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Understanding Terms in Piping System Part 1

You always need to find a bright side of a simple task. For example, copy, paste, and modify piping material specification, specification for coating and wrapping, and piping design. Yesterday I did this! At the first time I thought this was a very ridiculuous task yet unimportant. I’ve ever seen a drafter did this. But I found a bright side of this task which is a chance to learn. 

My objective is very simple. I want to understand what other people are talking about, when piping is their topic. I want to undestand the terms and imagine what they are looked like. That’s all. I think this is a good step to learn about piping.

Piping system has a lot of terms. So, it is impossible to write and describe all of them. In this post I want to share a brief explanation about piping system. As long as I understand them, it’s oke 🙂


Pipe joints are used to put pipes together. There are several methods of pipe joints, so that the selection process is very critical.

You can learn about piping joints by downloading the handbook below. I read several parts of the book and I wish you can get some understanding about the topic.

Download Piping Joints handbook.

Before you go into selection of piping joints, you need to decide to which documents you refer to. ANSI (American National Standards Institute) and API (American Petroleum Institute) has several standards of pipe joints.

ANSI B1.1 Unified Inch Screw Threads

ANSI B1.20.1 Pipe Threads, General Purpose

ANSI B16.5 Pipe flanges and Flanges fittings

ANSI B16.9 Factory made wrought steel butt welding fittings

ANSI B16.11 Forged Steel Fittings, Socket Welding, and Threaded

ANSI B16.20 Ring-Joints Gaskets and Groves for Steel Pipe Flanges

ANSI B16.21 Non-metallic flat gaskets for pipe flanges

API 601 Metallic Gaskets for RF Pipe Flanges and Flanged Connection

API 6A Specification for Wellhead and Chrismas Tree Equipment

A lot of terms, huh? That’s ok. Let’s start learning!

For your general understanding, joints in the piping system can be made by using butt welding, socket welding, flanges, or screw fittings.

BUTT-WELDING is the process of joining two pieces of material together along a single edge in a single plane.
Example of butt-welding

SOCKET WELD FLANGE is a type of pipe connector that incorporates a socket into which a pipe is welded.The socket weld flange was designed to work on small size, high-pressure pipelines.

PIPE FITTINGS connect to pipes in one of two ways: by threads or by slip fit. 

Stainless steel pipe fittings
Stainless steel pipe fittings



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