Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Gases and Compressed Air

Air, LNG, LPG and other common gas properties, pipeline capacities, sizing of relief valves

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Compression Ratio - Compressed Air vs. Free Air

The compression ratio is the ratio pressure of compressed air to pressure of free air

Air - Altitude, Density and Specific Volume

Density and the specific volume of air vary with elevation above sea level

Air - Composition and Molecular Weight

Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts

Air - Density at varying pressure and constant temperatures

Figures and tables showing changes in air density at pressure varying from 1 to 10 000 bara (14.5 - 145000 psi) and constant, selected temperatures. Figures are given in different scales.

Air - Density, Specific Weight and Thermal Expansion Coefficient at Varying Temperature and Constant Pressures

Online calculator, figures and tables showing density, specific weight and thermal expansion coefficient of air at temperatures ranging -100 to 1600 °C (-140 to 2900 °F) at atmospheric and higher pressure - Imperial and SI Units

Air - Diffusion Coefficients of Gases in Excess of Air

Diffusion coefficients, D12, for gases in large excess of air at temperature varying from 0 - 400 °C

Air - Dynamic and Kinematic Viscosity

Online calculator, figures and tables showing dynamic (absolute) and kinematic viscosity of air at temperatures ranging from -100 to 1600°C (-150 to 2900°F) at pressure ranging from 1 to 10 000 bara (14.5 - 145000 psia) - SI and Imperial Units

Air - Molecular Weight and Composition

Dry air is a mixture of gases where the average molecular weight (or molar mass) can be calculated by adding the weight of each component

Air - Prandtl Number

Figures and table showing changes in Prandtl number for air with changes in temperature and pressure

Air - Properties at Gas-Liquid Equilibrium Conditions

Figures and tables showing how the properties of air changes along the boiling and condensation curves (temperature and pressure between triple point and critical point conditions). An air phase diagram are also given.

Air - Specific Heat at Constant Pressure and Varying Temperature

Online calculator, figures and tables showing how specific heat (Cp and Cv) of dry air vary with temperature at different pressures, SI and imperial units

Air - Specific Heat at Constant Temperature and Varying Pressure

Figures and table showing isobaric (Cp) and isochoric (Cv) specific heat of air at constant temperature and varying pressure ranging 0.01 to 10000 bara

Air - Thermal Conductivity

Online calculator, figures and tables showing air thermal conductivity at varying temperature and pressure, SI and imperial units.

Air - Thermal Diffusivity

Figures and tables showing dry air thermal diffusivity at varying temperarure and pressure, SI and Imperial units

Air - Thermophysical Properties

Thermal properties of air - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusicity, and more

Air - Volume vs. Temperature

Air volume vs. temperature correction factor compared to Normal Air Conditions

Air Compressor Power Cost per Year

Yearly power cost for operating an air compressor

Air Compressors - Maximum Air Flow at Inlet Pipes

Inlet pipe size and maximum air flow

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Air Discharge through Hoses

Discharging air volume through hoses at pressures ranging 30 - 90 psi

Air Properties - Imperial Units

Thermodynamic properties of air at low pressures - imperial units

Air Specific Heat Ratio

Specific Heat Ratio of air at temperatures from -40 - 1000oC (-40 - 1500oF) at standard atmospheric pressure - Imperial and SI Units

Air Tools and Air Consumption

Average air volume requirement

Ammonia - Density at Varying Temperature and Pressure

Online calculator, figures and tables showing density and specific weight of ammonia at temperatures ranging -50 to 425 °C (-50 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units

ASTM B819 - Seamless Copper Tube for Medical Gas Systems - Dimensions

Copper tube dimensions used for medical gases

Boyle's Law (Mariotte's Law)

Perfect gas and Boyle's law

Charles' Law

A perfect gas - volume and temperature

Classification of Gases

Oxidizers, Inert and Flammable gases

Compressed Air - Air Flow and Recommended Pipe Size

Pipe line sizing compressed air

Compressed Air - Glossary of Terms

A glossary of terms commonly used for compressed air

Compressed Air - Hose Friction Loss

Pressure loss in air hoses at various pressure

Compressed Air - Laboratory Consumption

Required supply of compressed air to laboratories

Compressed Air - Pipe Line Pressure Loss - Online Calculator with Metric and Imperial Units

