1. The document discusses procedures for calculating pressure safety valve (PSV) sizes for various scenarios that could lead to overpressure. It covers scenarios like closed outlets, external fires, control valve failures, hydraulic expansion, heat exchanger tube ruptures, and power or cooling failures.
2. Calculation methods include enthalpy balances for fractionating columns and the use of relief equations specified in codes like API 521. Worst cases are chosen from all possible scenarios to determine the required PSV size.
3. Key scenarios discussed in detail include closed outlets on vessels, external fires, failures of automatic controls, hydraulic expansion, heat exchanger tube ruptures, total and partial power failures, reflux losses,
Safety is the most important factor in designing a process system. Some undesired conditions might happen leading to damage in a system. Control systems might be installed to prevent such conditions, but a second safety device is also needed. One kind of safety device which is commonly used in the processing industry is the relief valve. A relief valve is a type of valve to control or limit the pressure in a system by allowing the pressurised fluid to flow out from the system.
Excel sheet Download Link: https://www.scribd.com/document/385945712/PSV-Sizing-Tool-API-Based-Calc-Sheets
PSV Sizing for Blocked Liquid Discharge Condition
PSV Sizing for Blocked Gas Discharge Condition
PSV Sizing for Fire Case of Liquid Filled Vessel
PSV Sizing for Control Valve Fail Open Case
Relief Valve Sizing for Thermal Expansion
Restriction Orifice Sizing for Gas Flow
Restriction Orifice Sizing for Liquid Flow
Single Phase Flow Line Sizing Tool
Gas Control Valve Sizing Tool
Safety is the most important factor in designing a process system. Some undesired conditions might happen leading to damage in a system. Control systems might be installed to prevent such conditions, but a second safety device is also needed. One kind of safety device which is commonly used in the processing industry is the relief valve. A relief valve is a type of valve to control or limit the pressure in a system by allowing the pressurised fluid to flow out from the system.
Excel sheet Download Link: https://www.scribd.com/document/385945712/PSV-Sizing-Tool-API-Based-Calc-Sheets
PSV Sizing for Blocked Liquid Discharge Condition
PSV Sizing for Blocked Gas Discharge Condition
PSV Sizing for Fire Case of Liquid Filled Vessel
PSV Sizing for Control Valve Fail Open Case
Relief Valve Sizing for Thermal Expansion
Restriction Orifice Sizing for Gas Flow
Restriction Orifice Sizing for Liquid Flow
Single Phase Flow Line Sizing Tool
Gas Control Valve Sizing Tool
This presentation is a brief descriptive procedure of simulating in aspen flare system analyser (otherwise called as flarenet). It gives a step by step instructions to develop a flare network scheme in the simulator
Pressure Relief Valve Sizing for Single Phase FlowVikram Sharma
This presentation file provides a quick refresher to pressure relief valve sizing for single phase flow. The calculation guideline is as per API Std 520.
Pressure Safety Valve Sizing - API 520/521/526Vijay Sarathy
No chemical process facility is immune to the risk of overpressure to avoid dictating the necessity for overpressure protection. For every situation that demands safe containment of process gas, it becomes an obligation for engineers to equally provide pressure relieving and flaring provisions wherever necessary. The levels of protection are hierarchical, starting with designing an inherently safe process to avoid overpressure followed by providing alarms for operators to intervene and Emergency Shutdown provisions through ESD and SIL rated instrumentation. Beyond these design and instrument based protection measures, the philosophy of containment and abatement steps such as pressure relieving devices, flares, physical dikes and Emergency Response Services is employed
Accumulation and Over-pressure: difference between accumulation and overpressureVarun Patel
Accumulation is pressure above the maximum allowable working pressure that vessel experience during high pressure event. Hence, when we say ‘accumulation’, its mean we are talking about the vessel or equipment.
On the other hand, Overpressure is pressure above the set pressure of the pressure safety valve that PSV experience during high pressure event. Hence, when we say ‘accumulation’, its mean we are talking about the pressure relief valve.
This presentation covers process safety considerations and when a dynamic simulation is required. We also provide a modelling approach and a case study on Coker Bottoms Steam Generator, which includes information on device selection and device sizing.
