I'm designing a piping system for steam, say with
Design pressure 12 bar(g)
Design temperature 200 degC
Material P235GH

Picking flanges according to EN 1092 is very easy. I just look at the one PN-class at the time until i find one that satisfies my pressure/temperature combination.

But what about other piping parts like straight pipe, bend, reducer, T-piece etc. These i have to calculate case by case according to EN 13480. This is very time consuming.

Where can i find precalcuated pipe classes including all the above components with given pressure/temperature diagrams, as the case with the flanges??

Exactly the reason I feel that we shouldn't be redesigning the process for steam systems every time we develop a new plant which uses steam. Can't we just pull the process requirements from a table or just copy the last plant we did without regard to say atmospheric conditions, plant elevations (one flat, the next built on a slope), feedwater quality...We shouldn't be reinventing the wheel every time we need a new plant built!

From another question at another time.

Piping Specifications
The question:
How to make pipe spec. & what is basic need/data for that?

My answer:
First, let's see if we can clarify which "pipe spec" you are talking about.  You must realize that the term "pipe spec" can be both general and specific at the same time.
Here is most U. S. Companies there might be as many as thirty Specifications that cover piping related issues.  There may be a "pipe spec" for:
•    Piping Specification for Plant Layout and Design
•    Piping Specification for Shop Fabrication
•    Piping Specification for Field Fabrication and Installation
•    Piping Specification for Hydrotesting of systems
•    Piping Specification for Hot Insulation
•    Piping Specification for Cold Insulation
•    Piping Specification for Pre-Engineered Pipe Supports
•    Piping Specification for Engineered Spring Supports
•    Piping Specification for Line Class Material
•    Piping Specification for Valve Purchasing

And the list goes on and on. 
This is a partial list of some of the specific "pipe specs" that are found on most projects.  Included in this list is one that I think you are asking about. 

I think you are asking about "Piping Specification for Line Class Material" or it may be called "Piping Line Class Material Specification" or it may have some other combination of words that mean the same thing.  But it is a very specific "pipe spec" out of a very big family of piping specifications.

Now to your question as it relates to "this" pipe spec.
How to make pipe spec?

"Piping Material Line Class Specification"

This document would have a cover sheet and a written section which would include the following:
- Document Title
- Document Control Number
- Table of Contents
- Statement of Purpose and or Function
- General Notes
- A listing of all the Codes that apply to the material included here-in
- A list of all the Line Classes with basic data such as Commodity, Material, Flange Rating, etc.
- Each of the individual Line Class sheets
- The common vent, drain, and other misc. connection details
- Branch Connection Tables (one or more as required)
- Name of Originator (Responsible person), Date created
- Name and date of checker
- Table of Approval for Issue, (Piping Department, Project, Client)
- Table of Issue History listing Revision, date, what was revised, by who, approval sign-off

All of this would then be issued as a single document.

The second part of your question
What is basic need/data for that?

Data Requirements
There are two sides to this question.  There is the up front data requirements needed to produce the Line Class Specification.  Then there is the output data or, what does each line class need to include?

So, first what is required to start?  You need, as a minimum the following information:
•    A list of every commodity that will be a part of the project.  This means the feed, all products, all waste streams, all utilities and all additives.
•    For each commodity you need the complete chemistry including Toxic classifications and reactions to changes in temperature.  Here in the U.S.A. we have a document called a "MSDS" (Material Safety Data Sheet). These have all the chemical, toxic, medical recovery and other data about a chemical be it a gas, a liquid, a powder or a solid.  If these are available in your country then get a copy for your records of the MSDS for each commodity.
•    For each commodity you need the maximum sustained operating pressure and temperature.
•    For each you need to know of any short term or upset condition that may cause an increase or decrease in pressure or temperature.
•    For each commodity you need to determine the corrosion rate for different (common or special) pipe materials.
•    For each commodity you need to know the projected maximum and minimum pipe size expected for the project.
•    You need to know the location of the jobsite and the full twelve month weather/temperature profile.

When you have collected all this information then you need to spend a great deal of time reading and studying so you can answer every question that will come up.  Don't try to memorize it just remember where to find the material on that issue.
This is just a start.  Now you need to know what Piping Code will be the basis for the project. 
Will the project governing Code be:
•    ASME B31.1
•    ASME B31.3
•    Or some other Code?

Now the next thing you need to know is the Clients preferences and or restrictions.  Things like does the client want to use "Lapp-Joint Stub-End" flanges in certain systems.  Does the client want or not want certain types of valves (and why)?  What about Weld-neck vs. Slip-on flanges? 

Next you need to know the "Design Life" of the plant.  This means you need to know how long the plant is supposed to last before it is shut down or starts to fall apart.  This issue determines the amount of corrosion allowance you will consider when selecting a wall schedule.

There is no doubt more that I have forgotten to include in this first pass.  I will try to add more as I remember.  I also know that by posting this here on the pipingdesigners web site others will read it and ad their wisdom.


The finished "Line Class" pipe spec.

Each of the individual Line Class sheet might be created as a spread sheet in a Microsoft Excel Work Book.  One spread sheet for each Line Class.
Across you might have the following column headers?
•    Item
•    Nominal Pipe Size (inches) or (Metric)
•    Schedule (Wall Thickness)
•    End Type
•    Description (This is a simple description of a piping component not a full purchase description)

Vertically the first column (Item) will be divided into "Pipe", "Fittings", "Flanges", "Gaskets", "Bolts" and "Valves"
With-in this column the "Fitting" section and the "Valve" section would be divided to cover the various items normally required based on size. 
"Fittings" would include:
•    90 degree ELLs
•    45 degree ELLs
•    Straight TEEs
•    Reducing TEEs
•    Caps
•    Unions
•    Etc.

"Valves" would include:
•    Gates
•    Globe
•    Check
•    Ball
•    Butterfly
•    Plug
All of these valves would not be in every Line Class.  So which valves does each line class really need?

Other information that needs to be included on a line class by line class basis includes.
•    Basic Construction (2" and smaller Screwed/ 3" and Larger Flanged and Butt welded, etc)
•    Flange Rating (150# RF)
•    Temperature Limits (Minus 50 degrees F to Plus 500 degrees



This is a lot to worry about, and it takes a very special person to do it right.  Also it is a full time job not one that someone does as a side line in their spare time.

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