PIPE - CHAPTER 1

INTRODUCTION

DEFINITION:

Piping engineering is all about designing, fabricating and constructing lines for conveying fluids.

IMPORTANCE OF PIPING ENGINEERING:

• To maintain pressure difference (Δp)
• To maintain temperature difference (Δt)
• To maintain flow rate (Δq)

APPLICATIONS:

·               Pipelines carry crude oil from oil wells to tank farms for storage or to refineries for processing.

·               The natural gas transportation and distribution lines convey natural gas from the source and storage tank forms to points of utilization, such as power plants, industrial facilities etc,

·               In chemical plants, paper mills, food processing plants, and other similar industrial establishments, the piping systems are utilized to carry liquids, chemicals, mixtures, gases, vapors, and solids from one location to another.

·               The fire protection piping networks in residential, commercial, industrial, and other buildings carry fire suppression fluids, such as water, gases, and chemicals to provide protection of life and property.

·               The piping systems in thermal power plants convey high-pressure and high temperature steam to generate electricity. Other piping systems in a power plant transport high- and low-pressure water, chemicals, low-pressure steam, and condensate.

·               Sophisticated piping systems are used to process and carry hazardous and toxic substances.

·               The piping systems in laboratories carry gases, chemicals, vapors, and other fluids that are critical for conducting research and development.

DEFINE PIPING

Piping is an assembly of pipe, fittings, valves, instruments and specialty components.

Piping is divided into three major categories:

• Large bore pipe generally includes piping which is greater than two inches in diameter.
• Small bore pipe generally includes piping which is two inches and smaller in diameter.
• Tubing is supplied in sizes up to four inches in diameter but has a wall thickness less than that of either large bore or small bore piping and is typically joined by compression fittings.

Piping system includes:

● Pipe

● Fittings (e.g. elbows, reducers, branch connections, etc.)

● Flanges, gaskets, bolting

● Valves

● Pipe supports

ASSOCIATION INVOLVED IN GENERATING CODES FOR PIPING DESIGN ENGINEERING:

● ASME

-American Society of Mechanical Engineers

● ANSI

-American National Standardization Institute

These standards give technical recommendations for designing piping system for power plants and chemical plants

● They contain formulas to calculate the minimum thickness of pipelines

● They contain formulas to calculate the extra thickness that a pipe must have when a branch is cut into it.

● They contain regulations for stress analysis

● They contain tables that give maximum allowable stress for metallic materials accepted by ANSI for pipeline construction depending on temperatures.

PIPING CODES:

ASME B31.1 - Power Piping

ASME B31.2 - Fuel Gas .Piping

ASME B31.3 - Process Piping

ASME B31.4 - Liquid Piping

ASME B31.5 - Refrigeration Piping

ASME B31.8 - Gas Distribution and Transportation

ASME B31.9 - Building Service Piping

ASME B31.11 - Slurry Piping

ASSOCIATION INVOLVED IN GENERATING MATERIAL SPECIFICATION FOR PIPING:

ASTM

-American Society for Testing Materials

● ASTM developed a collection of documents called material specifications for

standardising materials of large use in the industry. Specifications starting with “a” are for steel. Specifications starting with “b” are for non-ferrous alloys (bronze, brass, copper nickel alloys, aluminium alloys and so on). Specifications starting with “d” are for plastic material, as PVC.

● An ASTM specification does not only specify the basic chemical composition of material, but also the process through which the material is shaped into the final product.

● This is why for a given base material seamless pipe have a specification, welded pipe have another specification wrought fittings have another specification, forged fittings have another specification, large valve bodies (normally cast) have another specification

API

-American Petroleum Institute

● Rules, practices and standards for oil and gas industry are issued by this institute and followed by almost all oil and gas companies in the world.

● Among the many standards issued by the institute there is also a standard for design of pipelines: API STANDARD 5l

● Within this standard materials for oil and gas transportation pipelines are specified, with denomination API 5l

● This is a family of carbon steels almost equivalent to ASTM A53 / A106.