CENTRIFUGAL COMPRESSOR SETTLE OUT CONDITIONS TUTORIALVijay Sarathy
Centrifugal Compressors are a preferred choice in gas transportation industry, mainly due to their ability to cater to varying loads. In the event of a compressor shutdown as a planned event, i.e., normal shutdown (NSD), the anti-surge valve is opened to recycle gas from the discharge back to the suction (thereby moving the operating point away from the surge line) and the compressor is tripped via the driver (electric motor or Gas turbine / Steam Turbine). In the case of an unplanned event, i.e., emergency shutdown such as power failure, the compressor trips first followed by the anti-surge valve opening. In doing so, the gas content in the suction side & discharge side mix.
Therefore, settle out conditions is explained as the equilibrium pressure and temperature reached in the compressor piping and equipment volume following a compressor shutdown
Troubleshooting in Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 FLOW DIAGRAM FOR TROUBLESHOOTING
5 GENERAL APPRAISAL OF PROBLEM
5.1 Is the Problem Real?
5.2 What Is the Magnitude of the Problem?
5.3 Is it the Column or the Associated Equipment which is Causing the Problem?
6 PROBLEMS IN THE COLUMN
6.1 Capacity Problems
6.2 Efficiency Problems
7 PROBLEMS OUTSIDE THE COLUMN
7.1 Effect of Other Units on Column Performance
7.2 Column Control System
7.3 Improper Operating Conditions
7.4 Auxiliary Equipment
8 USEFUL BACKGROUND READING
9 BIBLIOGRAPHY
FIGURES
1 FLOW DIAGRAM FOR TROUBLESHOOTING
2 DETERMINATION OF COLUMN CAPACITY
Design Calculations of Venting in Atmospheric and Low-pressure Storage Tanks ...Pradeep Dhondi
hi
i have made an excel base software base on API st.2000 "Design Calculations of Venting in Atmospheric and Low-pressure Storage Tanks" to make calculation easy and accurate , i have take many case study and verified my software got positive result.
if you think you need this software for design the vent , please go to "rajiravi.ml" website there you can find complete information base on software and information based on contact etc...
This presentation is a brief descriptive procedure of simulating in aspen flare system analyser (otherwise called as flarenet). It gives a step by step instructions to develop a flare network scheme in the simulator
Pressure Relief Valve Sizing for Single Phase FlowVikram Sharma
This presentation file provides a quick refresher to pressure relief valve sizing for single phase flow. The calculation guideline is as per API Std 520.
Pressure Safety Valve Sizing - API 520/521/526Vijay Sarathy
No chemical process facility is immune to the risk of overpressure to avoid dictating the necessity for overpressure protection. For every situation that demands safe containment of process gas, it becomes an obligation for engineers to equally provide pressure relieving and flaring provisions wherever necessary. The levels of protection are hierarchical, starting with designing an inherently safe process to avoid overpressure followed by providing alarms for operators to intervene and Emergency Shutdown provisions through ESD and SIL rated instrumentation. Beyond these design and instrument based protection measures, the philosophy of containment and abatement steps such as pressure relieving devices, flares, physical dikes and Emergency Response Services is employed
Accumulation and Over-pressure: difference between accumulation and overpressureVarun Patel
Accumulation is pressure above the maximum allowable working pressure that vessel experience during high pressure event. Hence, when we say ‘accumulation’, its mean we are talking about the vessel or equipment.
On the other hand, Overpressure is pressure above the set pressure of the pressure safety valve that PSV experience during high pressure event. Hence, when we say ‘accumulation’, its mean we are talking about the pressure relief valve.
This presentation covers process safety considerations and when a dynamic simulation is required. We also provide a modelling approach and a case study on Coker Bottoms Steam Generator, which includes information on device selection and device sizing.
CENTRIFUGAL COMPRESSOR SETTLE OUT CONDITIONS TUTORIALVijay Sarathy
Centrifugal Compressors are a preferred choice in gas transportation industry, mainly due to their ability to cater to varying loads. In the event of a compressor shutdown as a planned event, i.e., normal shutdown (NSD), the anti-surge valve is opened to recycle gas from the discharge back to the suction (thereby moving the operating point away from the surge line) and the compressor is tripped via the driver (electric motor or Gas turbine / Steam Turbine). In the case of an unplanned event, i.e., emergency shutdown such as power failure, the compressor trips first followed by the anti-surge valve opening. In doing so, the gas content in the suction side & discharge side mix.
