Question and Answer 21-30

Question 30: fantastic website and information source...thank you very much

Dear Werner
Fantastic website and information source...thank you very much for all your efforts to produce the site. It must of taken heck of a lot of work!

Very best Regards
Jeff Horton
Technical Manager CAMBRIAN ValveS Ltd / UK

Answer from Werner Sölken

Thanks for the compliments on my website...and yes it's a lot of work to update a website every day.

greetings Werner

Question 29: duplex uns S31803 vs monel 400

Dear Sir,
In the data sheet of Y Strainer, material of Screen Guide is Duplex SS UNS S31803, but vendor offered Monel 400 material instead of Duplex SS UNS S31803.
Can you give me your advise about this problem?
I am looking forward to hearing from you.
Thanks & Regards!
Nguyen Anh Tung (Mr) / Vung Tau City, SR Viet Nam

Answer from Werner Sölken

Monel 400 is a versatile nickel copper alloy with good strength and toughness, combined with outstanding corrosion resistance, while UNS S31803 is a 22% chromium, nitrogen alloyed duplex stainless steel with high general, localized, and stress corrosion resistance properties in addition to high strength and excellent impact toughness.

Chemical Composition % Monel 400

  • Carbon (C) = 0.3 max
  • Maganese (Mn) = 2.0 max
  • Silicon (Si) = 0.5 max
  • Sulphur (S) = 0.024 max
  • Nickel (Ni) = 63.0 min
  • Copper (Cu) = 28.0 min - 34.0 max
  • Iron (Fe) = 2.5 max

Chemical Composition % UNS S31803

  • Carbon (C) - 0.03 max
  • Maganese (Mn) = 2.0 max
  • Silicon (Si) = 1.0 max
  • Sulphur (S) = 0.015 max
  • Phosphorues (P) = 0.035 max
  • Chromium (Cr) = 21.0 min - 23.0 max
  • Nickel (Ni) = 4.5 min - 6.5 max
  • Molybdenum (Mo) = 2.5 min - 3.5 max
  • Nitrogen (N) = 0.10 min - 0.22 max

As you can see, there are important differences in both materials.
My tip: Do not deviate from your specification, and do it only if you have your customer's written consent.

greetings Werner

Question 28: during hydrotesting would the crotch areas expand the most?

Your site is great first of all. I have a question which involves forged tees.
I have a prefab line that has 7 each 30" tees. During Hydrotesting would the crotch areas expand the most?. The problem we are having is the coating delaminated form there almost as if it was stretched. Do you understand my question?
Thank you much.
Chad C. Cuvo
Morrisville US

Answer from Werner Sölken

First, thanks for the compliments on my website.

Do you understand my question?...Yes and No.

Have the Tees internal or external coatings, or both?.
Normaly, after hydrotesting and other NDE, pipes, flanges and fiittings will be painted.

At the moment, unfortunately I can not go to answer your question...I have no more than a mobile in my hands.
Next Monday, I can tell you more...I'm sorry.

greetings Werner

Second answer from Werner Sölken

During Hydrotesting the crotch areas expand the most, is completely correct.

The wall thickness around the crotch must be have at least a factor of 1.3 of the normal wall thickness...I think with a 30 inch tee is not, and that's the problem with your coating.

See the article about "crotch" on my website: wall thickness Tee

greetings Werner

Question 27: i guess you might know what a "dowel pin" is

Dear Werner,
I guess you might know what a "dowel pin" is. Application is flow metering using an Ultrasonic meter. I imagine that the flow profile has to be very quite for an accurate measuring.
(That's why we're using a flow conditionner). Moreover the gap in result of a bad alignement could create turbulences. I think that's why "dowel pins" are required in order to get a smooth alignement betw. several spools and flowmeter.
I'm I right? If you got more information it would be very helpful !
Once again, thanks a lot for your help.
Best regards,
Gilles / Switzerland

Answer from Werner Sölken

Hi Gilles,
Dowel Pins are hardened and precisely shaped pins. They are used to keep machine components in accurate alignment. So, you're right with your conclusion.

The use of dowel pins to guarantee positional security of rotating machinery is not recommended. The use of dowel pins to guarantee positional repeatability is also not recommended.

This is the conclusion of a study made by: Alan Luedeking.
He is the manager of alignment technical support and training for Ludeca Inc.
He can be reached at 305-591-8935 or
For more information on Ludeca, visit

greetings Werner

Question 26: astm a193b7/a1942h, heavy hex, zinc nikel plating with a top fluorocarbon

I'm evaluation for some packages. Our material specs of bolting is : ASTM A193GRB7 / A194GR2H, Heavy Hex, Zinc Nikel Plating with a top Fluorocarbon Coating-Blue Colour (MasterNizcote or Equivalent), And Vendor offered AISI 316 or Black Fluorocarbon coated material.
I'm wondering it's acceptable or not acceptable and If not acceptable, why?.

Vu Tat Tuan / Vietnam

Answer from Werner Sölken

What is Fluorocarbon Coating?
Fluorocarbon coatings are formulated from the family of Fluoropolymers, which includes Teflon® and others and exhibit many of the properties associated with these unique materials.

Utilizing the chemistry of carbon and fluorine, fluorocarbon coatings impart properties not attainable with other organic coatings when applied over suitable substrates: outstanding chemical and corrosion resistance, non-wetting surfaces, exceptional thermal stability, extremely low coefficient of friction and excellent non-stick qualities.

