Questions & Answers

Frequently Asked Questions

40-31 questions

40. what is the piping convention for installing tongue and groove flanges?
39. what a pipe terminology means "under powder longitudinal welded pipes"
38. what it the difference between piping iso's and piping arr?
37. hello, my friend just send your website to me
36. astm a333 material, shall be employed for low temperature services
35. what are backing flanges?
34. understanding bellow seal(ed) valves
33. i appreciate all the work and research that you've done
32. special flanges-orifice flanges and plates
31. what is the different between api598 and api6d?

Question 40.. what is the piping convention for installing tongue and groove flanges?

Good morning,
One question, What is the piping convention for installing Tongue and Groove flanges?. Does the tongue go upstream or downstream? Is this orientation specified anywhere?.

Steve Miller

Answer from Werner Sölken

Hi Steve,
Good question which many possible answers.
I have worked for a company where many TG flanges were used, and where nearly all male ends point in the flow direction. Except for Valves, both sides of their Valves were female.
I have searched many ASME and API standards. I have found no rule that defines a orientation or flowdirection for TG flanges.
I think every company makes their own choices, and no official specifications have been made.

greetings Werner


Question 39.. what a pipe terminology means "under powder longitudinal welded pipes"

Hi Werner,
I have a question about what a pipe terminology means "under powder longitudinal welded pipes". What does the "under powder" mean in laymen' terms.
You help in this would be much appreciated.

Best Regards
Peter Kirkham

Answer from Werner Sölken

Hello Peter,
Powder welding is a non-fusion form of gas welding in which a modified oxyacetylene torch serves as both a powder supply and heat Reference(s).
The melting point of the deposited powder is below that of the base iron and when the base iron surface reaches a certain temperature, the deposited powder coating melts and "wets" the casting surface.
Subsequently the weld is built up as the preheated powdered alloy continuously melts as it impinges on the wetted surface.
Powder welding does not fuse the base iron and the success of the weld is determined by the development of a diffusion bond.
Powder welding has several limitations. It is slow, expensive and is restricted to horizontal welding. Although the casting is not heated to its melting point, sufficient heat may be applied to cause distortion in complex castings.
Powder welding is used for defect repair, cladding and joining high alloy irons.

Check out Ductile Iron Society

greetings Werner


Question 38.. what it the difference between Piping Iso's and Piping Arr?

Hi Werner,
Very nice website. Helps me a lot and always in my favourites folder. Thanks for sharing your knowledge and experience with us. Just some small questions.

  1. What it the difference between Piping Iso's and PIPING ARRANGEMENT - Isometric Views.
  2. In our company we also have some drawings called piping plan. It is basically a plane drawing for the piping system. As I did not find that on you site, I am not sure is it common or just use in our company.
  3. There are 2 tables on.. . You mark.. Pressure-Temperature Ratings for ASTM Group 2-1.1 Materials Working pressures by classes, PSIG.

But I think the unit is bar not psig. Can you take a look at it?

Bill Gu M.Sc.

Answer from Werner Sölken

Hello Bill,
Thanks for your compliments on my website.

I have corrected the error to "Working pressures by classes, BAR"; thanks for the tip.

For the difference in Piping Iso's and Piping Arrangements, see main Menu "Docs".
A piping plan is similar to a piping arrangement and is used almost everywhere.
Soon I will show additional drawing examples.

greetings Werner


Question 37.. hello, my friend just send your website to me

Hello, my Friend just send your website to me.
By just scanning you first page, i can tell this site made by a specialist. Nice quality presentation drawing. It is a perfectionist style way, it's like a Japanese specialist that it has quality and a there is a heart behind in it. I have been searching to many website about piping and non of them satisfy me. Good thing i have a copy of piping drafting rev 2. Which guide me the basic understanding of piping.

Imagine by just having PID, Process data sheets and a Plot Plan, I can start making my design. I have been involved from Feed to detailing and it's a nice experience. It is direct 3d design. Unlike my present company now which is in the middle east. First we do it in auto cad. It's like making a 3d first just in your mind and reflect it as piping arrangement drawing...It was nice really.

It seems like to me that being in a piping engineering is a stressful one, it will make you old faster specially working with tight schedule.
But now you give me inspiration because you reach the golden age i guess and made a beautiful website and seem you enjoyed it.

Thank you and regards,

Answer from Werner Sölken

Hello Juan,
Thanks for all your compliments.

In the article about the Author of this website I write.. I have tried to make a website with a clear structure, "what your click is what you get".

I also try to write articles that give a user a certain base on a topic. It is not always easy to define a subject well.
I do not know who will be reading a article; is it someone with extensive experience? or is it a beginner? or is it?... etc. etc.

Well, I'll continue to do my best to satisfy everyone.

greetings Werner


Question 36.. astm a333 material, shall be employed for low temperature services

Dear sir,
1) As per ASME Sec II Part A, ASTM A 333 Grade material, shall be employed for Low temperature Services. ASTM A 106 Gr.B Materials shall also be used if the the temperature is ranging between -20 to 420° Celcius.
Instead of SA 333 Grades why can't we use SA 106 Gr.B or if there any specific application for SA 333 Grade Materials. If so, what are the services that employes SA 333 Grades as its Material of Construction.