Therefore, settle out conditions is explained as the equilibrium pressure and temperature reached in the compressor piping and equipment volume following a compressor shutdown
Troubleshooting in Distillation Columns
0 INTRODUCTION/PURPOSE
1 SCOPE
2 FIELD OF APPLICATION
3 DEFINITIONS
4 FLOW DIAGRAM FOR TROUBLESHOOTING
5 GENERAL APPRAISAL OF PROBLEM
5.1 Is the Problem Real?
5.2 What Is the Magnitude of the Problem?
5.3 Is it the Column or the Associated Equipment which is Causing the Problem?
6 PROBLEMS IN THE COLUMN
6.1 Capacity Problems
6.2 Efficiency Problems
7 PROBLEMS OUTSIDE THE COLUMN
7.1 Effect of Other Units on Column Performance
7.2 Column Control System
7.3 Improper Operating Conditions
7.4 Auxiliary Equipment
8 USEFUL BACKGROUND READING
9 BIBLIOGRAPHY
FIGURES
1 FLOW DIAGRAM FOR TROUBLESHOOTING
2 DETERMINATION OF COLUMN CAPACITY
Design Calculations of Venting in Atmospheric and Low-pressure Storage Tanks ...Pradeep Dhondi
hi
i have made an excel base software base on API st.2000 "Design Calculations of Venting in Atmospheric and Low-pressure Storage Tanks" to make calculation easy and accurate , i have take many case study and verified my software got positive result.
if you think you need this software for design the vent , please go to "rajiravi.ml" website there you can find complete information base on software and information based on contact etc...
Energy losses in Bends, loss coefficient related to velocity head.Pelton Whee...Salman Jailani
In this slide you learn the how to make the lablayout and the study the Energy losses, Pelton Wheel. Kaplan TURBINE, Franices TURBine And its Efficiency of Mecahanical Power Plants..
00923006902338
I have attached this report where we find out the actual reason steam turbine Deaerating Condenser Performance degradation which was written on June 06, 2012.That time I was in Haripur Power Limited (HPL) ,A 360 MW CCPP of Pendekar Energy Bangladesh Ltd.
The report outcome showed that the Steam turbine load could be reached to its maximum capacity after those valve maintenance works on the next Steam Turbine Major inspection on 2013.We hope we can increase our steam turbine load to 5-7 MW/D on that time.
The operational guys were indicating Circulating water pumps (CWP A&B) were not performing to its design capacity & Ejectors/vacuum pumps are not performing well.So,Mechanical Maintenance Team (MMT) team find this successful outcome after several study.
Condenser vacuum condition has improved a lot after maintenance of the valves on last Major Inspection on 2013.
It is a sample report where we can realize that identifying actual reason for an equipment performance is not only a job of operational people but also a responsibility of the maintenance guys.
Centrifugal Compressor System Design & SimulationVijay Sarathy
The power point slides focuses on centrifugal compressor design, dynamic simulation including anti surge valve and hot gas bypass requirements. The topics covered are,
Centrifugal Compressor (CC) System Characteristics
Centrifugal Compressor (CC) Drivers
Typical Single Stage System
Start-up Scenario
Shutdown Scenario
Emergency Shutdown (ESD) Scenario
Centrifugal Compressor (CC) System Design Philosophy
Anti-Surge System
Recycle Arrangements
CC Driver Arrangements
General Notes
Automobile Management System Project Report.pdfKamal Acharya
The proposed project is developed to manage the automobile in the automobile dealer company. The main module in this project is login, automobile management, customer management, sales, complaints and reports. The first module is the login. The automobile showroom owner should login to the project for usage. The username and password are verified and if it is correct, next form opens. If the username and password are not correct, it shows the error message.
