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Compressed Air Systems: The Secret is in the Pipe
LANL ASME B31.3 Process Piping Guide (PDF)
Piping Design Info (.xls download)
Design for Constructability
Piping Design An Introduction (PDF)
Cryogenics Primer (PDF)
Piping Designer Job Description Table
Piping Stress for the Piping Designer
Plant Layout - Pipeway Design
Process Diagrams

Thomson Delmar Learning

<<Process diagrams can be broken down into two major categories: process flow diagrams (PFDs) and process and instrument drawings (P&IDs), sometimes called piping and instrumentation drawings. A flow diagram is a simple illustration that uses process symbols to describe the primary flow path through a unit. A process flow diagram provides a quick snapshot of the operating unit. Flow diagrams include all primary equipment and flows. A technician can use this document to trace the primary flow of chemicals through the unit. Secondary or minor flows are not included. Complex control loops and instrumentation are not included. The flow diagram is used for visitor information and new employee training.>>

Piping Stress for the Piping Designer

<<Stress related technical and execution problems in the design of process plant piping are complex and must be addressed properly. There will be some Piping Designers, Stress Engineers and others who read this and say that they agree. Others may say that they do not agree. Others will just not know one way or the other. This discussion, while not covering solutions to every potential problem, is intended only to highlight some of the most common stress related factors and designer training needs.>>

Plant Layout - Pipeway Design


<<The pipeway conveys all main process lines connecting distant pieces of equipment, relief and blowdown headers, all lines leaving and entering the plant, utility lines supplying steam, air, cooling water and inert gas to the plant. Electrical and instrument cable trays are usually routed in the pipeway. Pipeways are classified by their relative elevation to grade.>>

Design for Constructability

Robert A. King, Inc.

<<Designing for constructability will be just a buzzword without the right team. The team must have the right attitude, experience and authority (or the guts to take the authority) to make things happen. It is based on the same philosophy as the "Ten Commandments of KISS Design": >>

Piping Design of Instrument Air Distribution Systems

Piping Design Central

<<Design of instrument air distribution systems is not a clear science, and there are myriad of ways to approach it. Even most experienced piping system designers take the easy way out and over design, because doing so is rarely costly and instrument air delivery systems are rarely a major cost factor in the design or installation of the plant.>>

Back to Basics: Backflow Prevention

PM Engineer

<<The goal is to assure a backflow event does not cause an unintentional reversal of flow of any substance into the potable water system that can affect water quality by means of a cross-connection. Backflow can happen because of two hydraulic conditions, backpressure and/or backsiphonage. Backpressure is a condition where a greater pressure is created on the outlet side of a piping system than from the inlet side. Pumps, thermal expansion or elevated storage tanks are different examples that can cause this condition to occur. Backsiphonage is a reversal of flow caused by a negative or sub-atmospheric pressure. Broken water mains often cause negative pressures in a potable water system by increasing demand to a point where a negative pressure can be created.>>

Flow Rates in Parallel Piping Systems

PM Engineer

<<Here's what you need to know to analyze the flow rates and head losses in parallel distribution piping systems.>>

Water Supply & Water Resources


<<EPANET models the hydraulic and water quality behavior of water distribution piping systems.>>

All You Ever Wanted to Know About DIN Piping Components (5MB+ PDF File)

Avesta Sandvik Tube AB

<<This page should answer a lot of questions many of you have dealt with in the past regarding non-ANSI piping component dimensions and weights.>>

Stainless Steel Piping Technical Data

Henderson Barwick Inc.

<<Tolerance: Pipe & Fittings Specifications, Fitting tolerances, Fabricating Tolerances, Application of Pipe Fabrication Tolerances, Fitting Pressures, Reinforcing for Vacuum Service, Stainless Steel Pipe Design Pressures>>

How to Dose Liquid Nitrogen Effectively (Liquid Nitrogen Piping)

<<Liquid nitrogen piping must have some insulation to effectively transfer the liquid nitrogen with minimal vaporization or loss. There are two types of liquid nitrogen piping: vacuum jacketed and nonvacuum jacketed. Vacuum-jacketed lines are more efficient than unjacketed lines and operate frost-free. A vacuum jacket is an annulus positioned around the inner liquid nitrogen pipe. The evacuated annulus reduces the conduction and convection heat losses to extremely low levels, creating efficient inner liquid nitrogen pipe insulation. Dynamically pumped and static vacuum are types of vacuum-jacketed lines. Static vacuum lines typically are evacuated by the manufacturer and sealed off for vacuum integrity. This vacuum eventually will degrade, resulting in increased heat losses and decreased performance over time. Dynamically pumped lines utilize a vacuum pump on the vacuum annulus. The vacuum pump must run continuously, which adds slightly to operating costs. However, vacuum integrity will improve with time and last for years. Jacketed lines can be either rigid or flexible pipes. Rigid pipes must be accurately dimensioned for proper installation into a facility, whereas flexible lines are easier to install and allow more versatile routing. By contrast, unjacketed lines typically are foam insulated and have a heat loss as much as 20 times greater than that of a jacketed line. They also have a larger outside diameter than jacketed lines. Foam-insulated lines typically lose their insulating qualities as the foam degrades over time. >>

