Forum Archive

Recently, I noticed that some of the old discussions on the Chemwork forum are not available anymore. It seems LinkedIn does not have the capacity to archive group discussions and activity updates beyond a certain time.

As a gratitude to those who devote their valuable time to share their experience with others, I upload the discussions on this page after they disappear on the forum.

Visit Chemwork discussion forum if you are interested to contribute.

Flare Knock out Drum sizing standard
Lesson Learned Hysys/UniSim Dynamic Depressuring Utility: Heater Type
Vessel Internal of Three Phase Test Separator
Temperature increase across Molecular Sieve Bed
Selection of Type of Pilot Operated Relief Valve: Pop Action and Modulating Action
Modelling of Blowdown Valve in Flarenet
Scrubber liquid outlet line design conditions
Molecular sieve bed regeneration: How to rate the condenser
HYSYS Dynamic Depressuring Utility: "Prevent Temperature Cross" Option
What are the important factors to consider is designing three stage separator
Is it necessary to consider PSV for heat exchanger at external fire?
PSV line sizing and 3% pressure drop check in Hysys' PSV module
The selection & installation criteria of ROIV (Remotely Operated Isolation Valves) for emergency
Overflow Weir Type Three Phase Separator Rating
How to Size a Gas Filter
Exceeding maximum gas velocity - stoner pipeline simulation
Spare Philosophy for Fire Scenarios
Determine the relief rate for fire case when relieving condition is supercritical
What is the safe margin with lower explosive limit (LEL) so that a combustible vapor mixture will not ignite?
Design a Flare KO Drum for Maximum Liquid Relief During Cold Depressurising
What's the source for inlet nozzle sizing criteria?
Is there any difference in the relief rate if a control valve is replaced with manual valve?
What is the minimum temp. difference between dew point & temperature of flue gas at fired heater stack
Plant/Utility air requirement for each equipment at Plant
PSV Sizing for Tube Rupture Scenario
What is the conservative approach to estimate isentropic expansion coefficient?
Actual flow condition in relief systems is normally somewhere btw isothermal & adiabatic
Why LPG storage vessels are termed as bullets? why they are in cylindrical form ?
Accurate simulation of H2S and CO2 partitioning
PVRV and PCV Arrangement on the Tank
What is the feed gas composition for GTL plant?
Selection Criteria for Blowdown Valve Locations and No of BDV's for Gas Dehydration & Gas Sweetening
Plant tripping on low-low pressure of fire water ring main
What is the application of "Static Head Contribution" in "Pipe" Methods Tab in Flarenet 2006.5?
Slug catcher Depressuring Time
Do We Need a High Pressure IPF for Flare Network?
How to determine the minimum required purge rate for the flare riser
Why we require PSV on water injection centrifugal pump discharge line
Two Phase Separator Drum Sizing "Flow Path" length and "Tan-Tan" length
Requirement of auto-start for pumps
Anti surge take-off location for a centrifugal compressor
Why don't we prefer the finned tube when steam is condensing in the shell side of heat exchanger?
Why we use the steam stripping in crude distillation instead of reboiler?
Fire wall requirement
Flare K.O. Drum Sizing
Interview Questions for Process Engineers
Calculating the Nitrogen consumption for deminerilized water storage tank blanketing
On-line leak sealing - Engineering Standards
Pumping the flashing liquid
How to determine which relief stream should be routed to the Acid Gas Flare
Centrifugal Compressor Relief for the Blocked Outlet Case
Using the nitrogen enriched gas (14% nitrogen) as fuel for the gas engine
Flare Stack Design
Why to depressurize the gas compression train immediately after shutdown
Flare for Aromatic Complex in the centralized waste treatment
Depressurization Case Study for Reciprocating Compressor Station
Restriction Orifice Used in Many Applications in Different Manners
Length correction factor in separator sizing
How to protect the liquid pipe section between flowline check valve and isolation valve