When a customer search for a automobile, if the automobile is available, they will be taken to a page that shows the details of the automobile including automobile name, automobile ID, quantity, price etc. “Automobile Management System” is useful for maintaining automobiles, customers effectively and hence helps for establishing good relation between customer and automobile organization. It contains various customized modules for effectively maintaining automobiles and stock information accurately and safely.
When the automobile is sold to the customer, stock will be reduced automatically. When a new purchase is made, stock will be increased automatically. While selecting automobiles for sale, the proposed software will automatically check for total number of available stock of that particular item, if the total stock of that particular item is less than 5, software will notify the user to purchase the particular item.
Also when the user tries to sale items which are not in stock, the system will prompt the user that the stock is not enough. Customers of this system can search for a automobile; can purchase a automobile easily by selecting fast. On the other hand the stock of automobiles can be maintained perfectly by the automobile shop manager overcoming the drawbacks of existing system.
Quality defects in TMT Bars, Possible causes and Potential Solutions.PrashantGoswami42
Maintaining high-quality standards in the production of TMT bars is crucial for ensuring structural integrity in construction. Addressing common defects through careful monitoring, standardized processes, and advanced technology can significantly improve the quality of TMT bars. Continuous training and adherence to quality control measures will also play a pivotal role in minimizing these defects.
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
Instead of buying and hoping for the best, we can use data science to help us predict which products may be good fits for us. It includes various function programs to do the above mentioned tasks.
Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Event Management System Vb Net Project Report.pdfKamal Acharya
In present era, the scopes of information technology growing with a very fast .We do not see any are untouched from this industry. The scope of information technology has become wider includes: Business and industry. Household Business, Communication, Education, Entertainment, Science, Medicine, Engineering, Distance Learning, Weather Forecasting. Carrier Searching and so on.
My project named “Event Management System” is software that store and maintained all events coordinated in college. It also helpful to print related reports. My project will help to record the events coordinated by faculties with their Name, Event subject, date & details in an efficient & effective ways.
In my system we have to make a system by which a user can record all events coordinated by a particular faculty. In our proposed system some more featured are added which differs it from the existing system such as security.
About
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Technical Specifications
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
Key Features
Indigenized remote control interface card suitable for MAFI system CCR equipment. Compatible for IDM8000 CCR. Backplane mounted serial and TCP/Ethernet communication module for CCR remote access. IDM 8000 CCR remote control on serial and TCP protocol.
• Remote control: Parallel or serial interface
• Compatible with MAFI CCR system
• Copatiable with IDM8000 CCR
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
Application
• Remote control: Parallel or serial interface.
• Compatible with MAFI CCR system.
• Compatible with IDM8000 CCR.
• Compatible with Backplane mount serial communication.
• Compatible with commercial and Defence aviation CCR system.
• Remote control system for accessing CCR and allied system over serial or TCP.
• Indigenized local Support/presence in India.
• Easy in configuration using DIP switches.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
2. Role of Pressure Safety Valve (PSV)
Role of Pressure Safety Valve (PSV)
PSVs are installed to make sure that
Accumulated Pressure ≤ Maximum Allowable Accumulated Pressure
as dictated by applicable code & standard
PressureVessels
(ASME SectVIII,API 520 & 521)
Unfired Boilers
(ASME Sect I)
Piping
(ASME B16.5 and 31.3)
2
3. Design Code & Standard (Pressure Vessel)
Design Code & Standard (Pressure Vessel)
- ASME Section VIII
- API 520 Sizing, Selection and Installation of Pressure-Relieving
Devices in Refineries
Devices in Refineries
Source : API 520
Set pressure = Pressure at which PSV is set to open
3
5. PROCEDURES FOR PSV CALCULATION
PROCEDURES FOR PSV CALCULATION
LOCATE PSV and SPECIFY
RELIEF PRESSURE
RELIEF PRESSURE
DEVELOP SCENARIOS
(WHAT CAN GO WRONG?)
