JS Pressure Safety Valve Final

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2013 Aspen Technology, Inc. AspenTech, aspenONE, the Aspen leaf logo, the aspenONE logo, and OPTIMIZE are trademarks of Aspen Technology, Inc. All rights reserved. 11-3842-0713

Jump Start: Pressure Safety Valve Sizingin Aspen HYSYS

A Brief Tutorial (and supplement to training and online documentation)

Nicholas Brownrigg, Product Marketing, Aspen Technology, Inc.

Wilfried Mofor, Product Management, Aspen Technology, Inc.


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Jump Start: Pressure Safety Valve Sizing in Aspen HYSYS

Contents

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Adding a Pressure Relieving Device to a HYSYS Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Designing and Sizing a Pressure Safety Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Valve Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Scenario Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Sizing Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Custom Orifice Sizing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Multiple Valve Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Line Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Equivalent Length Calculation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Documentation Builder. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Importing Valve Sizing and Scenarios within Aspen Flare System Analyzer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Relief Valve Sizing and Dynamic Simulation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25


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IntroductionWhen designing a chemical process and its equipment, safety is of substantial concern. All possible strategies should be

considered to eliminate the risk of accident and injury when implementing a process design.

One safety concern that occurs frequently in a plant is the over-pressurization of equipment or piping. In order to prevent

dangerous bursts, explosions, and fires, pressure relief valves are designed and installed to bleed out excess liquid or vapor

causing pressure build-up.

Process conditions vary vastly at each location of a pressure relief valve. Because of this, and the strict regulation of safety

equipment, completing a design of a pressure relief valve by hand can be a time consuming and laborious exercise. To

solve this problem, Aspen HYSYS V8.3 has a pressure safety valve sizing feature, which uses data from a process

simulation to help automate PSV calculations.

Aspen HYSYS uses common valve design standards, most notably API 520, 521, to determine pressure relief valve sizing

information and values. 25 common overpressure scenarios are included in the program and can be analyzed and sized for.

Aspen HYSYS also features a line sizing functionality, allowing the user to quickly choose the schedule and diameter

according to pressure drop and fluid velocity constraints for piping entering and leaving the pressure safety valve. Line

sizing is completed in Aspen HYSYS without having to perform any fluid flow computations.

The documentation builder pulls valve sizing and process variable information directly from simulation to automatically

complete required forms normally requiring manual incorporation.

This Jump Start guide will walk the reader through the process of using pressure relief valve features in Aspen HYSYS

towards designing a pressure relief valve. AspenTech recommends that a range of other resources be called upon in

conjunction with this document to give the user a comprehensive view of how to use Aspen HYSYS. These may include:

AspenTech support website (support.aspentech.com) contains information on the use of AspenTech products and

provides answers to frequently asked questions.

AspenTech courseware available in on-line and in-person versions

AspenTech business consultants

This document will show how to size pressure safety valves using Aspen HYSYS V8.3. It assumes that the user has Aspen

HYSYS V8.3 or higher installed on her or his computer and a functional process design completed.
http://support.aspentech.com/http://support.aspentech.com/


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Adding a Pressure Relieving Device to a HYSYS SimulationIn order to add a pressure safety valve to a HYSYS process flowsheet, the user must enter the Safety Analysis

environment. This environment provides a setting for relief scenario setup and PSV sizing and documentation.

After designing a process in Aspen HYSYS and converging the simulation, click on Pressure Relief in the Home ribbon of

the HYSYS Simulation environment to enter the Safety Analysis environment. Alternatively, the Safety Analysis button,

located on the bottom left of the Aspen HYSYS program, can be used. Both options are shown below in Figures 1 and 2.

Figure 1. Pressure Relief Button on Home Tab

Figure 2. Safety Analysis Option in Aspen HYSYS

After opening the Safety Analysis viewing window, select the Unit Operations option in the navigation pane on the left of

the screen. This will display all the unit operations and subflowsheets present in the simulation for which a pressure safety

valve can be designed. Also, in the navigation pane is the Unattached Streams option, in which floating/dangling

streams with no connections to process models are located (Figure 3).