Practical Guide to Low Temperature Refrigeration


<<Low temperature refrigeration is the range of temperatures falling below what is normally considered industrial refrigeration and above the temperatures associated with the field of cryogenics. The temperature range of this classification is from 58F to 148F (50C to 100C). This range of temperatures includes applications for food, pharmaceutical, and chemical processing. It is generally used in the petroleum and chemical industries as laboratory environmental chambers and thermal storage equipment.>>

Designing Process Piping Systems

Chemical Processing Magazine

<<The design and specification of a fiberglass-reinforced plastic (FRP) piping support system should not be a complicated proposition. Adhering to the manufacturer's design recommendations, a general understanding of the product's strengths and limitations and the application of sound piping practices helps ensure a successful installation. This article looks at some general guidelines for designing with FRP pipe.>>

Venturi Principle

Drinking Water and Backflow Prevention Magazine

<<Instructional Animation>>

Atmospheric Vacuum Breaker Operation

Drinking Water and Backflow Prevention Magazine

<<The purpose of the atmospheric vacuum breaker is to prevent a siphon from allowing a contaminant or pollutant into the potable water system. This plumbing system safety valve is considered protection from high hazard or toxic substances, and may be used for low-hazard materials as well. There are three flow conditions for the atmospheric vacuum breaker. The user obtains water by opening a valve to the potable supply allowing water to flow through the device. The user will then close the potable water supply and the device will drain. Finally, if a siphon or loss of pressure occurs in the supply piping, the inlet valve will open allowing atmosphere into the outlet piping to prevent a reversal of flow or "backsiphonage" to the potable supply.>>

Piping Flow Rate Design for Retail Refueling Facilities

Fiberglass Tank and Pipe Institute

<<Piping selection considerations for a retail motor fuel dispensing facility should include a flow rate criteria to fuel vehicles at the maximum Environmental Protection Agency (EPA) allowable of 10 gallons per minute during peak traffic periods. High-volume consumers (e. g., commuters and commercial accounts), are sensitive to the time it takes to refuel their vehicles, and they represent a significant market segment. While hydraulic flow rate calculations may be made on a site-specific basis, the purpose of this paper is to describe the major factors that reduce flow rate, how the three most common materials used to manufacture piping affect these flow rate factors, and cite flow rate "rules of thumb" for small and large retail vehicle refueling facilities based on the most commonly used piping systems.>>

Venturi Principle Atmospheric Vacuum Breaker Operation Cross-Connection Control (Backflow Prevention)

University of Southern California

<<The term backflow means any unwanted flow of used or non-potable water or substance from any domestic, industrial or institutional piping system into the pure, potable water distribution system. The direction of flow under these conditions is in the reverse direction from that intended by the system and normally assumed by the owner of the system. Backflow may be caused by numerous specific conditions; but, basically the reverse pressure gradient may be due to either a loss of pressure in the supply main called backsiphonage, or by the flow from a customer's pressurized system through an unprotected cross-connection, which is called backpressure. Thus the term backflow covers both a backsiphonage condition and a backpressure condition. A reversal of flow in a distribution main--or in the customer's system--can be created by any change of system pressure wherein the pressure at the supply point becomes lower than the pressure at the point of use. When this happens in an unprotected situation the water at the point of use will be siphoned back into the system; thus, potentially polluting or contaminating the remainder of the customer's system. It is also possible that the contaminated or polluted water could continue to backflow into the public distribution system. The point at which it is possible for a non-potable substance to come in contact with the potable drinking water system is called a cross-connection. To prevent backflow from occurring at the point of a cross-connection a backflow prevention assembly must be installed. However, it is important the backflow prevention assembly match the particular hydraulic conditions at that location and is suitable to protect against the degree of hazard present. The particular type of backflow preventer appropriate for specific needs will be discussed later. First, it is necessary to understand some basic hydraulics which govern the principles of backflow and cross-connection control.>>

Flow Through an Orifice

The Mc Nally Institute

Piping Expansion and Contraction - And How to Deal With It [DEAD LINK?]

Henning, Metz, Hartford and Associates, Inc.

<<When designing piping systems, either water or steam, thermal expansion and contraction must be anticipated. Chilled water lines will contract, heating lines will expand. Control of expansion and contraction is imperative and is typically accomplished by using anchors and expansion joints (loops).>>

Piping Expansion and Contraction - How to Design For It [DEAD LINK?]

Henning, Metz, Hartford and Associates, Inc.

