This one covers wrought iron pipe sizing for natural gas systems. This method is the branch length method (402.4.2) and conforms to the IFGC 2009 code book. The charts are the same in the 2012 code book, just different page numbers.
7yrs later and this is STILL extremely helpful and so very easy to understand. This is the best instructional video I've seen in YT thus far. It just sucks that I had to watch 8 before, finding this. FYI table 402.4(2) in the 2018 book.
Old video...but for all of you checking this out. On table the numbers displayed is for CF/hr not BTU's... 1100 BTU equals 1 CF/hr. You must divide the 350,000 BTU's for 1100 to find the CF/hr to use the table. He missed that step and therefore had a size or two larger pipes that he needed. Good luck!
Just a homeowner redoing my gas pipes to accommodate adding a tankless water heater and high output gas fireplace, but found this really helpful. Oversized everything to 1" and reduced right before appliances. Gas company came out to hook up at meter and said I could have just had them bump up the pressure instead. Whatever, I sleep well at night and no more rusty 40 year old gas pipe hanging from coat hanger wire under the house and which some idiot thought needed insulated with rolled newspapers.
Thank you so much for this. I had suspected that the builder had drastically undersized the gas piping in my new home and this proves it. There is no way that a system with a 6-8" WC regulator using 1/2" piping with 1/2" drops is suitable for an 85K BTU furnace, water heater, stove, and gas dryer. It's also worth noting that the 2018 edition of NFPA 54 also has foot equivalents for fittings like 90's 45's and T's.
I would stay in the 70' column/row for all pipe size calculation. End up with the same the same result. The way I was taught. Using your video to teach a few apprentices. Thank you for posting this video.
@@tracker1ify u measure main run from the meter to the furthest appliance. Then u look in your book and you stay in that column forever. And you go off of those btus to select pipesizes
Great the 2 lb system is popular in our area, We will be watching for your next video to come out this winter. Thanks Again Your Expertise Makes it Easy for Us Dummies
My teacher spent roughly 6 minutes trying to explain this process to a room full of 1st year apprentices in preparation for an exam the following day. If it wasn’t for channels like this, I’d never pass a test. Thank you.
Thoroughly represented on PowerPoint and explained. Helped me comprehend and apply the 2012 IFGC methodology to calculate a rough-in we had to do on a New Orleans, multi-unit structure. Tom Jones, ColdAirNOW!. Thank you for the time take to prepare this excellent presentation.
Thank you so much for your videos! Ive just finished school and am a apprentice now going for my journeyman gas license in a few weeks. Your videos have really helped simplify gas piping compared to school. Thanks again!
Thank you!! First time I took my Master Gas fitter exam I failed, it shows you what you got wrong and I got 11/12 on gas pipe sizing because I watched this video a few times!! I appreciate you making this! I passed the Master Gas fitter exam the 2 time I took it!
This one is part of the gas code test prep that I am putting together. It won't cover all codes tests for every area, but will a good general prep. Thanks for the support. GFM
That methodology is a clever and simplified way to get a consistent pressure drop per foot of pipe throughout the system. Once you understand that, it all makes perfect sense.
Thanks gray furnace man! I guess i have been doing it wrong and actually oversizing since i have been useing the longest length for the sizing of the branches and the drops as well. Thanks for your help.
Thanks for the piping info. You would be shocked at what I've seen under some houses. Who ever installed some of this stuff should be shot, half of it doesn't even pass gas code.Some would take 1/2 inch from the main branch, and that would be it. Makes you wonder how any of their gas appliances work. Thanks again for the info, this always helps especially green horns like me coming up in the trade.
Great demo this will definitely help our apprentice who are trying to pass there journeyman test and help the guys in the field in the sizing of small to large size gas systems. Have you ever thought about doing a video of installing and sizing of a 2-lb gas system with regulators to reduce the sizing of black pipe used in large residential homes using several million BTU's. Thanks Your Help is Appreciated
Correct me if I'm wrong, but the sizing chart goes off CFH so for example on the 2nd section where you had 250k btu and you convert to CFH it comes to 228 CFH you could actually use 1".
Excellent & simplistic instructional! Thank you! Also thank you for not pandering for thumbs up, subscribing, & "hitting the bell notification so the RU-vid algorithm can..." make you more $$$$! You got my thumbs up, now to investigate home owner permit requirements (ain't no dummy!).