Figure 3. Location of Unit Operations and Unattached Streams Menus in Safety Analysis Panel

To add a PSV to a simulation, click the Add PSV option on the ribbon in the Safety Analysis environment (Figure 4). This

switches the cursor into attach mode. Hover over the stream or unit operation on which a PSV is necessary. When the

cursor arrow changes and displays a white box, click to attach a relief valve.


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Figure 4. Add PSV Option in Safety Analysis Environment

A PSV can also be added using the navigation pane. Open the Unit Operations or Unattached Streams node and right

click the desired block or stream. Scroll to highlight the Create PSV option. When prompted, select which stream the

valve should be located on. An example of this PSV addition method is shown in Figure 5.

Figure 5. Adding a Pressure Safety Valve and Selecting the Appropriate Stream

A PSV will be placed on the flowsheet in the Safety Analysis environment after following one of the methods described

above. Figure 6 shows an example flowsheet with a PSV attached to a stream connected to a process unit, while Figure 7

shows a PSV attached to a single stream unaffiliated with any unit operations.


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Figure 6. Process Stream with PSV

Figure 7. Unattached Stream with PSV

Designing and Sizing a Pressure Safety ValveAdding a pressure safety valve to a unit operation in a simulation allows the user to open tabs in which the pressure safety

valve can be designed and sized to meet relief specifications and requirements.

Valve Design

Double-clicking on a pressure safety valve on the flowsheet opens the Valve Design tab, shown in Figure 8. In this tab,general valve design details are input.


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Figure 8. Valve Design Tab

First, choose the appropriate options from the dropdown menus to define the valve material of construction, valve type,

and valve discharge. Next, the valve design temperature and the set pressure at which the valve opens should be specified.

After doing so, set a value for the superimposed backpressure present in the valve, according to design calculations.

If the valve will have a rupture disk, ensure that the Rupture Disk Factor entry has a value of 0.9. If there will be no rupture

disk, this value should be 1.

Click the Create Scenario button above the scenario list table to evaluate multiple relief scenarios for which a relief valve

is necessary and obtain PSV sizing for each scenario. The Create Scenario button and a populated scenario list table are

shown in Figure 9.

Figure 9. Creating a Scenario in the Valve Design Tab


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After clicking the Create Scenario option, a new pressure relief scenario is created in the scenario list table. To open the

Scenario Setup tab and obtain a relief load and PSV size, simply click the emergency scenario name on the scenario list

table.

Another method of opening the Scenario Setup tab is to return to the Unit Operations tree in the navigation pane (Figure

10). Click the PSV option under its corresponding unit block to open the scenario listing. Then, choose the applicablescenario to open the Scenario Setup tab.

Figure 10. Opening Scenario Setup Tab from Unit Operations Tree

Scenario Setup

After clicking on a scenario or choosing a scenario from the navigation pane, the Scenario Setup tab, shown in Figure 11,

appears.

Figure 11. Scenario Setup Tab


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Included in Aspen HYSYS are four different design codes. The four codes are API 520 & 521, ASME VIII, PD 5500, and EN

13445. Select the pertinent design code from the dropdown menu before continuing.

Enter the relieving temperature necessary for the given relief scenario being analyzed before proceeding to calculation of

the relieving pressure. Click the Calc button next to the Relieving Pressure box to bring up the window shown in Figure

12.

Figure 12. Relieving Pressure Calculation Window

In the Relieving Pressure Calculation window, input the allowable overpressure percentage, which determines the amount

of pressure that can build up beyond the set pressure before the valve opens. After finishing, verify that the relieving

pressure is correct, and select OK to continue.

Similar to the Relieving Pressure Calculation window, clicking Calc next to the Total Backpressure box opens the

window displayed in Figure 13. Set the parameters describing the backpressure and click OK to continue.

