High-Pressure Gas Line Sizing - Video 2: Sizing The Gas Line

[@yetongzheng9877]

My teacher said 2 hours class for it, students are confused, lastly he posted this video link, I just spent 10 minutes, it works better than 2 hours,

[@troygibson3831]

Great video Thanks! 👍

[@sneakynut9107]

your videos are very helpful and im always coming back to your channel to study. I ran into a pipe sizing question on my G2 test that stumped me. It was a high pressure system with low pressure regulators that were supplying 2 or more appliances. How would i pipe size before and after the regulator? like still use longest run of the whole system? Do i calculate the BTU load of the appliances after the regulator with the total of the high pressure side? sorry for the long question, anything will help

[@MathematicPlumber]

For sizing the high-pressure side, watch both these videos again. That is 100% explained. For the low pressure side, longest run is from the regulator (where HP is regulated to inches water column) to the most distant connected appliance. The btu load will only be regarding what that regulator is serving. This is standard low pressure sizing with no extra tricks.

[@sneakynut9107]

@@MathematicPlumber on the high pressure side, is it the longest run to the low pressure regulator or longest run of the entire system?

[@MathematicPlumber]

@@sneakynut9107 most distant pressure reg is your longest run

[@mysticskills9131]

@@MathematicPlumberthanks for explaining this in a comment this is the only thing that wasn’t clear in your video you’re really helping out a lot of people with these videos you make, cheers man

[@mysticskills9131]

@@MathematicPlumber(I’m talking about sizing the low pressure side in a high pressure system not this guys second comment) from what I understand if a regulator has 3 appliances downstream of that regulator, then you take the longest run from that regulator to the farthest appliance in that section

[@davequesnel8740]

when calculating longest length factoring fittings, when encountering a reducing T through the route, (2" to 1" for example) which table size T is factored ? (2" would be different than 1" equivalent length) in this example you count it as 2" what if additional turns were reduced? or straight-through BUT reducing ? also if calculated from appliance back to meter, then the (reduced) fitting would be sized differently, assuming proper method would exclusively have to be from meter-to-appliance regulator direction

[@MathematicPlumber]

Reducing Tee EL: the gas code gives us no clarification on this other than Clause A.4 which gives the source of the table A.16. The table is from: Sabin Crocker, Piping Handbook 4th Edition (from 1945) The table found in this book further clarifies reducing tees. When a tee is reduce to half its size the EL is also reduced by half. Therefore, in your example, you would just use the table value for a 1" tee, because it is half. (Not exactly, but close enough.) In my example, I bushed down a 2" tee, so I'm still running through a 2" tee and I will use the 2" tee value.

[@MathematicPlumber]

I do not understand your second question here. Please elaborate

[@davequesnel8740]

thanks, i understand using the smaller of the T outlets as the T size, however i dont understand the logic/ difference between a bushed down T and a reducing T (in the cense of EL) you calculated it as 2" even though it reduced in size. my second question referrers to sizing T's as well, ( basically, is a reducing T sized by its larger opening? or smaller opening? in your example it appears to be sized by direction of flow (which size is entered first) @@MathematicPlumber

[@davequesnel8740]

so for example, is a 1" tee reduced to 3/4' EL sized as a 1"? or a 3/4"? i feel it would be weird for there not to be a clause addressing this, and weird that I would be the first person to ever ask this question ( as it would be critical to accurate EL fitting calculation

[@davequesnel8740]

so appears (by your explanation) if a 1" T reduces to 3/4" its EL is a 1" T if a 1' T reduces to 1/2" T ... then its EL is 1/2"

[@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?

[@MathematicPlumber]

Given this is low pressure natural gas piped through black iron pipe: No. Even though there is only 10' of ½" pipe, you now are only good to 86k btu. You need 1" pipe to meet that demand.

[@vickyr8360]

Mathematic Plumber buried Polyethylene pipe is used

[@davequesnel8740]

watched the High pressure sizing video 30 times, doing a CSA Red Seal sample test study tool online, EVERY SINGLE high pressure sizing exercise i do is incorrect, (50 in a row) low pressure correct every time, im about to just give up & concede i WILL FAIL this section of the test, something is amiss with the test or the methodology to calculate. the only difference is the sample questions are using "welded iron pipe" and " forged T's" appears there's a column for welded elbows & forged T.s which i am using for the calculation

[@davequesnel8740]

I have pictures of the question & their answers, but cant upload here, but ive spent endless hours trying to calculate

[@MathematicPlumber]

Do not put any stock in the practice test, it is garbage. The best thing you can take of that test is to see how the authors formulate their questions. If memory serves correct, there is one or two high pressure sizing questions on the red seal. They are not overly complicated. If you fail the test based on high pressure sizing, then you have major issues in other areas. Judging by your intelligent questions, I highly doubt that will be the case. I am about to give you the most important advise I can give you: do not sweat the little details and do not over complicate things. Both of those things will lose you marks on your red seal. The red seal is written from a practical stand point, the authors are not trying to trick you with fine details. The test is designed to gauge if you have a reasonable understanding of the code book and a reasonable understanding of practical application. Remember, high pressure gas line sizing is almost always done by an engineer and then put on a blue print. This part of the course is so you can understand how they get top their sizes. You have a clear understanding of that already.

[@davequesnel8740]

thanks for insights! will follow that ideology, i do intend to write a nasty letter to this online sample testing utility in true Canadian fashion, suggesting a serious audit of the test questions and diagrams they are providing, as they are loaded with spelling and grammar errors, including absurd diagram and calculation errors.

[@JosephB]

Could you do this in the way where you take your LMR and just add the fittings to it right away so you dont have to go back and check? you can just size things according to your LMR with fittings right from the beginning so you dont have to go back and check?

[@MathematicPlumber]

You can take an educated guess yes. But you don't know exactly what size of fittings you will be using, so it could be different. If you are ok with slightly over-sizing your system, you might have some luck with what you are suggesting. If cost of material is a big concern, it is good to just double check.

[@JosephB]

@@MathematicPlumber ohhhh I see well thank you so much for your educational videos

[@JosephB]

@@MathematicPlumber you wouldent happen to know anywhere I could find some practice questions for this type of pipe sizing would you? I have my g2 coming up and cant seem to find any that i havent already answered.

[@MathematicPlumber]

@@JosephB Unfortunately no, I don't honestly know where you can even look. This is kind of an under represented skill. This often falls in the lap of mechanical engineers.

[@josephhardoon7949]

I have gained a ton from all the venting videos.. Is there anyway to contact you. I'm concerned that i do a job correctly. Commenting here cause this is the most recent video im seeing you uploaded. thx Joe

[@MathematicPlumber]

Here is my email: [e-mail] I check it on occassion

[@JotaroKujo-rm3sn]

Holy I’m still confused