Archimedes Number in Vane Pack face area calculation
PSV requirement on vessels as per ASME Section VIII
Cold Depressurization: Depressuring Time and Recycle Efficiency
Why diaphragm pressure transmitters are used in Well head flow lines?
Seal gas applied in centrifugal compressor
Tank Outlet Nozzle Location
Divergent & Looped Flare Networks
Comparison of Polytropic Efficiency of Natural Gas Compressor using Aspen HYSYS & Manual Calculation
How to calculate the minimum amount of air needed for hydrocarbon mixture to ignite
What Do I Need To Know About Two Phase Flow?
How to apply valve equation in HYSYS Depressuring?
High Pressure Injection Pumps: PSV's set point
Cp/Cv for Centrifugal Compressor - Ideal or Real Condition?
Do you switch the duty and standby pumps in operation?
Comparison Of Line Packing Using Aspen Plus Dynamics and Manual Calculations
Floating Roof Tank Overpressure Protection
Why Line Sizes above 24" Are Avoided as far as possible?
Control Valve Failure : Do you consider "both control valve and bypass wide open" a remote contingency?
Estimate Depressuring Load When Software Is not Available
Relief Study for Control Valve Failure Scenario: Mechanical Cv Limiter (Stop) Option
Annulus Gas Removal
Are Storage Tanks' Thermal Breathings Plant-Wide Scenarios?
Design Pressure for Storage Tank with Electric Heater
Enhanced Oil Recovery - CO2 injection in dense phase
Fuel Gas KO Drum Bypass: Doesn't it defeat the purpose of KOD ?
Viscosity Tuning
Actuated Reduced Bore Valve
Can LTCS temperature limit be increased beyond -46 deg C by taking credit of impact test?
How the amount of seal gas is determined based on the settle out pressure of the compressor
Back flow through the compressor discharge NRV
Non-Return Valve (NRV) Bypass: doesn't it defeat the purpose of NRV ?
HAZOP Study: MOV Operability and Isolation
Allowable Accumulation for Remote Contingency Overpressure Scenarios
Have You Experienced Continuous Back Pressure within Closed Drain Network?
Provision of Start-Up Circulation Line for Pump
Low flow protection for thyristor control electrical heaters
Chemical Injection Quill Pressure Drop
How to drain a pressurized hot oil system operating at 380 Deg C
PSV inlet pipe sizing
Overboard dump valve in Fire Water System
Bypassing trips during planned startup/shutdown or for maintenance
When do we give pressure equalization across valves
Reverse flow condition for water injection pumps
How to calculate the flow rate of motive fluid in an ejector
Outlet temperature of PSV and BDV
What is the mitigation, if relieving temperature is greater than vessel wall temperature
Fail safe position of control valves to flare
Compressor control, load sharing and anti-surge
BDV installation criteria based on API 521
Closed drain drum heater
Non-slam check valve for gas service
Determination of hydrate formation temperature at LP flare header
Hydrate formation concern for flare network
The basis for fire de pressuring calculations
Compressor on total recycle
Provision of spare nozzle for vessels and storage tanks
What is the applicable relief scenarios for pig launcher
PSV inlet line sizing
Fire heat flux to un wetted vessels for de pressuring calculations
Can we take credit of SDV closure to avoid gas blow-by scenario to downstream system
Whether to take credit for normal flow rate during PCV failure open scenario
Methanol rate for hydrate inhibition
Determination of distillation tower working pressure
Pump end of curve operating point
Validity of API 521 method for sonic flare stacks
Pump auto-start time
Using fuel gas as motive gas for ejector
When we would use a side re boiler (pump around) for our distillation tower
Why 21% overpressure is considered in fire case PSV sizing scenario
What is the best way for pump efficiency estimation without having vendor information
Vent to safe location
What are the engineering codes to design tank with submerged coil
Requirement of dispersion studies for ignition sources
Blocked outlet PSV on centrifugal compressor discharge
MEG injection in gas dew point control
Calculating liquid level in a cylinder
Setting of de pressuring model details
How extensive should be FEED endorsement
