Instrumentations

What the difference instrument system block diagram and instrument cable block diagram?

Tags: instrument block diagram

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Oil And Gas Process , Instrumentations

Originally Posted by anshuman1

https://rapidshare.com/files/4590695...Relief0000.xls


2 Phase relief valve sizingg

[QUOTE=Esam;176603]

CONNECTING and INTERPRETING LIMIT SWITCHES

© Walter ********, P. Eng., 2000 May 20. walter(at)********(dot)ca

First published in Intech , January 1993 as "Limit Switches Key to Valve Reliability"

This Adobe® file is available for download.

[IMG]http://www.********.ca/limitsw/LS-1.jpg[/IMG]INTRODUCTION. There is a great variety of possible combinations for installing and connecting limit switches on valves. The number of switches depends on the particular control objective and may be influenced by redundancy considerations. The way they are connected depends on the safety and reliability requirements.
In order to clarify this discussion, diagrams like Figure 1 will be used. All signals, switch positions, etc. are shown with the valve at the center of travel. No limit switches are actuated, all are shown in their shelf position as determined by their internal springs. Imagine the valve to be like a guillotine where the stem travels upward to open the valve and downwards to close it. The diagrams show the switches connected to indicating light bulbs but the logic is identical if a DCS or other form of MMI is used.
The limit switch that is actuated when the valve is fully open is labeled ZSO. The one at the extreme opposite end is labeled ZSC.
The terminals on the electrical switches are labeled Common (C), Normally Open (NO), and Normally Closed (NC). This unfortunate choice of terminology has nothing to do with the state of the valve nor even the "normal" position of the switch. It refers to the state of the switch when nothing is pushing on it.

[IMG]http://www.********.ca/limitsw/LS-2.jpg[/IMG]SINGLE SWITCH, DIRECT APPROACH. A single limit switch at the OPEN end of the valve (ZSO), as shown in Figure 2, will tell us when the valve is fully open. It cannot tell us if the valve is ...

Optimum Settings For Automatic Controllers
the American Society of Mechanical Engineers, 1942.

First published in "Transactions of the A. S. M. E.", November 1942.

An exact facsimile on Adobe ® is available for download.
"Optimum Settings For Automatic Controllers" – is the name of one of the most important publications in the history of automation, instrumentation, and control systems. Written by Ziegler and Nichols and published in the November 1942 issue of the Transactions of the American Society of Mechanical Engineers, it gave the "hit and miss" art of tuning controllers a practical basis. Ziegler and Nichols developed and published tuning rules for pneumatic PID controllers while working in Rochester, NY for Taylor Instruments, now a part of ABB. Although developed for pneumatic controllers, their rules are still widely used as a comparison for other methods. When Nichols died in April 1997, at age 82, and Ziegler not long after on December 9, at age 88, a chapter in industrial automatic control came to an end.
The ASME graciously granted permission for me to reproduce "Optimum Settings for Automatic Controllers", © 1942, on my website, walter(at)********(dot)ca. To generate this reproduction, a photocopy of the printed original has been scanned, run through an optical character recognition (OCR) program, formatted in MS Word, and edited to duplicate the original as closely as possible. The diagrams were scanned and embedded in the Word file in .jpg format. Finally, this MS Word "forgery" was converted into .html and .pdf formats.

I thank the ASME for allowing this important work to be made so freely available. The society can be reached at www.asme.org. I would also like to thank my daughter, Mika ********, for her patience with the OCR work.

Optimum Settings

...

[QUOTE=Esam;176596]CONTROLLING FIRED HEATERS © Walter ********, P. Eng., 2000 May 20. walter(at)********(dot)ca

First published in Hydrocarbon Processing , April 1997.

This Adobe® file is available for download.


[IMG]http://www.********.ca/ce5_fh/5-1.jpg[/IMG]INTRODUCTION. The purpose of a fired heater is very simple: To add heat to a process fluid. Its representation on a process flow diagram is also very simple. But, of course, fired heaters are among the most complex pieces of process control equipment. Each furnace is, after all, at least two pieces of equipment in one. Firstly, it is a special variant of the shell and tube heat exchanger since its purpose is to exchange heat. Secondly, it is a chemical reactor in which fuel and air undergo extremely exothermic reactions to produce the required heat.