2) Seam Pipes, Seamless Pipes, ERW Pipes are termed by the manufacturing process. Based on the manufacturing process will the Allowable stress value of the Materials differs among the same materials (say SA 53 Gr.B)

Thanks with Regards
Mandela I.Truman

Answer from Werner Sölken

Hello Mandela I.Truman,
Depending on the browser you use, remove the history regularly. I add items daily, but I do not want to do this with various icons to indicate.

For several days I tell on my website a few things about ASTM A333, perhaps you have not read, or you can not read.
Look at ASTM A333 on my site. At the bottom of that page you will find an explanation.

If that explanation is not sufficient, I ask you to think about spheres where gas (Propylene, LNG, etc.) is stored. Why we used killed steel?...the answer is already given.

greetings Werner


Question 35.. what are backing flanges?

Dear sir,
While designing the piping system for Dosing system,we had noticed that,we make use of Backing Flanges. We are not aware of this and till now, I'd never used anywhere.
Could you please send some details about the Backing flange,its purpose and its applications.

Thanks with Regards
Mandela I.Truman

Answer from Werner Sölken

Hello Mandela I.Truman,
Check out Lap Joint Flange on my site. On that page you will find an example of a backing flange.
Backing flanges are loose flanges that in piping systems can be applied, and they are available in many different versions. Itself the flange is not welded or fixed in any way. It is free to spin for clean alignment with whatever it is joining to.

greetings Werner


Question 34.. understanding bellow seal(ed) Valves

from Ali Sabeti

Dear Sir,
I am one of your really valuable website user. I have read Valve topic but the section BELLOW SEAL(ED) ValveS does not make scence. Please send me some figures about this section to help me understand it clearly as other parts.
Yours Faithfully
Ali Sabeti

Answer from Werner Sölken

Hello Ali,
Check out bellow sealed Valves on my site.

greetings Werner


Question 33.. i appreciate all the work and research that you've done

Hello Werner,
I just stumbled across your website today while searching for info on ASTM standards for pipe-fittings. Your website is a god-send! I work in supply-chain and assist our maintenance planning dept. with the ordering of pipe, Valves, and fittings. I appreciate all the work and research that you've done to make life easier for people like me.

Thank you,
Chad Andriowski / Canada

Answer from Werner Sölken

Hello Chad, sorry for my late reply.
I do not know what you meant by.. people like me (joking). Believe me, experienced engineers and other experienced people occasionally look at my website.

greetings Werner


Question 32.. special flanges-orifice flanges and plates

Hi Werner hope you are fine. I have asked you a question before regarding piping isometrics and hope you find some time to clarify my doubt.
I also found that you mentioned ASME B31.3 para 328.5.4 in flanges - special flanges-orifice flanges and plates. Why it is mentioned is it a typing error or is it relevant to that flanges. Please clarify.

You have mentioned the same std (ASME B31.3 para 328.5.4) in specials -reinforced branch connections which I understood.

The best thing I like about your website is the pictures which clear ones doubt for example the cross section of orifice flange in flanges -special flanges. Sharing the knowledge earned freely is a very noble thing and I really appreciate and thank you for your efforts.

with regards,
Deepu Varghese

Answer from Werner Sölken

Hi Deepu,
ASME B31.3 para 328.5.4 has nothing to do with orifice plates and flanges, mistake of mine.
Thanks for the tip and thanks for your other compliments.

greetings Werner


Question 31.. what is the different between API598 and API6D?

Dear wermac,
Could you please tell me what is the different between API598 and API6D, and we can use Pressure test API598 instead of API6D for Valve?
I look forward to hearing you soon.
Thank you for your help.

Best Regards,
Vu Tat Tuan (Mr.) / Viet Nam
Mechanical Engineer
Engineering Department - PTSC MandC

Answer from Werner Sölken

Hi Mr. Vu Tat Tuan,
API 598 covers inspection, examination, supplementary examinations, and pressure test requirements for resilient-seated, nonmetallic-seated (e.g. ceramic), and metal-to-metal-seated Valves of the gate, globe, plug, ball, check, and butterfly types.

API 6D International Standard specifies requirements and provides recommendations for the design, manufacturing, testing and documentation of ball, check, gate and Plug Valves for application in pipeline systems meeting the requirements of ISO 13623 for the petroleum and natural gas industries.

Occasionally the chemical or refinery Valve specifier will see reference to API 6D - "Pipeline Valves". This document is a thorough standard covering the design, materials and dimensions of Valves for pipeline service. The most common reference for non-pipeline use are the testing requirements which differ slightly from API 598. The primary difference being 6D's zero allowable leakage on closure tests. Since most of the Valves built to API 6D are resilient seated, this is no problem, however when the test standard is applied to metallic seated wedge gate, globe or Check Valves, compliance can be difficult.

greetings Werner



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