CALCULATE PSV SIZE
Required Information
CHOOSE WORST CASE
DESIGN OF RELIEF SYSTEM
(Flare Header, etc)
5
6. PSV SCENARIOS
(Refer API 521)
(Refer API 521)
FOCUS ON COMMON CASES :
- Closed Outlets onVessels
- External Fire
- Failure of Automatic Controls
- Hydraulic Expansion
Hydraulic Expansion
- Heat ExchangerTube Rupture
- Total Power Failure
P i l P F il
- Partial Power Failure
- CoolingWater Failure
- Reflux Loss
- Failure of Air-Cooled Heat X
DOUBLE JEOPARDY NOT
CONSIDERED
6
(Simultaneous occurrence of two or
more unrelated causes of
overpressure) Source : API 521
7. Closed outlets on vessels
Closed outlets on vessels
Cause
Outlet valve is blocked while there is
i i l f hi h
continuous inlet from high pressure
source
Effects
Outlet valve closed
Effects
Pressure built-up in vessel
Calculation
Can PSV be opened in Closed Outlet Case? R li f
Pressure source (pump, compressor,
high pressure header)
No
Calculation
Can PSV be opened in Closed Outlet Case?
(Is maximum inlet pressure > PSV set pressure?)
For pump :
Is maximum pump shut off pressure ≥ PSV set
Relief case not
considered
Relief rate =
Yes
No
Is maximum pump shut-off pressure ≥ PSV set
pressure?
Relief rate
maximum inlet flow
7
8. External Fire (1/4)
External Fire (1/4)
Cause
External pool fire caused by accumulated hydrocarbon on the
ground or other surfaces
Effects
Effects
- Vaporization of liquid inside the vessel,
leading to pressure building up within the vessel
g p g p
Calculation
Refer next slides
Refer next slides
8
9. External Fire - Liq. Vessel (2/4)
External Fire Liq. Vessel (2/4)
Relief rate (W) = Heat absorbed by liquid from external fire (Q)
Latent Heat ofVaporization of liquid (λ)
Case 1 :
If adequate drainage necessary to control the spread of major
ill f t th d t t l f d i
spills from one area to another and to control surface drainage
and refinery waste water.
Q = 43,200 x F x A0.82
C 2
7 6 m Case 2 :
If adequate drainage and firefighting equipment do not exist.
Q = 70,900 x F x A0.82
7.6 m
Q = Heat absorbed by liquid from external fire(W)
F = Environment Factor
A = Wetted Surface Area (m2)
9
10. External Fire - Liq. Vessel (3/4)
External Fire Liq. Vessel (3/4)
Wetted Surface Area (A)
Source : API 521
10
11. External Fire
Liq. Vessel (4/4)
Environment Factor (F)
Liq. Vessel (4/4)
Latent Heat ofVaporization of liquid (λ)
for multi-component mixture
5 wt% flashed
λ = Dew PointVapor Enthalpy
Relief Pressure
Bubble point T
– Bubble Point Liquid Enthalpy
For column, use composition of
For column, use composition of
1. Second tray from top (or reflux
composition if unavailable)
2. Bottoms
Ch th t i l PSV i
Source : API 521
Choose one that require larger PSV size
11
12. Failure of Automatic Control (1/3)
Failure of Automatic Control (1/3)
Cause
- Failure of a single automatic control valve Consider this control valve fail
- Control valves are assumed to fail to non-favorable
position (not necessarily to their specified fail
position).
Consider this control valve fail
in full-open although it is
specified as “fail-close”
Effects
- Control valve fail open : maximum fluid flow
through valve
N2
Header
Flare
FC FO
SPLIT-RANGE
g
- Control valve fail close : no fluid flow
- Effect of control valve fail open or close to be
considered on case-by-case basis
FC FO
PIC
Calculation
Calculation of maximum fluid flow in control valve
fail open case, refer next slide
p ,
12
13. Failure of Automatic Control (2/3)
Failure of Automatic Control (2/3)
CALCULATION OF MAX. FLOW THROUGH CONTROL VALVES
1. Find Valve CV value (from manufacturer).
2. If by-pass valve is installed, consider possibility that by-pass
valve may be partially open Add 50% margin to CV value in
valve may be partially open. Add 50% margin to CV value in
1.
