Corporate Communications

Mach II CDS Version

1.08

Corporate Communications

MACH II Digital Engineer - User Guide

Relief Device Calculation Software

Two-Phase Version

ã 2000, 2001, 2003 Digital Solutions Technology, Inc

3605 Alden Street

Indian Trail, NC 28079

Phone 704-893-0294• Fax 704-882-5729 http://www.digitalsolutions.org/

Disclaimer

DISCLAIMER OF WARRANTIES. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, DIGITAL SOLUTIONS, INC. AND ITS SUPPLIERS PROVIDE TO YOU THE COMPONENTS AS IS AND WITHOUT ANY SUPPORT SERVICES; AND DIGITAL SOLUTIONS, INC. AND ITS SUPPLIERS HEREBY DISCLAIM WITH RESPECT TO THE COMPONENTS ALL WARRANTIES AND CONDITIONS, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, ANY (IF ANY) WARRANTIES OR CONDITIONS OF OR RELATED TO: TITLE, NON-INFRINGEMENT, MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, LACK OF VIRUSES, ACCURACY OR COMPLETENESS OF RESPONSES, RESULTS, LACK OF NEGLIGENCE OR LACK OF WORKMANLIKE EFFORT, QUIET ENJOYMENT, QUIET POSSESSION, AND CORRESPONDENCE TO DESCRIPTION. THE ENTIRE RISK ARISING OUT OF USE OR PERFORMANCE OF THE COMPONENTS AND ANY SUPPORT SERVICES REMAINS WITH YOU.

EXCLUSION OF INCIDENTAL, CONSEQUENTIAL AND CERTAIN OTHER DAMAGES. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL DIGITAL SOLUTIONS, INC. OR ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL, INDIRECT, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING, BUT NOT LIMITED TO, DAMAGES FOR: LOSS OF PROFITS, LOSS OF CONFIDENTIAL OR OTHER INFORMATION, BUSINESS INTERRUPTION, PERSONAL INJURY, LOSS OF PRIVACY, FAILURE TO MEET ANY DUTY (INCLUDING OF GOOD FAITH OR OF REASONABLE CARE), NEGLIGENCE, AND ANY OTHER PECUNIARY OR OTHER LOSS WHATSOEVER) ARISING OUT OF OR IN ANY WAY RELATED TO THE USE OF OR INABILITY TO USE THE COMPONENTS OR THE SUPPORT SERVICES, OR THE PROVISION OF OR FAILURE TO PROVIDE SUPPORT SERVICES, OR OTHERWISE UNDER OR IN CONNECTION WITH ANY PROVISION OF THIS SUPPLEMENTAL EULA, EVEN IF DIGITAL SOLUTIONS, INC. OR ANY SUPPLIER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

LIMITATION OF LIABILITY AND REMEDIES. NOTWITHSTANDING ANY DAMAGES THAT YOU MIGHT INCUR FOR ANY REASON WHATSOEVER (INCLUDING, WITHOUT LIMITATION, ALL DAMAGES REFERENCED ABOVE AND ALL DIRECT OR GENERAL DAMAGES), THE ENTIRE LIABILITY OF DIGITAL SOLUTIONS, INC. AND ANY OF ITS SUPPLIERS UNDER ANY PROVISION OF THIS SUPPLEMENTAL EULA AND YOUR EXCLUSIVE REMEDY FOR ALL OF THE FOREGOING SHALL BE LIMITED TO THE GREATER OF THE AMOUNT ACTUALLY PAID BY YOU FOR THE COMPONENTS OR U.S.$5.00. THE FOREGOING LIMITATIONS, EXCLUSIONS AND DISCLAIMERS SHALL APPLY TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, EVEN IF ANY REMEDY FAILS ITS ESSENTIAL PURPOSE

This document is intended for use by customers of Digital Solutions, Inc. It was developed and published by:

Digital Solutions

Department of Information Management

Enterprise Processes & Data Architecture

3605 Alden Street, Indian Trail, NC 28212

Telephone: 704-893-0294 • Fax 704-882-5729

http://www.digitalsolutions.org

This document contains information that is proprietary to Digital Solutions Corporation. The content of this document is privileged, confidential and exempt from disclosure under applicable laws. No part of this document may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopied, recorded, or otherwise, without prior written consent from Digital Solutions Corporation.

Printed in the United States of America.