Calculate pressure drop in compressed air pipe lines - metric and imperial units

Compressed Air - Pipeline Pressure Drop Diagram

Pressure drop in compressed air pipe lines - nomograph diagram

Compressed Air - Recommended Size Pipe Line

Air pipe lines at pressure 100 psi

Compressed Air Pipe Line Capacity

Capacities of compressed air pipelines - applied pressure ranging 5 - 250 psi (0.5 - 17 bar)

Compressed Air Pipe Lines - Pressure Loss

Pressure drop in compressed air pipe lines

Compressed Air Pipes - Fittings and Pressure Drops

Fittings in compressed air pipe lines - equivalent length pressure drop

Compressed Air Piping and Pressure Drop Diagrams - Imperial Units

Pressure drop in compressed air pipelines - applied pressure 50, 100 and 150 psi

Compressed Air Pressure Drop Diagrams - Metric Units

Pressure drop in compressed air pipe lines

Compressed Air Quality

Compressed air is used for power tools, instrumentation, processing and for breathing

Compressed Air Receivers

Calculating air receivers

Compressed Air Water Content

Saturation pressure and maximum water content in compressed air

Compressed Gas or Air - Storage Volume

Calculate the storage volume of compressed gas or air

Control Valve Sizing Calculator - Gases

An online control valve - Cv - calculator for gases

Critical Temperatures and Pressures for some Common Substances

Critical temperatures and pressures for some common substances - air, alcohol, ether, oxygen and more

Dalton's Law

Gibbs'-Dalton's law of partial pressure

Density of Moist Humid Air

Density of dry air and water vapor - moist or humid air

EN 1057 - Copper tubes for water and gas in sanitary and heating applications - Dimensions

Dimensions of EN 1057 Copper and copper alloys - Seamless, round copper tubes for water and gas in sanitary and heating applications

EN 12735 - Seamless, round copper tubes for air conditioning and refrigeration - Dimensions

Seamless, round copper tubes for air conditioning and refrigeration piping systems

EN 13348 - Seamless, round copper tubes for medical gases or vacuum - Dimensions

Copper and copper alloys. Seamless, round copper tubes for medical gases or vacuum

Gas Data

Online database with gas properties

Gas Densities

Densities and molecular weights of some common gases - acetylene, air, methane, nitrogen, oxygen and others ..

Gas Marks - Cookers and Temperature

Gas marks on gas ovens and the heat or temperature developed

Gas Mixture Properties

Special care must be taken for gas mixtures when using the ideal gas law, calculating the mass, the individual gas constant or the density

Gas Pipes - Approved Materials

Materials approved for gas pipes

Gas Vent Termination - Clearance Tolerances

Clearance tolerance per roof slope for gas vent terminations - vent caps

Gases - Explosion and Flammability Concentration Limits

Flame and explosion limits for gases - propane, methane, butane, acetylene and more

Gases - Specific Gravities

Specific gravity of air, ammonia, butadiene, carbon dioxide, carbon monoxide and some other common gases

Horsepower required to Compress Air

Online air compressor horsepower calculator

House Gas Pipe Capacity

Carrying capacity of house gas pipes - in imperial and metric units

Ideal Gas Law

The relations between volume, pressure, temperature and quantity of a gas, including definition of density of a gas

Ideal Properties of Carbon Dioxide Gas

Enthalpy, Entropy and Internal Energy of Carbon Dioxide gas

Liquefied Natural Gas - LNG

LNG or Liquefied Natural Gas

Liquefied Petroleum Gas - LPG

LPG or Liquefied Petroleum Gas

Low Pressure Gas Pipe Sizing

Apartments gas pipe service lines

LP Gas Properties

Liquefied Petroleum - LP - gas properties

LPG Tanks - Required Relief Valve Capacities

Required capacities of relief valves on LPG vaporizers and tanks

Medical Gas Piping

Piping systems for medical gases

Methane - Convert between Liquid and Gaseous Units

Convert between liquid and gaseous unit for LNG or Methane

Natural Gas - Low Pressure Pipe Sizing

Sizing low pressure natural gas pipe lines - imperial units

Natural Gas - Low Pressure Pipe Sizing

Sizing low pressure natural gas pipe lines - Metric values

Natural Gas - Pipe Sizing

Sizing pipes for natural gas - pressures above 5 psi (35 kPa)