3. For Calculate maximum flow through control valve (refer
calculation sheet)
4. Find relief rate (to consider on case-by-case basis)
13
14. Failure of Automatic Control (1/3)
Failure of Automatic Control (1/3)
EXAMPLE :
1 FEED SURGE DRUM
N2
Header
Flare
PV01 PV02
SPLIT-RANGE
1. FEED SURGE DRUM
Relief rate = maximum flow through PV01 –
flow through PV02
Header PV01 PV02
PIC
flow through PV02
2. LPGVAPORIZER
Relief rate =
LPG Generated by max. steam flow
– normal LPG outlet flow
14
15. Hydraulic expansion (1/2)
Hydraulic expansion (1/2)
Cause
Liquid is blocked in and later heated up (by hot fluid steam
Liquid is blocked-in and later heated up (by hot fluid, steam
tracing / jacket or by solar radiation).
Effects
Liquid expands upon heating, leading to pressure build-up in
vessel or blocked in section of piping/pipeline.
15
16. Hydraulic expansion (1/2)
Hydraulic expansion (1/2)
Calculation
Refer calculation sheet for relief rate calculation
If applicable (e.g. in
cooling circuit) consider
cooling circuit), consider
administrative control in
place of relief valve.
16
17. Heat Exchanger Tube Rupture (1/3)
Heat Exchanger Tube Rupture (1/3)
Cause
Tube rupture in shell & tube heat exchanger exposing lower
Tube rupture in shell & tube heat exchanger, exposing lower
pressure side to high pressure fluid.
Effects
Effects
Lower pressure side is exposed to high pressure fluid
Note : No need to consider if design pressure of lower pressure
g p p
side is 10/13 or more of design pressure of high pressure side.
Calculation
Use orifice equation with
double cross-sectional area.
17
20. Total Power Failure (1/5)
Total Power Failure (1/5)
Cause
Di i i l l di l i l f il f h
Disruption in power supply, leading to electrical power failure of the
whole site.
Effects
- Loss of operation for pumps, air-cooled heat exchangers, all electrically-
driven equipments
- For Fractionating Column worst case design, assume steam system
continues to operate
Calculation
For Fractionation Column : Enthalpy Balance Method
Note
Usually controlling case for flare capacity
20
21. Total Power Failure (2/5)
Total Power Failure (2/5)
Enthalpy balance around Fractionator Column to find
excess heat (Q), which would cause vapor generation.
QC
FEED DISTILLATE
HF HD
F D
QR
BOTTOMS
HB
B
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
Note : All values are taken from relieving condition
21
22. Total Power Failure (3/5)
Total Power Failure (3/5)
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
All t l f f d di till t d b tt
All pumps stop loss of feed, distillate and bottoms
Condenser Duty (QC)
1. Water-cooled (QC = 0)
2 Air-cooled
2. Air-cooled
May consider credit
for natural draft effects
(20 30% of normal duty)
(20-30% of normal duty)
22
23. Total Power Failure (4/5)
Total Power Failure (4/5)
Reboiler Duty (QR)
1. Thermosyphon using steam
(Q = Normal Duty)
2. Fired Heater
No flow to fired heater, but consider the
possibility that remaining fluid inside tube is
(QR = Normal Duty) p y g
heated up by heat from refractory surfaces
(QR = 30% of normal duty)
Steam
High Integrity Pressure Protection System (HIPPS)
2. Fired Heater
Heat from refractory surfaces
1. Thermosyphon using steam
(QR = 0)
(QR = 30% of normal duty)
( R )
FUEL
23
24. Total Power Failure (5/5)
Total Power Failure (5/5)
Relief load =V
Vapor cannot be condensed
(loss of condenser duty)
Relief Load = Vapor generated by excess heat
= Excess Heat (Q)
Latent Heat ofVaporization of 2nd tray liquid
Vapor generated (V)
Latent Heat ofVaporization of 2 tray liquid
Excess Heat (Q)
24
25. Partial Power Failure (1/3)
Partial Power Failure (1/3)
Cause
Disruption in a single feeder, bus, circuit or line, leading to partial power
failure
Effects
- Varies, pending on power distribution system
- For Fractionating Column, worst case considered for Partial Power
Failure is simultaneous loss of reflux pump and air-cooled condenser,
while there is continuous heat input into column
while there is continuous heat input into column.