In previous articles of this series^{1, 2, 3, 4}, the process aspects of controlling a piece of equipment were presented before dealing with protection and safety. This time the topics will be reversed: In the case of fired heaters, it must be safety first!
SAFETY. If fired heaters had not been invented and were being proposed for the first time, I would probably say, "You've got to be kidding. That thing will blow up in your face the first time you throw a match in it." However, at least a half a billion gas fired heaters are in service around the world (according to the American Gas Association). Most of them are operated by people with no technical experience whatsoever; few heaters blow up. Still, the average domestic water heater is not in the same league as a hydrogen reformer furnace. The fact that accidents and disasters are as few as they are, is due to the long experience the human race has in dealing with fire. A million years, I'm told. For the last century, this experience has been embodied in various codes and standards that ...

[QUOTE=Esam;176591]

CONTROLLING STEAM HEATERS

© Walter ********, P. Eng., 2000 May 20. walter(at)********(dot)ca

First published in Hydrocarbon Processing , November 1996.

This Adobe® file is available for download.


INTRODUCTION. Steam Heaters are simply heat exchangers in which one of the media is steam being condensed while the other is a process fluid being heated. In doing this, there is a phase change which puts special demands on the process control system. It is difficult to generalize about the various options for control. Special system requirements often put unexpected constraints on the process. Even the orientation of the exchanger can have peculiar and unexpected results.
[IMG]http://www.********.ca/ce4_sh/4-1.jpg[/IMG]A SIMPLE STEAM SPACE HEATER. Figure 4-1 shows a steam heater such as those used to heat a warehouse. This simple example demonstrates many of the characteristics of steam heaters of all sizes and applications. Steam enters the heater at the top. As the moving air draws away the heat, the steam condenses. The condensate flows down the tubes, through the steam trap, and into the condensate drain header.
The function of the steam trap is to prevent steam from blowing through into the condensate system. It is the one essential part of any steam heater and will receive further attention later. For now it is sufficient to say only that it passes condensate and blocks steam.
This system tends to be rather self-regulating. The moving air rises to some temperature approaching that of the steam and draws away as much heat as it can. Colder air will draw more heat, and warm air will draw less. The steam trap is essentially a level controller with a set point of zero.
This arrangement can be compared to a shell and tube exchanger where the room itself ...

please help me to design a RC type slow operating relay with a delay time of 3 sec.
please suggest the values of R and C for getting 3sec delay

Hi All,

I need information on the safety requirements for drillers cabins.

IE: Purge pressureization requirements
Gas Monitoring
API/Class recommendations.
Does the Cabin Exterior need to meet A-60 bulkhead requirements
Entry Door Requirements
Glass Enclosure Requirements.

Thanks in advance for any help

Professional Training Course in Pipe Stress Analysis
Course Objective
• To apply the piping system stress analysis requirements of International Codes.
• To understand how to use piping analysis software to meet these requirements.
• To understand specific illustrations based on the Computer Aided Stress Analysis.

Course Overview
• Role of the stress analyst.
• When to perform stress analysis.
• Piping Code History.
• Stress theory; evaluating stresses on piping & knowing which ones matter.
• Load types, Failure criteria; primary & fatigue failures.
• Code equations, Stress Intensification (SIFs).
• Overview of Computer Aided Stress Analysis functions and how to use the program.
• Detailed, important modelling issues – bends, reducers, valves, rigid elements, control parameters, non-linearity of restraints, connecting nodes, built-in databases and assorted modelling issues.
• The mathematics behind Computer Aided Stress Analysis – Stiffness matrices and related issues.
• Practical examples using Computer Aided Stress Analysis; input, analysis & redesign.
• Theory – Designing for sustained loads; support configuration issues, spring hanger design, optimization of sustained loads.
• Practical example.
• Theory – Designing for expansion loads; flexibility.
• Practical Examples.
• Detailed problem solving of a complex model, including:
• Imposed thermal displacements.
• Expansion joint modelling & evaluation.
• Structural steel modelling.
• Spring hanger design.
• Combining steel with piping.
• Verification of API 610 pump loads.
• Local vessel flexibilities using WRC 297.
• Including vessel modelling.
• Evaluation of local vessel stresses according to WRC 107.
...

Tags: pipe stress analysis

Categories

Engineering Codes, Standards & Certifications , General & petroleum News , Oil And Gas Process , Instrumentations , Miscellaneous

Originally Posted by essjayjoe

Currently the only free version (------ed version) available on internet is Instrucalc 5.1 Plus. The download link to that is available in the forum if you search for Instrucalc. I have downloaded it and validated its calculation results against INTOOLS calculation module, Flowel 4, FirstVue, ValvSpeQ etc.

I searched high and low in the internet for a free (----ed version) version of Instrucalc 7.1. It is not available. There are several forums who claim to provide it. But they are all out to swindle you as I have realized painfully.
I do not know if Instrucalc 5.1 Plus works in Windows 7. I am still sticking to Windows XP. Most of these software's are compatible with XP.