Hazards Analysis, Code Compliance & Procedure Development

Services to identify process safety hazards and facilitate compliance with established standards and codes.

Combustible Dust Testing

Laboratory testing to quantify dust explosion and reactivity hazards

Flammable Gas & Vapor Testing

Laboratory testing to quantify explosion hazards for vapor and gas mixtures

Chemical Reactivity Testing

Laboratory testing to quantify reactive chemical hazards, including the possibility of material incompatibility, instability, and runaway chemical reactions

ISO Accreditation and Scope
Fauske & Associates fulfills the requirements of ISO/IEC 17025:2017 in the field of Testing
DIERS Methodology

Design emergency pressure relief systems to mitigate the consequences of unwanted chemical reactivity and account for two-phase flow using the right tools and methods

Deflagrations (Dust/Vapor/Gas)

Properly size pressure relief vents to protect your processes from dust, vapor, and gas explosions

Effluent Handling

Pressure relief sizing is just the first step and it is critical to safety handle the effluent discharge from an overpressure event

Thermal Stability

Safe storage or processing requires an understanding of the possible hazards associated with sensitivity to variations in temperature


Classification of hazardous materials subject to shipping and storage regulations

Safety Data Sheets

Develop critical safety data for inclusion in SDS documents


Model transport of airborne virus aerosols to guide safe operations and ventilation upgrades


Model transport of contamination for source term and leak path factor analysis

Fire Analysis

Model transport of heat and smoke for fire analysis

Flammable or Toxic Gas

transport of flammable or toxic gas during a process upset

OSS consulting, adiabatic & reaction calorimetry and consulting

Onsite safety studies can help identify explosibility and chemical reaction hazards so that appropriate testing, simulations, or calculations are identified to support safe scale up

Mechanical, Piping, and Electrical

Engineering and testing to support safe plant operations and develop solutions to problems in heat transfer, fluid flow, electric power systems

Battery Safety

Testing to support safe design of batteries and electrical power backup facilities particularly to satisfy UL9540a ed.4

Hydrogen Safety

Testing and consulting on the explosion risks associated with devices and processes which use or produce hydrogen

Spent Fuel

Safety analysis for packaging, transport, and storage of spent nuclear fuel

Decommissioning, Decontamination and Remediation (DD&R)

Safety analysis to underpin decommissioning process at facilities which have produced or used radioactive nuclear materials

Laboratory Testing & Software Capabilities

Bespoke testing and modeling services to validate analysis of DD&R processes

Nuclear Overview

Our Nuclear Services Group is recognized for comprehensive evaluations to help commercial nuclear power plants operate efficiently and stay compliant.

Severe Accident Analysis and Risk Assessment

Expert analysis of possible risk and consequences from nuclear plant accidents

Thermal Hydraulics

Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions

Environmental Qualification (EQ) and Equipment Survivability (ES)

Testing and analysis to ensure that critical equipment will operate under adverse environmental conditions

Laboratory Testing & Software Capabilities

Testing and modeling services to support resolution of emergent safety issues at a power plant

Adiabatic Safety Calorimeters (ARSST and VSP2)

Low thermal inertial adiabatic calorimeters specially designed to provide directly scalable data that are critical to safe process design

Other Lab Equipment and Parts for the DSC/ARC/ARSST/VSP2 Calorimeters

Products and equipment for the process safety or process development laboratory


Software for emergency relief system design to ensure safe processing of reactive chemicals, including consideration of two-phase flow and runaway chemical reactions


Facility modeling software mechanistically tracks transport of heat, gasses, vapors, and aerosols for safety analysis of multi-room facilities


Our highly experienced team keeps you up-to-date on the latest process safety developments.

Process Safety Newsletter

Stay informed with our quarterly Process Safety Newsletters sharing topical articles and practical advice.


With over 40 years of industry expertise, we have a wealth of process safety knowledge to share.

