How We Calculate the Roundness Percentage of Pipe?

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tolgacelik Member Join Date: Feb 2018 Posts: 5	How We Calculate the Roundness Percentage of Pipe? 02/27/2018 10:19 AM
	Hello, I'm a mech. engineer who started his first project on piping. Because of that I need your help. In this project, we are building a water delivery system inside a tunnel. The pipes are produced in another company. We are doing the montage. The pipe details: DN2500/ 19,05/ X65 API 5L PSL1 4600 kPa I checked the API 5L 45th edition, according to diameter "2500 mm" the roundness is written just as agreed. About the acceptance percentage of roundness is okay. In our contract we agreed 2%. But I couldn't find any formulas about calculation of roundness percentage and we have a discussion here about the calculation of roundness percentage. If you can help me figure out how we calculate it acc. to API 5L and where can I find this formulation in API 5L, that would be helpful. For now, thanks for your help.
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	Pathfinder Tags: API 5L Ovality Pipe roundness

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SolarEagle Guru Join Date: Mar 2007 Location: by the beach in Florida Posts: 33392 Good Answers: 1817	#1 Re: How We Calculate the Roundness Percentage of Pipe? 02/27/2018 11:51 AM
	"API 5L Line Pipe Out Of Roundness Calculations" http://pipeng.com/index.php/ts/itdmotdiam016d/ __________________ All living things seek to control their own destiny....this is the purpose of life
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SolarEagle Guru Join Date: Mar 2007 Location: by the beach in Florida Posts: 33392 Good Answers: 1817	#2 In reply to #1 Re: How We Calculate the Roundness Percentage of Pipe? 02/27/2018 6:57 PM
	Calculate onshore pipeline out of roundness and ovality (API 5L section 9.11 table 10). Out of roundness is the difference between the maximum and minimum diameter of the pipe. API 5L ovality is calculated by fapi = (Dmax - Dmin) / (Dmax + Dmin) = OOR / (2 Davg) DNV ovality is equal to 2 x API ovality. All tolerances should be entered as positive values. For line pipe with diameter D < 0.0603 [ m ] the out of roundness is included with the diameter tolerance. For line pipe with diameter D ≥ 0.2191 [ m ] the out of roundness may also be calculated from the inside diameter. For line pipe with diameter D ≥ 1.422 [ m ] the out of roundness tolerance is to be agreed with the supplier. Tool Input Dmaxu : User Defined Maximum Diameter Dminu : User Defined Minimum Diameter D : Nominal Diameter Dau : User Defined Out Of Roundness Allowance Dxu : User Defined Out Of Roundness Fraction pipetype : Line Pipe Type t : Nominal Wall Thickness toltyped : Out Of Roundness Tolerance Type Tool Output D/tn : Diameter Over Wall Thickness Ratio OOR : Pipe Out Of Roundness fapi : API Ovality fdnv : DNV Ovality __________________ All living things seek to control their own destiny....this is the purpose of life
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tolgacelik Member Join Date: Feb 2018 Posts: 5	#3 In reply to #2 Re: How We Calculate the Roundness Percentage of Pipe? 02/28/2018 2:48 AM
	Firstly, Thanks for your help, but additionally ı should ask you another question? Is there any written place about this formula? Because when ı reclaim about this formula they will ask in which norm or which place it is written.
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PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#4 In reply to #3 Re: How We Calculate the Roundness Percentage of Pipe? 02/28/2018 4:03 AM
	<...they...>? __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
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tolgacelik Member Join Date: Feb 2018 Posts: 5	#5 In reply to #4 Re: How We Calculate the Roundness Percentage of Pipe? 02/28/2018 5:04 AM
	The controller
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Codemaster Guru Join Date: Jul 2005 Location: Stoke-on-Trent, UK Posts: 4496 Good Answers: 137	#6 In reply to #3 Re: How We Calculate the Roundness Percentage of Pipe? 02/28/2018 9:43 AM
	I don't want to presume to speak for SolarEagle, but wouldn't it be API 5L section 9.11 table 10 (from his post)? I just tried that on internet and got straight to it. __________________ Give masochists a fair crack of the whip
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tolgacelik Member Join Date: Feb 2018 Posts: 5	#7 In reply to #6 Re: How We Calculate the Roundness Percentage of Pipe? 03/06/2018 3:18 AM
	İt is not from API 5L section 9.11 table 10. İt is just on the internet.
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Hoovyendy Participant Join Date: Jul 2019 Posts: 3	#8 Re: How We Calculate the Roundness Percentage of Pipe? 02/28/2020 12:17 PM
	I think it is pretty useful for your job. However I believe that you can use a percentage calculator that can help you with quick effectiveness and provide an intuitive interface of that. Since I work with percentage systems (I am a financial manager), I prefer to use a percentage calculator. It helps with personal time and that's really important for me.
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