Figure 13. Backpressure Calculation Window


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Enter the valve discharge coefficient if the value differs from the default value of 0.9750. Then, choose the failure scenario

type under the Relief Load grouping. To obtain a relieving flow load, a manually calculated value can be entered or the

reference flow value from the HYSYS process stream that the PSV is attached to can be used. Additionally, if a relief

scenario that is highlighted in blue on the scenario list (Fire, Control Valve Failure, Exchanger Tube Rupture, Fan Failure, or

Reflux Failure) is chosen, the relief load can be calculated in Aspen HYSYS by selecting the Calculated radio button and

by providing more parameters surrounding the scenario where prompted. Figure 14 shows the scenarios available in the

Scenario Type list, while Figure 15 shows a sample relieving load calculation for a Fire relief scenario..

Figure 14. Relief Load Scenarios Available

Figure 15. Sample Calculation of Relieving Flow for Fire Relief Scenario


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When all scenario input is complete, Aspen HYSYS will display valve sizing results in the table on the right-hand side of

the tab, detailed in the next section of this guide.

Sizing Results

After finishing parameter input in the Valve Design and Scenario Setup tabs, the valve sizing results will be displayed in

the Valve Results table (Figure 16), located within the Scenario Setup tab.

Figure 16. Valve Results Table inside Scenario Setup Tab

The results table includes important information required to choose an appropriate safety valve for installation. The

calculated orifice area and valve coefficient are given. Also provided is the level of noise, in decibels, that the valve willmake at a given height when in use.

Using the calculated orifice area, the user is prompted to select an actual standardized orifice size for the valve from a

dropdown menu in the Valve Results table (Figure 17). It is recommended to pick the next largest orifice size from the

calculated orifice size in order to ensure correct valve operation. For example, in Figure 17, because the calculated orifice is

8.442 cm2, the user should select the 11.858 cm2 option from the dropdown menu. After selecting an orifice size, the

valves rated capacity and capacity used is displayed, along with orifice design information and in and out flange sizing.


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Figure 17. Selected Orifice Dropdown Box with Options

If the scenario being analyzed is the basis case for which the valve is sized, select the Sizing Case box, next to theScenario Name input box. Then, return to the Valve Design tab to proceed to line sizing for the relief valve.

Custom Orifice Sizing

The selectable orifice sizes that come standard in Aspen HYSYS are based off of API 526 standards. If different orifice

sizes are necessary, custom orifice sizes can be specified by going to the Customize tab on the ribbon in the Safety

Analysis environment and clicking the Custom Orifices option as shown in Figure 18 below.

Figure 18. Accessing Custom Orifice Editing

Clicking the Custom Orifices option opens a window in which the selectable orifice areas and displayed names can be

updated to fit the users needs. To edit an orifice, check the box under the Add Custom column and type the appropriate

name and orifice area. The Custom Orifices window is shown in Figure 19.


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Figure 19. Custom Orifice Area Editing

Multiple Valve Sizing

If the computed relief load is too large to be relieved using just one pressure safety valve, it is necessary to pass the

relieving flow through multiple pressure valves. Successful sizing of multiple valves for a stream in Aspen HYSYS requires

returning to the Simulation environment and using a tee splitter block to divide the relief load stream into multiple streams

equal to the number of relief valves necessary. Figure 20 shows an example flowsheet with a tee splitter for the Vap

Outlet stream in the process split into two separate relief load streams.

Figure 20. Tee Block to Size Multiple Valves for Vap Outlet Stream

Double-click the stream entering the tee block, and define its conditions, properties, and composition by selecting the

Define from Other Stream button that appears in the material stream window (Figure 21), and then select the

appropriate stream to be relieved by multiple valves.


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Figure 21. Define from Other Stream Option in Relief Load Material Stream Window

Return to the flowsheet, double-click the tee block, go to the parameters section, and input the appropriate flow ratio for

each stream exiting the splitter to define how the flow of the relief load will be split amongst the valves (Figure 22).