<<The previous "tip of the week" spoke about forces created by pipe expansion and contraction. Now we discuss how to design to accommodate it - via application of expansion joints and anchors.>>

Pipefitting Tip of the Month, Piping Offset Calculator

A.J.'s Offset Page

<<With a great deal of help from my son we were able to put together a website that I feel can address some interesting piping offset problems. I've been a member of Pipefitters Local 208 of Denver Colorado for 20 years. I teach math and science to our first year apprentices, as well as an Advanced Offset Class for our Journeymen upgrading program. I have written a training manual that I use in the advanced class and thought it might be helpful to have a source for someone to go to when they were challenged by a difficult offset. That was the main purpose for creating this site. The site has several pages that can be used to solve just about any perpendicular, parallel, or rolling offset I can think of.>>

Cooling Tower Piping

Cooling Tower Doctor

<<A well designed piping system is essential for the proper operation of a cooling tower. Two types of systems are examined -- open and closed. In the open cooling tower, system water is open to the atmosphere as it cascades over the wet deck and falls into the cooling tower basin. The closed tower --sometimes called a "closed circuit fluid cooler"-- has the system water contained within a coil and segregated from the water that is evaporating. This is covered near the end of this chapter.>>

Overview of Plant Design

<<Plant Design (Process Plant Design, Power Plant Design, etc.) refers to the automation technologies, work practices and business rules supporting the design and engineering of process and power plants. Such plants can be built for chemical, petroleum, utility, shipbuilding, and other facilities. Plant Design is used to designate a general market area by the many vendors offer technologies to support plant design work.>>

The Injector Sparger Gas Contacting System

Explains the Basics of Injectors

<<The Injector Sparger is a simple and efficient way to scrub gasses in a confined area with limited space. These are especially suitable for scrubbing liquid ring vacuum pump exhaust. The principal is simple and well known. By using an injector to entrain the gas in a recirculating liquid stream, the gas is already dispersed by the time it reaches the tank. Proper sparger design within the tank ensures the gas is dispersed in a rotating solution to maximize contact time. An injector is a passive device similar to a venturi or eductor that uses the motive force of a liquid to generate a negative pressure at a small orifice. The motive liquid is passed through a constricted area where the injection chamber is located. The increase in velocity through the injection chamber results in a lower pressure that draw the gas into the passing liquid stream. The gas is entrained in the liquid and carried along as very fine bubbles.>>

Interconnecting Piping

The Trane Company

<<Keep these general guidelines in mind as you review the recommendations specific to suction, liquid, discharge and hot gas bypass lines>>

Process Piping Design Manual (Plastic)


Steam Condensation-Induced Waterhammer

Kirsner Consulting Engineering

<<Water hammer, according to a major steam trap manufacturer's engineering guide, is explained as follows:
"[unless] condensate is removed from low points...ripples form on the condensate surface ...until condensate so restricts steam flow that a slug of condensate is carried down the main by the steam. The slug of water travels at the speed of steam (which may be in excess of 100 mph) until some obstruction is reached...[and]...the slug of water is suddenly stopped often with disastrous results..." Although the phenomena described above will cause pipes to bang and is the mental picture most engineers associate with water hammer, it is not technically "water hammer" in a precise scientific sense-- it is steam-driven slug flow. Condensation Induced Waterhammer is a different animal. The pressure pulse generated by a Condensation Induced Waterhammer is due to the compression of water by the piston formed by the water behind it as the water is suddenly stopped or slowed. The force accelerating the water in the first place is due to a "rapid condensation event". This article explains condensation induced water hammer as it analyzes a water hammer accident that occurred in Alaska resulting in the near-death of two asbestos workers.>>

Effect of Quick Valve Closure on Piping ( Waterhammer )

Becht Engineering Company, Inc.

<<In a piping system transporting liquid, a suddenly stopped flow such as that caused by slamming shut of an inline valve creates surge pressures that are proportional to the speed of sound in the transported liquid. This surge pressure is caused by the need to change the momentum of the fluid that is flowing the pipe. These surge pressures reverberate about the operating pressure of the liquid and gradually decrease over time. The addition of surge pressure on top of the operating pressure could rupture the pipe if it exceeds the burst pressure of the pipe. On the other hand, the pipe could also be in a vacuum if magnitude of the surge pressure exceeds the operating pressure. A vacuum condition may collapse the pipe. Further, a vacuum condition is not desirable because it could cause the formation of pockets of water vapor. When these vapor pockets collapse, the columns of water on either side hammer each other, causing another pressure wave waterhammer with potentially severe overpressure conditions.>>

10 Fluid Power Lessons You Don't Learn in School

Bimba Manufacturing Company

<<Completing engineering school doesn't make you an expert - at least in fluid power. Here's some of the most common fluid power mistakes most courses never cover, and how to avoid them.>>

Finding the Best Buy in Piping

Chemical Processing on the Web

<<The piping system with the lowest installed price isn't necessarily the best value, because the piping, valves, fittings and supports may cost too much to maintain. Life-cycle costing (LLC) can determine the "real cost of ownership." Rigorous life-cycle costing involves time-value of money and probability-based considerations because no one can predict the interest rate with certainty. But those methods may take too long for quick estimates in a plant. For plants let's look at a simplified approach that can yield fast, reasonable results.>>

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