Was directed to this video by a comment under another on the same topic. "Grayfurnaceman IS the man!" Learned a lot here and found that pipe sizing isn't a guessing game. Does temperature effect flow through an above ground natural gas pipe to an outdoor grill, and is ambient temperature taken into consideration, along with all the other factors, when determining pipe size. Thanks for posting all the educational videos. No telling how much mony you have save folks - not to mention possibly lives too.
Question on gas pressure. Probably not the most appropriate video to comment on. I had an issue with about a 40 year old furnace (NG). The property originally had this one furnace and a gas meter set at 7"WC. About 15' of 1" pipe to the Mechanical area and the Tee'd a d reduced to 1/2" to go to the 77,000 btu furnace and 30,000 btu water heater. An additional added a new kitchen with gas stove. Followed by a third addition which added a second 60,000 btu furnace. I was called to look at the original furnace because at beginning of this heating season the owner found it to light but then would shut off moments later. I determined the controls to all be working correctly and checked the inlet gas pressure and found it to have about 7-8"WC without the furnace running and would drop to about 6 while it was in operation. Within 30 seconds of flame you could visually notice the flame fizzle out and then the gas valve would shut off at a flame fail. The furnace spec indicated a minimum of 4.5"wc and max of 10.5. Manifold spec was 3.5. My testing of gas pressure always showed gas pressure within range on inlet and manifold sides. I checked the orifice and burners yet come to the conclusion that the gas valve must be faulty. Instead of replacing the gas valve the owner just wanted to replace the furnace being it was as old as it was and this being a rental property. I put new furnace in and found it to do the exact same thing as the original one.. gas pressures all read within spec. Manometer was zeroed out numerous times as I did when checking the original to be absolute certain I was getting the most accurate reading of gas pressure. I went as far as turning the gas off to the other furnace and water heater..But each time the gas pressure was and remained in range yet still the furnace flame would fizzle out and the go out on flame fail. I'm using a new UEI two port manometer. Is it possible that this just isn't picking up a drop in gas pressure fast enough? All I can figure is that there simply isn't enough pressure being the meter is only set to 7"WC and there just simply isn't the volume available. Even though I don't have the readings of too low of gas pressure at the furnace to support that.... ????? ... plus doesn't explain why there hasn't been any issues up until now.. the 2nd furnace operates just fine. Right now the plan is to have the gas company replace the meter with a 2 psi and we step it down right at the furnaces and water heater as well as replacing some of the old blue pipe. Curious if you have ever encountered this?
This is a good example and makes perfectly logical sense to me, but up here in Canada we calculate it slightly differently. We still go by the longest measurement and total BTU. But we must then use the longest branch line measurement to size every other branch line appliance coming off that system, and we're not allowed to count those 2 subsections as separate unless they're tied in within 2' of the meter. I think it all boils down to maintaining a proper pressure drop that doesn't exceed 2' w.c. It's amazing how complicated something that seems so simple has gas guys arguing and scratching their heads. Good video.
The text I used is the IFGC. As is normal, not all jurisdictions use the same source. And yes, we do seem to argue about this a lot. Thanks for the thoughts. GFM
grayfurnaceman Whoops. I meant a pressure drop not exceeding 1"w.c., not 2"w.c.. We use the B149 CSA code books up here... Yeah it really can be annoying. For example, we could have a LMR of 70' and have a branch line for a small BTU appliance within 3 feet of the meter and only 2 feet of a branch and STILL have to calculate that appliance by the LMR of 70", which is nuts when we're so close to the regulator.. The majority of guys don't follow these rules to the letter when it really sometimes seems like overkill.
bodybuildingking I think sometimes you see "regulation creep" in these charts. Each reviewer ups the the restrictions. Our pressure drop is .5 in wc. GFM
Our normal chart is 7-14" w.c. with an allowable drop of 1". But we do have another chart for a system under 7" which then demands a pressure drop not any greater then .5. It's kind of tricky since most residential places are pretty well bang on at 7".