Figure 22. Defining the Flow Ratio for the Relief Load Splitter

After setting up the tee block to split the relief load flow, return to the Safety Analysis environment. Add a PSV to each

stream exiting the tee block, such that the streams exiting the tee block look similar to the ones shown in the flowsheet in

Figure 23.


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Figure 23. Safety Analysis Environment Flowsheet with PSVs Attached

Proceed to size the safety valves as previously described in this guide, except use a 16% allowable overpressure when

determining the relieving pressure for the valve with the highest flow rate and an 11% allowable overpressure for all

subsequent valves with lesser flowrates.

Line SizingReturn to the Valve Design tab after creating and sizing all scenarios requiring a pressure relief valve. The scenario list in

the Valve Design tab will now be populated with sizing information regarding each scenario. If not done before, use the

Sizing Case check box on the scenario list, Figure 24, to choose which failure scenario the valve will be sized for.

Figure 24. Scenario List Table Inside Valve Design Tab with Selected Sizing Case Scenario

Selecting a sizing case enables the Line Sizing tab for selection. Click the Line Sizing tab, as shown in Figure 25, to begin

line sizing for the pressure safety valve.

Figure 25. Location of Line Sizing Tab

Under the line sizing tab, the piping in and out of the pressure safety valve can be chosen. If the pipe size chosen by the

user is too small to accommodate relief flow or too large such that the pressure gradient will not allow for relief flow,

Aspen HYSYS will alert the user using the bar on the bottom of the tab so that an incorrect design is not selected. If the

bar is green, it means that an appropriate line size has been selected, while yellow means there is either a fluid pressure

or velocity constraint being violated by the chosen line sizing.


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Specify the nominal diameter and schedule of the piping for the in and out lines. Aspen HYSYS will use the rated flowrate

through the pipes to calculate the change in pressure and velocity. (For most cases, rated flowrate is used and the

design/required flow through the PSV is used for liquid or fire scenarios. The user has the ability to change this value if the

HYSYS defaults do not match.) These results are displayed in the Line Sizing Results table. Figure 26 shows the Line

Sizing tab layout.

Figure 26. Layout of Line Sizing Tab

The pressure drop and fluid velocity constraints for line sizing are preset according to API standards. To change these

constraints, click the Constraint Setting button in the Line Sizing tab. The following window will open, allowing the user to

change the line sizing constraints as desired.

Figure 27. Line Sizing Constraint Settings


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Equivalent Length Calculation

The equivalent length of the piping can be entered in the appropriate field inside the Line Sizing tab. There is also a

feature in Aspen HYSYS that calculates the equivalent length of the piping. To access this feature, check the Calculate

Equivalent Length box. This will bring up a menu within the Line Sizing tab in which the quantity of the present pipe

fittings can be specified along with their L/D ratios. After entering the number of fittings, a calculated equivalent lengthwill appear, as shown in Figure 28.

Figure 28. Calculate Equivalent Length Function

Documentation BuilderAfter completing all design and sizing for a pressure relief valve, filling out documentation is required in order to meet

regulated safety compliances, and for valve vendor submission. In order to reduce tedium in this area, Aspen HYSYS has a

documentation builder function inside the Safety Analysis environment (Figure 29), which pulls data from the simulation

and valve sizing, to automatically complete required forms. To access the customizable documentation builder, click the

Documentation Builder option from the home ribbon. Similarly, to obtain a built-in HYSYS report, choose the desired

option, located to the left of the Documentation Builder option.


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Figure 29. Documentation Builder and HYSYS Reports Options While in Safety Analysis Environment

The Built-in HYSYS Reports feature provides instant documentation of valve parameters and relieving conditions gathered

directly from the safety analysis relief scenario being analyzed. Built-in HYSYS reports are not editable; the

Documentation Builder should be used for more in-depth, editable reporting. Shown in Figure 30 is an example HYSYS

Calculation Sheet.