Relief rate calculation for control valve failure
Flare network purging upon hot gas relief
Compressor behavior
Foaming in absorber column for gas dehydration unit
Storage tank PVRV set points
Glycol rate for chilling (EG) and contactor (TEG) systems
What is the basis for selecting submerged weir & overflow weir
Tracing of the compressor suction line
External reflux ratio and actual number of trays in a fractionation column
Vapour recovery unit compressor
Pump suction line - detail design
Tank blanketing gas design considerations
Selection of heating system for tankage oil terminal where no utility is available
Fire, heat exchanger and relief load
PSV relief load calculation in supercritical condition
Finger type or vessel slug catcher
Booster pump capacity
Contraction and expansion pressure drop
Pump vent line
Tank flame arrestor pressure drop
Flowmeter temperature measurement
Whether surge analysis is imperative in fire fighting network
Design pressure of vacuum pump
Isolation-vent-drain for PSVs on the chemical dosing systems
Crude oil sweetening
Compressor hot gas bypass valve
How the pressure drop changes from bottom to top of distillation column
PSV load calculation for gas expansion fire case
Is it safe to route continuous drain to closed drain drum
Providing XV on the instrument air header to GTG, is it safe
N2 consumption for continuous purge of vent boom during startup
Effect of steam or hot oil supply temperature on design temperature of the distillation column
Nozzle momentum criteria for KODs
Installation of RO downstream of blowdown valve
Oil and gas separation - number of stages and stage pressures
Plant turndown operation
About designing an explosion proof flare system
Gas blow-by from a production separator to tank
For LPG recovery plant, which venting system is more recommended burn pit or flare
Initial temperature for flare design
How to calculate the latent heat of a multi component mixture
Kicker line (pig launcher / receiver) sizing criteria
Level control on well head stack knock out drum
Oversizing of separator nozzles - any disadvantages
The calculation of PSV for two phase relief (API 520 Part 1 annex C) yielding big sizes
Triple offset butterfly valves (TOBV); Are they future valves
Horizontal vessel slope requirement
Degradation of glycol in TEG reboiler
The basis of momentum criteria for flare system
Slurry system (liquid+sand) pressure drop
Single pass shell countercurrent heat exchanger
Should PSV connection be taken from the pump discharge line highest point
Why line sizes above 24 inches are avoided as far as possible
How to drain a pressurized hot oil system operating at 380 Deg C
Is it necessary to consider heat exchanger relief load for sizing PSVs at external fire
Whether to use 2/3 rule or 10/13 rule
Latent heat of vaporization via flash calculations
Vessel internal of three phase test separator
Is it safe to use fuel gas as tank blanketing gas
PSV sizing for tube rupture scenario
Heat exchanger tube rupture
Is there any way to estimate the duty of a heat exchanger knowing only its geometry
What if relieving temperature is greater than an unwetted vessel wall temperature under fire
Aging factor & hydraulic calculation
Blowdown valve allowable backpressure
Bypassing trips during planned startup, shutdown or maintenance
Double solenoid valves in shutdown systems
Duplication of pressure and level transmitters
Gas blow-by from high pressure vessel to the closed drain sump vessel
Gas compressor dry gas seal
Hydraulic double acting actuated valves
Increased venting requirements for atmospheric and low pressure storage tanks
Is there a minimum value of L over D below which Darcy-Weisbach equation is usually not applied
Pressure drop calculated by Flarenet in PSV outlet flange
PSV load calculation for HIPPS valve leakage rate
Separate flare headers for cold gas and cold liquid
Suction throttling valve location for fixed speed compressors
The realistic relief capacity of PSV installed downstream a wellhead choke valve
Using the corrected hydrotest pressure for tube rupture PSV sizing


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