Thank you for this awesome tutorial. It helped me to calculate my pipe size for an additional pool heater to my existing gas appliances. I calculated that I have sufficient pipe size in my grey pipe to just add PE gas pipe to the end of one of my existing branches, vs. adding a new branch directly at the meter. One question that I am still stuck on is total gas supply being enough for all my appliances. Can anyone lend their expertise in this area? It would be much appreciated. Meter is an American Meter AC-250 that supplies 250k btu total. So American Meter AC-250 (250,000) - Gas Luxaire Furnace (100,000) - Water Tank (45,000) - gas dryer (25,000) - Gas Range (50,000) - New Gas Pool Heater (125,000) puts me well over the 250,000 supplied by the meter (a total of 345,000) in appliances. A couple of things I considered whether I need to have a new meter swapped in for more capacity: When the pool heater is running in warmer months, I won't be simultaneously running the gas furnace, so I'd be "exchanging" the 100,000 furnace use, for a 125000 pool heater and then my meter will allow this delivery (245,000) total when furnace is out. My stove calculation came right from the stoves manual for the burners and they didn't include the oven part of the stove, just the 5 burners at max. Our outdoor grill is propane, so not a factor. Sorry for the long post...wanted to cover every factor. Thanks all.
@@johngriffith8999 It is meant for determining the correct size piping in accordance with the IFGC. You can use a screen shot for your diagram if this is for code issues. GFM
Great class, informative too. What is code as far as unions go? Can they be inside the cabinet, or must they be outside the cabinet? I had someone tell me, drip legs, are no longer required, because the gas is so clean, compared to yesteryear. Lets say I’m at the unit and want to drop the pipe size. Does it matter what side I install the gas ball valve on. I mean the smaller size will do just as well as a large one, and be cheaper to boot! What is code about painting and color. What about pipe support distances… I heard high pressure gas pipe was painted “Red” (25PSI) I need DATA!!!!!!!!! FEED ME!!!!!!
Drip legs are part of the IFGC regs as far as I know. However, the only thing I have ever found in a drip leg was cutting oil and threading chips, so they could do away with them. Use the smaller valve as long as it is not smaller than the input pipe to the appliance. The only color I have seen for gas is yellow. I will be doing more on gas codes. I have just started a series on passing gas codes tests. Hope this helps. GFM
I used the exact same chart you used , I am a master plumber in texas and I was taught a different way , and it works great and easy for me . I am dyslexic . I get the total developed length then go to the furthest fixture and go backwards to the meter . I noticed I up sized every pipe compared to yours . I understand your method completely but I think here in texas they want you to be on the safe side I don't know. I used your method with great ease but came up with smaller pipe sizes . I do think my way is easier to learn and do you just go backwards . instead of forwards .
I got a question for you, if you really oversized the runs going into a furnace, will this effect the input BTU firing rate or will it make no change? Lets say for example you had a 4 inch pipe reduced down to a 1/2 pipe going into a 88,000 BTU furnace? and the furnace manifold pressure is set at factory specs. And assuming 7" WC going into the furnace.
great video.... I'm looking to ADD pipe to the existing system in order to add a garage heater and a manifold for future appliances. So that must be a whole extra calculation. I'm guessing that I could look at each of the calculations for the existing system and look for any surplus BTU's that the existing pipes are capable of moving that are currently being used? And if the existing pipes are close to their maximum BTU carrying capacity, would I need to add my new manifold directly off of the gas meter area?
Fyi for better or worse those of you taking the TSSA exam in Ontario, the answers are based on the longest run. You keep the longest run code zone when calculating the shorter run.
@grayfurnaceman hello good sir, I was just wondering do you add 5 foot to your length for each fitting? like a 90 or tee. is that a rule, or is that with propane, or is it for both, or not a rule at all. thank you for your time.. great video
Great vid. There is one thing I can,t seem to understand. When you refer to the chart to look up the BTU, the chart column label is cubic feet per hour. Is btu equal to cubic feet per hour? Thanks
The chart actually calculates cu ft per hr. If you have a local BTU per cu ft of 1000 BTU as most areas do, its an easy conversion. If your local BTU are different, you must adjust.
The chart is designed for volume of gas. The appliances is calling for so much volume of gas inside of the pipe per length. Get chart is laid out for distance and btus the appliance is calling for. I hope that helped.
Question for you. I have 70’ for my furthest distance. However, I want to install a 199,000 tankless water heater. The tankless water heater only has 3/4” connections. Using the chart, 3/4 is not supposed to be utilized even in a branch off of a 1-1/4 just to supply the water heater. The chart would state that I would need a 1” connection to the water heater. How do you get around this to meet code? Do you just reduce down to 3/4” close to the water heater?