Figure 30. Example Built-in HYSYS PSV Calculation Report

Clicking the Documentation Builder option initiates Microsoft Access, which houses the customizable forms to be

completed after designing and sizing a pressure relief valve. From the documentation builders home screen, shown below

in Figure 31, a list of relief devices sized in Aspen HYSYS can be edited or viewed. Additionally, process data sheets,

mechanical data sheets, calculation summary sheets, or relief load summary sheets can be constructed. Information from

the sheets can be exported to Microsoft Excel by selecting any of the respective Export options.


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Figure 31. Microsoft Access Documentation Builder Selection Screen

Choosing the edit option for any of the forms from the documentation builder brings up a screen allowing the user to

change the information that will appear in the final, viewable report. Many entries are already populated by values pulled

directly from Aspen HYSYS. These are denoted in grey. The spaces in white require user input to be completed. A sample

edit page for a mechanical data sheet is shown in the following figure.

Figure 32. Edit Page for Mechanical Data Sheet


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After entering the pertinent information for a datasheet on its edit page, return to the documentation builder home screen,

then select View to see a copy of the finalized version of the document chosen. After opening a document using the

View option, it can then be saved electronically or printed. Figure 33 shows a completed sample mechanical data sheet,

given the input information from the edit page shown in Figure 32.

Figure 33. Completed Example Mechanical Data Sheet

Completing documentation using the documentation builder in Aspen HYSYS reduces the time needed to complete safety

valve paperwork to submit to regulatory agencies and valve vendors.


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Importing Valve Sizing and Scenarios within Aspen Flare

System AnalyzerWhen using Aspen HYSYS V8.4 or higher, relief valve sizing and scenarios can be imported within Aspen Flare System

Analyzer V8.4 or higher in order to assist in the designing and rating of a processs flare system.

To successfully import relief valve sizing results, the Aspen HYSYS file must first be saved as either a HYSYS Compound

File (.hscz), or as a HYSYS Simulation Cases (.hsc) in the same folder as the relief valves Microsoft Database (.mdb) file.

To do this, navigate to the Save As window from the File menu in Aspen HYSYS, and save the file as depicted in Figure 34.

Alternatively, a save file message will also be displayed if Aspen HYSYS is closed before saving.

Figure 34. Saving As HYSYS Simulation Case or HYSYS Compound File

Once the Aspen HYSYS file is saved in the proper format, open Aspen Flare System Analyzer. When the program is

opened, navigate to the File menu, scroll over Import Sources, and then click the HYSYS Relief Valve Sources option,

shown in Figure 35.


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Figure 35. Importing HYSYS Relief Valve Sizing Results

The import window for relief valves sized in Aspen HYSYS will be queued. Click the Browse button and select the Aspen

HYSYS file in which relief valves were sized. Finally, click the Upload HYSYS File button shown below.

Figure 36. Uploading a HYSYS File for Import

When a HYSYS file has been uploaded, the window will display the device names for each PSV imported from Aspen

HYSYS. Flare sources should then be specified for each valve being used in the flare network. Flare sources can either be

selected from a blocks present on the flare flowsheet or can be created by typing a name in the Flare Source column and

hitting enter. After the mapping is done, the other flare scenarios will remember the source mapping to simplify the

creation of extra scenario mappings. The user can also decide to rename the flare sources to match the HYSYS names so

they are automatically recognized by the flare analyzer for future importing. The information imported from Aspen HYSYS

can also be used for multiple flare cases using the Flare Scenario view on the left in Figure 37. To create a new flare

scenario, click the option and enter a name. A single import file is used to house all the mappings for

multiple flare scenarios from one HYSYS case.


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Figure 37. Entering Flare Sources and Multiple Flare Scenarios

Adding overpressure protection scenarios for each flare source can either be done manually or through the Auto-Map

Scenarios feature. The Auto-Map Scenarios feature allows for a quick search and selection of overpressure protection

scenarios that adhere to certain criteria. For example, if a flare scenario was being designed to only handle fire relief

contingencies, the Auto-Map tool could be used to look up all fire contingencies imported.

First, after opening the Auto-Mapping form, choose the flare scenario for which overpressure cases are being selected.