Recent Posts

Vent Sizing (VSP2) User Forum – Optimizing Temperature Measurement

Posted by The Fauske Team on 05.28.14

By Charlie Askonas, Chief Testing & Safety Engineer, Fauske & Associates, LLC


The Vent Sizing Package 2™ (VSP2™) is a low thermal inertia adiabatic calorimeter used for process hazard characterization that utilizes state-of-the-art DIERS technology to obtain critical upset process design data.  It is the commercial version of the original DIERS bench scale apparatus developed by Fauske & Associates, LLC's (FAI)VSP2 illustration

Its versatile design allows the VSP2 to simulate upset (abnormal) conditions which might lead to a runaway chemical reaction (e.g. loss of cooling, loss of stirring, mischarge of reagents, mass-loaded upset, batch contamination, fire exposure heating, etc). Resulting temperature and pressure rise rates are directly scalable since it is a low thermal inertia (phi-factor) apparatus. FAI not only utilizes the VSP2™ in our fully equipped hazards laboratory but we also manufacture and sell the calorimeter for use by our clients.


The VSP2 utilizes established DIERS technology to identify and quantify process safety hazards so they can be prevented or accommodated by process design.  
Test data includes adiabatic rates of temperature and pressure change which, due to the low thermal inertia, can be directly applied to process scale to determine relief vent sizes, quench tank designs and other relief system design parameters related to process safety management.  Adiabatic data obtained with the VSP2 can be used to characterize reactive chemical and consequences that could occur due to process upset conditions.

Optimizing Temperature Measurement

To get the best temperature readings from VSP2™ tests, it is important to remember to ground the sheath of each element of the guard heater to the test cell fill line as shown in Figure 1.  Both the sheath of the lid and side elements of the guard heater should be jumpered using alligator clips to the test cell fill line.  This eliminates electrical interference from the heaters with the test cell thermocouple.  In addition (as per the VSP2™ Manual), the containment vessel should be grounded to the VSP2™ control box chassis.  Finally, the shields of the thermocouple cables where they plug in to the thermocouple gland should also be grounded to the outside of the containment vessel.  These measures help assure noise free temperature measurements.  If the FAI Super Magnetic stirrer is being used, the thermocouple cables should be oriented radially away from the containment vessel and kept above the Super Magnetic Stirrer.  This avoids interference from the strong magnetic field of the stirrer.  


The versatile configurations offered by the VSP2 design directly simulates process conditions including:

  • Loss of cooling or agitation
  • Accumulation or mischarge of reactants
  • Contamination of batch
  • Thermally initiated decomposition
  • Resident incubation time
  • In-situ liquid/gas dosing or sampling


Use of the VSP2™ can help users obtain complete chemical system data such as:

  • Low thermal inertia testing allows data to be directly applied to process scale
  • Temperature and pressure rise rates applicable to relief system design "Based on DIERS two-phase flow technology, recognized by OSHA as an example of “good engineering practice”
  • Many testing configurations
    -    Solids, liquids or two phase mixtures 
    -    Closed or open (vented) tests
    -    Scaled blowdown simulation
    -    Test cells are available in 304 & 316 SS, Hastelloy C, Titanium and glass
  • Accurate adiabatic data
    -    Onset temperature
    -    Total adiabatic temperature rise (ΔTad)
    -    Heat of reaction or mixing
    -    Vapor pressure data
    -    Time to maximum rate (tmr)
    -    Self-accelerating decomposition temperature (SADT)
  • Relief vent sizing
  • Quench tank design
  • Effluent handling
  • Critical temperature
  • Effect of two-phase flow

FAI also created PrEVent software to allow users to implement practical emergency vent sizing using industry recognized methodology.  It applies DIERS methodology (including the Leung-Omega and Fauske methods) for reactive chemistry and API 520/2000 or NFPA 30 for non-reactive systems.

For more information on the VSP2 or Adiabatic Calorimetry and Relief System Design, please contact Jeff Griffin at griffin@fauske.com or 630-887-5278

The Versatile VSP2 – Still Cooking After 26 Years


Topics: hazard identification, process safety, process hazards analysis, relief venting, vent sizing, process hazards, chemical engineering safety, runaway reactions, reactive hazard, VSP2, DIERS, chemical reaction, adiabatic calorimetry, relief system design


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