Questions & Answers

Frequently Asked Questions

130-121 questions

130.	is it better for my career to do api 570 course
129.	how to define the safety distance of hydrostatic testing?
128.	testing of valves
127.	"doughnut" of 2inch pipe
126.	what is the different between ARC valve and ARV valve?
125.	you indicate a reference weight, but this is relative to witch material?
124.	is it missing or is it somewhere that I just don't see?
123.	what is the actual jont type for this sweep olet joints?
122.	what are the reason for using 2 welders?
121.	what type of support is best suited for this kind of job?

Question 130.. is it better for my career to do api 570 course?

Nice website developed by you. I got all topics from your website. Its very good website for new piping engineer like me. I am working in piping engineer in waste water treatment field.
I want to also ask you one question that, Is it better for my career to do API 570 course? I have 3.5 years of experience in this field. I requested to you to guide me on brief. I am very thankful to you.

Thank you and regards,
Samir ahmed (india)

Answer from Werner Sölken

Hi Samir,
I can be difficult assess what suits you, but an API 570 course, is a basic for each piping engineer.

greetings Werner

Question 129.. how to define the safety distance of hydrostatic testing?

Hi Werner
Thank a lot for your LinkedIn connection and thank you very much regarding your piping engineering website https://www.wermac.org which is very helpful for reference on my daily work in piping. Please your permission to access it.
Anyway I have a question about piping testing but I cannot write it in your website, therefore I emailed you via LinkedIn.
Currently I am working as a piping testing engineer for hydrostatic and pneumatic. I just wondering how to define the safety distance of hydrostatic testing? This is to define exclusive zone area during hydrostatic testing.
For pneumatic I got already the stored energy calculator then resulting the perimeter, but for hydrostatic testing I don't have any reference/code/standard to define it.
If you have any experience or calculator may you help me?

Best regards
Muhammad Asri Lanti Lali

Answer from Werner Sölken

Hi Muhammad,
The safe distance for people, during a pressure test.. in my opinion, no one can give a reliable answer.

See my answer on What is the safe distance for Pressure Testing?

greetings Werner

Question 128.. testing of valves

Dear Sir,
I wanna ask about the test that required for valve?
Is it true that each valve based on the their type have different kind of test?
Could you explain about it! Or give me reference about it.
Thanks,

Regards,
Wali Riansyah Z
Jr. Piping Engineer

Answer from Werner Sölken

Hi Wali Riansyah Z,
Yes it is true that each valve based on the their type have different kind of test.
References can be found in the various standards of the American Petroleum Institute (API).
See also Valve standards of the American Petroleum Institute (API)

greetings Werner

Question 127.. "doughnut" of 2inch pipe

Need to build a 24 inch diameter "doughnut" of 2inch pipe.
is there any elbows or 180 bends that can be used to do this or is it a special order project.
Lacke Westman
Welder Foreman

Answer from Werner Sölken

Hi Lacke,
Here in the Netherlands and I know some companies that (almost) every radius of pipe, can make for you.
I'm sure in your country, many more companies can do what you asked.

Welding bends together.. Do not do it, because specialized companies do it for half the cost that you need.

greetings Werner

Question 126.. what is the different between ARC valve and ARV valve?

Dear Mr. Werner,
I wanna ask you what is the different between ARC valve and ARV valve? Are they same?
how Automatic recirculation valve works?
Thanks and Best Regards
Khalid Said Al-arimi

Answer from Werner Sölken

ARV valve stands for Automatic Recirculation Valve.
An automatic recirculation valve (ARV) is a multifunctional valve whose primary purpose is to ensure that a pre-determined minimum flow is assured through a centrifugal pump at all times.
This is important as centrifugal pumps suffer from over heating and cavitation and can be permanently damaged if they run dry.

ARC valve is the abbreviation for Automatic Recirculation Control valve, and ARC® is a registered name of Yarway.
The function of this valve is the same as that of a AR valve.

Soon I will write an article about this type of valve.

greetings Werner

Question 125.. you indicate a reference weight, but this is relative to witch material?