Then, choose whether to search HYSYS valves and contingencies by overpressure scenario type or name. Figure 38 shows

a flare scenario being mapped for only fire protection cases.

Figure 38. Auto-Mapping for Different Scenarios

It is recommended to save the imported set of valve sizes by clicking Save Import Set before continuing with subsequent

flare system design and rating. In Flare Analyzer V8.4, exiting this form will prompt you to save the file. After importing

the relief valve sizing results from Aspen HYSYS into Aspen Flare System Analyzer and saving the set, click OK to

continue to flare system design.


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Relief Valve Sizing and Dynamic SimulationRelief valve sizing in Aspen HYSYS is compatible with dynamic simulation using Aspen HYSYS Dynamics. This feature is

useful when relieving conditions and fluid properties from those at steady-state operation, namely when a relief scenario

is triggered by a disturbance to steady-state operation. Dynamic simulation allows the user to obtain precise fluid

property measurements at a given point that can then be automatically referenced by the relief valve sizing tool.

To use Aspen HYSYS Dynamics and relief valve sizing together, a dynamic model must first be set up and run in Aspen

HYSYS Dynamics. For more information on completing this task, please refer to the

Aspen HYSYS Dynamics Jump Start Guide.

When the dynamic simulation has reached the process conditions at which relief valve sizing is desired, simply stop the

dynamic simulation by selecting the Stop option under the Dynamics tab on the Aspen HYSYS ribbon, as shown below in

Figure 39. Strip charts are helpful in showing the progression of a dynamic simulation and can be used to determine when

to stop the dynamic simulation.

Figure 39. Stopping Dynamic Simulation

After dynamic simulation is stopped, proceed to the Safety Analysis environment using one of the options displayed in

either Figure 1 or Figure 2. Then, the workflow for setting up and completing sizing for pressure relief valves that was

described in the previous sections of this guide should be followed in order to size a PSV.

Aspen HYSYS Dynamics can also be used to rate relief valves after obtaining a valve size in the Safety Analysis

environment. After adding a relief valve block to a simulation from the model palette (Figure 40), the set pressure and fullopen pressure for the valve should be defined in the Design tab inside the relief valve window (Figure 41), followed by

entering the sizing information under the Rating tab for the valve, as shown in Figure 42.
http://www.aspentech.com/Jump_Start-HYSYS_Dynamics_V8/http://www.aspentech.com/Jump_Start-HYSYS_Dynamics_V8/


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Figure 40: Model Palette with Relief Valve Option

Figure 41: Set Pressure and Full Open Pressure are Defined in the Design Tab


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Figure 42: Enter Sizing Information for the Valve

Once the valve is set up, a dynamic simulation can be run to see the valves performance when a processs steady-state

operation is disturbed.


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ConclusionsPressure relief valve design and sizing can be a tedious, lengthy process. Relief valve sizing in Aspen HYSYS allows the

user to design pressure relief valves quickly using a small amount of process information at the location of the valve.

Aspen HYSYS now encompasses all facets of the valve design process into one convenient location. In addition, various

scenarios involving multiple valves can be explored to find the most optimal relief schedule for a unit.

Aspen HYSYS can also serve as an accuracy check to ensure that safety equipment has been properly rated and will

perform properly, if needed. It helps designers complete their work faster so that safety equipment can be installed and

implemented sooner. All processes need to have proper safety precautions to avoid disaster and Aspen HYSYS continues

to help make all processes as safe as possible with each use.

References1. American Petroleum Inst., Sizing Selection, and Installation of Pressure-Relieving Devices in Refineries, ANSI/API RP

520, 8th Ed., Part 1: Sizing and Selection, Washington D.C., Dec. 2008.

Additional Resources

Public Website:

http://www.aspentech.com/products/aspen-hysys.aspx

Online Training:

http://www.aspentech.com/products/aspen-online-training

AspenTech YouTube Channel:

http://www.youtube.com/user/aspentechnologyinc


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Documents

JS Pressure Safety Valve Final