Fluorocarbon coatings can extend the life of moving parts; maintain the purity of pharmaceuticals and chemicals; insure perfect molded parts; reduce maintenance and downtime; improve sales; produce uniform baked goods; reduce the possibility of electrical shock; improve the performance of medical instruments.

Material specs are not there for nothing
In your material specification blue coated carbon steel Stud Bolts are defined. Your customer will have a reason why the bolts and nuts must be blue colered carbon steel. You should not ask yourself whether an alternative is acceptable. Your customer determines what should be used.

Your supplier proposes to use stainless steel bolts with a black fluorcarbon coating.
My tip: Do not deviate from your specification, and do it only if you have your customer's written consent.

greetings Werner

Question 25: i believe that there is a mistake in the chart showing

I believe that there is a mistake in the chart showing the 38" weld neck flange height (dimension "H") in the ASME 16.47 Series B 300 pound class chart. Can you verify and fix (if needed) thank you.

Lorne Henderson / Canada

Answer from Werner Sölken

ASME B16.47 gives the same H size as in my table (see attached asme_b16.47_series B.gif). I have checked the old API STANDARD 605, and there is another height specified and suppliers of these flanges specify the same H size as API 605.
I think ASME has made a small mistake.
Thanks for the tip...I have changed the H dimensions.

greetings Werner

Question 24: use of united states and european standards

I am involved in a project in which components are made in the US using NPT and ANSI dimensioned flanges and fittings.
We will need to connect these items to metric flanges and fittings, pipe etc. in Europe.
Can you point me to the conversion factors necessary to accomplish this? Also, is a DN 32mm pipe and thread the same as a 1" NPT pipe?
I am having trouble understanding the specs and could use the direction. Thank You.

Answer from Werner Sölken

Hi Robert,
Metric pipes and fittings often have different wall thicknesses as ASME (earlier ANSI).
Metric flanges usually have different bolt circles and will not fit on ASME flanges.
Metric thread is not equal to NPT thread, mostly in Europe, Whitworth thread BSP-P or BSP-T (British Standard Pipe) applied. P stands for Plain thread and T for Tapered thread.
I think that's not a good idea to use both standards together.
By the way:
Nominal Pipe Size (NPS) and Diameter Nominal (DN) are dimensionsless designators for pipe sizes.
DN 32 is a designator for pipe 1¼" equal to NPS 1¼ (without an inch symbol)
DN 25 is a designator for pipe 1" equal to NPS 1 (without an inch symbol)

greetings Werner

Question 23 how to install 2 pipes system with 2 difference material

My Question as per Image Below:
 a) How to install 2 pipes system with 2 difference material (refer to image below)?
 b) For Stud, Nuts & Washer material..which spec I need to use?
 c) Gasket Material to use?
 d) How to avoid corrosion problem?

Carbon Steel
Flange Spec/Material : 150# rating & A105N
Stud & Nuts & Washer: A193 Gr.B7 & A194 Gr. 2H & ASTM F436
Gasket :SS/Graphite/SS

Stainless Steel
Flange Spec/Material : 150# rating & A182 F316L
Stud & Nuts & Washer: A320 Gr.L7 & A194 Gr.4 & 316SS
Gasket :SS/Graphite/SS

Spec Break

Hope you can advise and provide reference for my queries.
Regards & Thanks
Zulkaini / Malaysia

Answer from Werner Sölken

Hello Zulkaini,
Your questions concern a so-called piping specification break, in piping terms a "spec break".

A "spec break" happens where there is a change from one significant design condition to another, below a few examples:
- transition from high to low pressure
- transition between high and low temperature service
- transition between corrosive and non-corrosive environments

In your example, the piping system change from stainless steel to carbon steel (or vice versa), where pressure class and gasket material do not change.
The break are two Class 150 flanges, one of CS (A105N) with bolts, nuts and washers for High-Temperature applications, the other SS (F316L) with bolts nuts and washers for low-temperature applications.
For the flange connection, bolts, nuts and washers from both materials can be used, depening on customer requirements.
Corrosion problems: I suspect that your client has thought about, otherwise he would not move from Stainless steel to Carbon steel.

greetings Werner

Question 22: need to find dimensions of latrolets

I came across your site today while searching for dimensions of weldolets. I also need to find dimensions of latrolets. Do you have these available? Or could you possibly point me in the right direction?
Thank you,
Brandon Henson
Product Engineering

Answer from Werner Sölken

Hello Brandon,

Look at the site of: Bonney Forge

greetings Werner

Question 21: mss sp43 Stub Ends with 2 radius

I have to say that my English is very green, I'm from Brazil and here we speak Portuguese.
I need one information: Why we have 2 types of MSS SP43 Stub Ends with 2 radius?
Thank you very much.

Answer from Werner Sölken

Hello Reinaldo,
MSS SP43 has two types of Stub Ends, namely A & B.
A is used with Lap Joint flanges, B is used with Slip On flanges
The Type A has its outside corner radiused to accommodate Lap Joint flanges. The inside corner is square.
The Type B has an outside corner radius small enough to accommodate Slip On flanges that are being used as the Backup Flange. The inside corner is square. Occasionally, if a Slip On type flange is used, chamfers on the I.D. face of the flange are required for a good joint.

greetings Werner

Comment - from Reinaldo

Thank you, Werner!!!

Questions & Answers