Dear Mr. Werner Sölken,
I'm a student and I'm using your web site as my personal reference to get to know pipes and fittings.
I read this page and you indicate a reference weight, but this is relative to witch material?
I do not see where it's indicated.

thanks in advance for your kind reply
Claudio Cappellato

Answer from Werner Sölken

The page you mention, is in accordance with the ASME standard B16.9.

The standard covers overall dimensions, dimensional tolerances, ratings, testing, and markings for wrought carbon and alloy steel factory-made buttwelding fittings of
NPS 1/2 through 48.
It covers fittings of any producible wall thickness. This standard does not cover low pressure corrosion resistant buttwelding fittings.

See MSS SP-43, Wrought Stainless Steel Butt-Welding Fittings.

If you want to know the weight, for example, an aluminum or titanium fitting, flange or otherwise; I'm not your address.

greetings Werner

Question 124.. is it missing or is it somewhere that I just don't see?

Hi, I can't find the thickness, "t" on the following web page for your reducers.

https://www.wermac.org/fittings/dim_reducers.html

Is it missing or is it somewhere that I just don't see?

P.S. I love your website's appearance - I like the colors, and layout - it looks very professional, and everything is easy to see - good job!

Answer from Werner Sölken

thanks for your compliments on my website.

Wall thickness (t) must be specified by customer; see the last table at the bottom.
Perhaps I should make this more visible.

Imagine, you have a project with pijping diameter of NPS 1/2 to NPS 6, in carbon steel (ASTM A106, A105, A234, etc.)
What is important to know?
Precisely, the wall thickness of the pipe.
Let's say, NPS 1/2 to NPS 1.1/2 is schedule 80, and NPS 2 and above is schedule 40.
If you want to specify the wall thickness for a reducer, the wall thickness of the pipe is decisive.

On page
https://www.wermac.org/pipes/dim_pipes.html
you will find what you are looking for.

greetings Werner

Question 123.. what is the actual jont type for this sweep olet joints?

Respected sir,
We have one sweep olet welding done in our fabshop and as per asme B 31.3 requested for RT. In daily welding report i put butt weld on joint type. But my client refuse to accept this and he is telling its an olet joint. What is the actual jont type for this sweep olet joints?
Thanks and regards
Aneesh kumar .v

Answer from Werner Sölken

Hi Aneesh
See the picture of a Sweepolet®. It seems clear to me that the type of weld is a butt weld.

By the way, the fit up of a Sweepolet®, is one of the most difficult jobs for a pipe fitter.

greetings Werner

Question 122.. what are the reason for using 2 welders?

Respected sir,
As per our project specification more than 12" dia welding we are using 2 welders. Some other project spec.. also telling this. Is any asme or other code mentioning about this?. What are the reason for using 2 welders??
Thanks and regards
Aneesh kumar .v

Answer from Werner Sölken

Hi Aneesh
I've never heard, it is mandatory that a 12inch weld and above, should be performed by two welders. I did some research, at some piping contractors and in API and ASME standards. I have found nothing about this specification.
Ask your client why he specifies that. I would like to know why.

greetings Werner

Question 121.. what type of support is best suited for this kind of job?

Dear Werner,
First of all i really appreciate your work, I find it of great help.
I want to talk to you about a problem i have. I am now designing gas and petroleum metering skids with design temperatures -5 to 80 degrees Celsius and pressures of 5-10 barg, simple configuration but some involving in-line pumps. My problem concerns the supports for this kind of piping. I have seen the use of pipe shoes for guided support which make the piping more flexible and also the use of u-bolts witch give the entire system increased rigidity thus giving a more exact measurement (eliminating vibrations). My concern is that with increased rigidity comes an increased stress on the piping but considering the temperature range i'm inclined to believe that these stresses are low and would not effect the system in time. The question is what type of support is best suited for this kind of job.
I would like to know your opinion on this matter.
Thank you.
Kind regards, Matei Stanciu

Answer from Werner Sölken

Hi Matei, thanks for your compliments for my website.

For Small Bore Piping to NPS 1.1/2 U-Bolts are suitable, from NPS 2 and higher, pipe shoes are better.

Some advantages of U-bolts..