If you have any comments or questions about technical aspects of this document, including formulae and calculations, please contact:

Edward Kitchen - President & Chief Engineer

If you have any comments or questions about database integration or infrastructure options, please contact:

Thomas E. Coughlan - CTIO

Revision History

Version / Description or Purpose of Change / Owner(s)
Number / Date
1.03 / 8/12/01 / Release 1.03 Documentation. / T. Coughlan, E. Kitchen
1.04 / 10/22/01 / Release 1.04 Documentation.
Added 2-Phase documentation developed by E. Kitchen. Enhanced layout to make it more readable. / E. Kitchen, T. Coughlan
1.05 / 11/01/01 / Updated graphic images, added tool bar f functionality. / T. Coughlan
1.06 / 12/05/01 / Added text for Search Engine. Changed "Demo" to "Reader" / T. Coughlan/ E. Kitchen
1.07 / 4/28/02 / Added section on HEM and OMEGA. Replaced *.bmp images with *.GIF images to minimize file size, changed to 11 point Arial font. / T. Coughlan/E. Kitchen
1.08 / 7/15/03 / Replaced formulae. Updated GUI screen shots. Changed address and copyright year. Formatted formulas and variables into tables for clarity. / T. Coughlan/E.Kitchen

This documentation and the software described herein are copyrighted, with all rights reserved. Under copyright laws, this documentation and software may not be copied in whole or in part without the written consent of Digital Solutions, Inc., Inc. except in the normal use of the software or to make a backup copy as specified in the license agreement.

Trademarks:

“Mach II CDS Ô” is a trademark of Digital Solutions, Inc.

“Mach II Digital Engineer Ô” is a trademark of Digital Solutions, Inc.

“Mach II CDS-Reader Ô” is a trademark of Digital Solutions, Inc.

All trademarks and registered trademarks are acknowledged throughout this document.

Who We Are 2

About the Software 2

Process Safety Management (PSM) 2

Relief Valves 3

Program Instructions 4

MACH II CDS 5

Supporting Documents 5

Identification Section 6

Two-Phase Section 10

Performing a Two-Phase Flow Test 10

Summary of Two-Phase Test Calculations Performed: 11

Variables used in the Two-Phase Test: 12

Completing System Data Requirements 13

Operating Data 14

Basic Data 15

Two-Phase Homogenous Equilibrium Model (HEM) 15

Performing a HEM Two-Phase Flow Calculation for the Nozzle 16

Equation 1 (At relieving pressure P2): 16

Equation 2 (At estimated choke pressure): 16

Coupling Equation (for Gmax): 17

Omega Method 18

At relieving pressure P2: 18

At set/choke pressure P1 18

Coupling Equation 20

Actual Required Orifice Size 22

Piping & Pressure Drop 23

Inlet and Outlet Piping 23

Omega Method Piping 25

Performing an Omega Method Calculation for Piping 26

Variables used in the Omega Piping: 27

Back-Pressure Effects based on the Omega Method 28

Sonic Flow 28

Sub-sonic Flow 29

HEM Method Piping 30

Simple Three-point Specific Volume 31

Complex Three-point Viscosity Correlation 31

Complex Three-point Viscosity Correlation 32

Complex Three-point Specific Volume Model with Mass Fraction Correlation 33

Liquid Density Correlation 34

Specific Volume Correlation 35

Specification and Maintenance 36

Report Generator (Production) 37

Tools 39

TP- HEM Nozzle Integration 40

TP- HEM Piping Integration 42

TP-Linear Regression 43

Regression Options: 44

Regression Modeling Options: 44

Linear Regression – Quick Tutorial 44

Linear Regression – Quick Tutorial 45

Polynomial Regression – Quick Tutorial 45

Exponential Regression – Quick Tutorial 46

MACH II CDS User Guide

Chapter

Introduction

Who We Are

elcome to Digital Solutions Technology, Inc. and its subsidiary Safety Relief Device Documentation Services. We can be found at www.digitalsolutions.org. We ask that you visit us often to take advantage of the many services and valuable links offered from our web site as well as staying abreast of new products and updates.

The Reader version of our program, Mach II CDS-Reader™, will give potential users an opportunity to explore its powerful calculation engine and give a feel for its capabilities and use prior to purchasing a full site license. The Reader is absolutely free and gives everyone the ability to read, view, and print .cds files created using the Mach II-CDS application program.

About the Software

This software has been designed based on the requirements as set forth in OSHA 29 CFR 1910.119a, which can be accessed from the company’s web site under "Relief Design Information -> Industry Standards" link www.digitalsolutions.org. It simply states that relief system design and design-based calculations must be compiled and maintained for all processes involving highly hazardous chemicals.

A list of those highly hazardous chemicals can also be accessed from within the OSHA link: http://www.osha-slc.gov/OshStd_toc/OSHA_Std_toc_1910_SUBPART_H.html

However, some companies have mandated in their own standards that all processes will adhere to this regulation by a self appointed deadline. In their minds, they can realize the prognosis and don't want to wait until OSHA applies this law across the board. If a vessel has a rupture or explosion it doesn't matter what fluid is inside the vessel, its impact will still cause damage to equipment, piping and possibly to personnel.