Calculation
For Fractionating Column : Enthalpy Balance Method
g py
Internal Reflux Method (alternative)
Note
Usually controlling case for column PSV sizing
Usually controlling case for column PSV sizing
25
26. Partial Power Failure (2/3)
Partial Power Failure (2/3)
Worst case : simultaneous loss of reflux pump and air-
cooled condenser
QC
FEED DISTILLATE
HF HD
F D
QR
BOTTOMS
HB
B
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
26
27. Partial Power Failure (3/3)
Partial Power Failure (3/3)
Temp (TH)
Latent Heat of Vaporization (λH)
Mass Flow (mH)
( H)
Reflux
Specific heat (Cp,R)
Mass flow (mR) , Temp (TR)
Internal Reflux
Mass flow (mIR) Alternative : Internal reflux method
Relief load = mH + mIR
mRCp,R(TR-TH) + mIRλH = 0
m m C (T -T )
Relief load mH mIR
mIR = mRCp,R(TH-TR)
λH
27
28. Cooling Water Failure (1/3)
Cooling Water Failure (1/3)
Cause
Cooling Water Pump failure loss of make up water etc
Cooling Water Pump failure, loss of make-up water, etc.
Effects
Loss of duty for water cooled heat exchangers
- Loss of duty for water-cooled heat exchangers
- Operation of pumps that require cooling water for lube oil cooling may
also be effected
Calculation
Calculation
For Fractionating Column : Enthalpy Balance Method
Internal Reflux Method (Alternative)
28
29. Cooling Water Failure (2/3)
Cooling Water Failure (2/3)
QC
HF
HD
FEED DISTILLATE
F
D
Q
BOTTOMS
HB
B
QR
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
Note : Need to recalculate D and HD
Alternative : Internal Reflux Method (refer Partial Power Failure case
(
with re-calculated reflux temp, flowrate and specific heat)
29
30. Cooling Water Failure (3/3)
Cooling Water Failure (3/3)
Temp (TH)
Latent Heat of Vaporization (λH)
Mass Flow (mH)
( H)
mRCp,R(TR-TH) + mIRλH = 0
mIR = mRCp R(TH-TR)
Alternative : Internal reflux method
Reflux
Specific heat (Cp,R)
Mass flow (mR) , Temp (TR)
IR R p,R( H R)
λH
Internal Reflux
Mass flow (mIR)
1. Find internal reflux without considering cooling
water failure (mIR,normal)
2. Recalculate reflux flowrate, temperature and
specific heat for cooling water failure case
3. Find internal reflux considering cooling water
failure (mIR,CWFail)
4 Relief load = overhead vapor normal +
30
4. Relief load overhead vapor_normal +
(mIR,normal - mIR,CWFail )
31. Reflux Loss(1/2)
Reflux Loss(1/2)
Cause
Failure of reflux pumps
Failure of reflux pumps
Effects
Loss of reflux to column
- Loss of reflux to column
- Liquid level in overhead receiver rises, ultimately flooding the condenser,
causing loss of condensing duty
Calculation
Calculation
For Fractionating Column : Enthalpy Balance Method
Alternative : Internal Reflux Method
31
32. Reflux Loss (2/2)
Reflux Loss (2/2)
Q
H
QC
FEED
HF
F
HD
D
DISTILLATE
HB
B
BOTTOMS
QR
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
B
BOTTOMS
Alternative : Internal Reflux Method (refer Partial Power Failure case)
32
33. Failure of air-cooled heat exchanger (1/2)
Failure of air cooled heat exchanger (1/2)
Cause
l f d d l l d h h
Failure of individual air-cooled heat exchanger
Effects
- Loss of condensing duty in fractionating column
Calculation
For Fractionating Column : Enthalpy Balance Method
Internal Reflux Method (Alternative)
33
34. Failure of air-cooled heat exchanger (2/2)
Failure of air cooled heat exchanger (2/2)
QC
H H
QC
FEED DISTILLATE
HF
F
HD
D
BOTTOMS
HB
B
QR
Excess Heat (Q) = HFF – HDD – HBB – QC + QR
B
Note : Need to recalculate D and HD
Alternative : Internal Reflux Method (refer cooling water failure case)
34