe sizing is only one appliance then 🙄

[@MAmanchester]

@@tomkatgastraining either way your video helped refresh me, not looked at it for months. Did this example fair easily. So long as I know I don’t have to add them all up it’s groovy

[@mohammadshamsparwez7332]

Hi thank you for explaining the gas pipe size calculation. I need to calculate LPG pipe size of the boiler, I have 4 nos. of boilers each consumption is 1749 KW = 54m3/hr LPG, but in the table not available flow rate to select the losses. please I need your help to calculate the LPG pipe size fro boiler,

[@tomkatgastraining]

I am not surprised it’s not in the book are you correct with your kw and m3

[@mohammadshamsparwez7332]

@@tomkatgastraining thank you for your reply. The gas consumption of boiler is correct. Which is 1749 KW. (59,71,086) BTU. I am in Qatar here LPG heat value is 1 m3 of LPG = 110,000 BTU or 32.22 KW. Operating pressure of boiler is 20-200 mbar.

[@tomkatgastraining]

@@mohammadshamsparwez7332 what is the boiler powering a city

[@mohammadshamsparwez7332]

@@tomkatgastraining boiler is used for the big military hospital for steam generation. Final uses of steam it’s not available now. My scope only to provide LPG pipe line Connection to boiler.

[@tomkatgastraining]

@@mohammadshamsparwez7332 how much lpg do you have in the storage tank

[@brendanmoran9516]

Thanks for the video. Thank you.

[@Sam-jm7tx]

Thank you, Very helpful

[@nurdinmsangi7351]

How can i get the chart you use