Process Safety Management (PSM)

The buzzword in the business is Process Safety Management and the acronym is PSM. You can read about the scope of PSM from the linked page within OSHA. In general, it is concerned with effective management of every aspect of the process from personnel, equipment, piping, drawings, procedures, technology, and all associated issues that can affect the safety and integrity of the process. These regulations are a legal requirement that is mandated by the government to protect the safety of personnel in the work place

Relief Valves

The safety relief device, which includes relief valves, rupture discs, and conservation vents, are the last line of defense in protecting the process equipment, piping, and personnel from possible explosions within the plant site.

Pressure relief valves are designed to provide protection from over-pressure in steam, gas, air and liquid lines. Relief valves and back pressure regulators are the same device, only differing in application. The pressure relief valve "lets off steam" when safe pressures are exceeded, then closes again when pressure drops to a preset level. A back pressure regulator maintains upstream pressure at the desired setting by opening to allow excess upstream pressure to flow downstream.
A pressure relief valve is a self-operating valve that is installed in a process system to protect against over pressurization of the system. Relief valves are designed to continuously regulate fluid flow, and to keep pressure from exceeding a preset value. There are a wide variety of valve designs, but most resemble diaphragm valves, globe valves, or swing check valves. With many of these designs, a helical or hydraulic pressure spring is used to maintain constant force acting on the backside of the valve disk or diaphragm, causing the valve to be normally closed. When the force exerted by the process stream (i.e. fluid pressure) on the valve disk is greater than the constant force exerted by the spring, the valve opens allowing process fluid to exit the valve until the fluid pressure falls below the preset value. These valves can be preset to a specific relief pressure or they may be adjustable.
The flow transfer and control category covers a wide spectrum of products designed to facilitate, control, maintain, meter, or read the flow of material through hoses, pipes or tubing. The material in question can be liquid, gaseous, or semi-solid (colloids and slurries). The following families fall within this category: valves, valve actuators and positioners, dispensing valves, pumps, flow sensing, level sensing, density and specific gravity sensing, viscosity sensing, and miscellaneous related products.
Valves are apparatus designed to maintain, restrict, or meter the flow of materials through pipes, hoses, tubing or entire systems. They generally function by allowing flow while in their open position, and restricting flow when closed. The valve family is broken down into product areas based on the mechanism that is used to restrict flow. The following are the main valve product area: ball valves, butterfly valves, check valves, diaphragm valves, gate or knife valves, globe valves, needle valves, pinch valves (for both industrial and medical applications), plug valves, control valves (1/4 turn - isolation and multi-turn, throttling), pressure relief valves, and AC and DC solenoid valves.

Murphy's law dictates that if such an event can happen, it eventually will happen with time being the only criterion. This observation also dictates that these facilities must perform Process Hazard Analysis/Reviews (Hazops) to identify potential hazards within each process and to document a course of action to protect against the potential of a catastrophic failure. The relief devices serve as a final course of action against a catastrophic event.

Program Instructions

Mach II CDS-Reader™ is a crippled version in that it only reads files with a *.cds extension created by the full application program. The Mach II program will handle liquid, gas, vapor, steam and two-phase release scenarios.

The Mach II Digital Engineer™ program will calculate the required capacity of each scenario not already input by the user, and will then calculate the required and standard orifice size and standard relief capacity. The program will then select the worst-case scenario, largest required orifice, as the basis for the design of the relief system to include the associated piping. The program also has a built-in piping program where the user can choose the number and type of fitting for both inlet and outlet piping. Mach II CDS™ then calculates the piping resistance and pressure drop for this piping arrangement. Mach II CDS™ is intuitive to use and the results are produced instantaneously by just clicking on the Production tab after all input data has been entered

The results are given in summary and detail formats. This will enable a user to go directly to the end of the document to examine the bottom-line results in a summary table.

MACH II CDS

Supporting Documents

The Two-Phase User Guide is preceded by the following documentation:

· The Single-Phase User Guide is available separately for users interested in the single-phase process.

· Installation and Common Features User Guide which outlines the features in Mach II CDS™ common to the single and Two-Phase components.

· Calculation and Formulae Guide provides engineers with technical formulas, references and mathematical routines that guide the Mach II calculation process.

In addition to the above guides, the Infrastructure Documentation and Technical Installation Guides are available to systems and technical personnel planning for or installing the Mach II CDS™ system.

Where applicable, references are made to these supporting documents at critical junctions from this manual.

Identification Section

In this section, the user enters identification data about:

· The company performing calculations

· Client

· Calculating Engineer

· Documentation Checker