Natural Gas - Pipe Sizing Calculator

Calculate the capacities and dimensions of natural gas pipe lines

Natural Gas Consumption

Natural gas consumption for common equipment - like boiling pans, ovens, cookers, kettles and more

Natural Gas Consumption - Laboratory Diversity

Use of natural gas in laboratory outlets

Natural Gas Consumption in Multiple Apartments

Multiple apartments and natural gas diversity and demand

Natural Gas Glossary

Natural gas is used extensively in residential, commercial and industrial applications

Natural Gas Meters - Capacities

Different types of natural gas meters and their capacities

Natural Gas Pipes and Minimum Cover

Burial dept and minimum cover of underground natural gas pipes

Nitrogen - Enthalpy, Internal Energy and Entropy

Enthalpy, internal energy and entropy of Nitrogen as ideal gas

Non-ideal gas - Van der Waal's Equation and Constants

Listing of van der Waals constants for more than 200 gases, used to correct for non-ideal behavior of gases caused by intermolecular forces and the volume occupied by the gas particles

Orifices - Air Discharge

Discharging air volume through nozzles

Orifices - Capacities with Natural Gas

Natural gas capacities for orifices

Oxygen - Enthalpy, Internal Energy and Entropy

Enthalpy, internal energy and entropy of oxygen as ideal gas

Pascal's Law and Hydraulic Force

Pascal's laws relates to pressures in fluids

Pneumatic Cylinder Velocity

Calculating pneumatic cylinder velocity

Pneumatic Cylinders - Force Exerted

Pneumatic air cylinders - air pressure and force exerted calculator


Introduction to pressure - psi and Pa - online pressure units converter

Pressure Converter

Convert from kPa to psi and inches of Water and Mercury

Propane - Latent Heat of Vaporization

Latent heat when propane vaporize

Propane Air Mixture

Energy content and specific gravity of propane air mixtures

Propane Butane Mixture - Evaporation Pressure

Evaporation pressure of propane butane mixtures

Propane Gas Pipe Sizing

Sizing low pressure propane gas pipe lines - Imperial units

Propane Gas Pipe Sizing

Sizing propane gas pipe lines - for pressures above 5 psig (35 kPa)

Pumps, Compressors, Blowers and Fans

Comparing pumps, compressors, blowers and fans

Rating of Air Compressors and Air Equipment

Common terms rating air flow capacity are ICFM, FAD, ANR, SCFM or nl/min

Relief Valves - Length of Vent Lines

Calculating length of safety valves vent pipes

Safety Relief Valve Capacities

Maximum free air relief capacity of safety valves

Safety Valves in Gas and Vapor Systems

Calculate relief valves in gas and vapor systems

SCFM versus ACFM and ICFM

Actual air compressor capacity (ACFM) versus standard air capacity (SCFM) and inlet air capacity (ICFM)

Single Acting Pneumatic Pistons - Air Consumption

Air volume used by single-acting pistons

Sizing Propane Gas Pipe Lines

Sizing low pressure propane gas pipe lines - Metric units

Speed of Sound in Air

Speed of sound in air at temperatures from -40 to 1000oC (-40 to 1500oF) at standard atmospheric pressure - Imperial and SI Units

Steam and Vapor Enthalpy

Introduction and definition of vapor and steam enthalpy - specific enthalpy of saturated liquid, saturated vapor and superheated vapor

Types of Air Compressors

Reciprocating, rotary screw and rotary centrifugal air compressors

Universal and Individual Gas Constants

The Universal and Individual Gas Constants in fluid mechanics and thermodynamics. Individual gas constant is given for the most common gases.


Vacuum is defined as air pressure below atmospheric pressure

Vacuum - Evacuation Time

Vacuum pumps - calculating flow rate and required evacuation time

Vacuum - Expansion Air Ratio

Convert vacuum air volume to standard air volume

Vacuum and Measurement of Flow

Measuring volume flow in vacuum

Vacuum Pipe Lines - Pressure Drops

Vacuum pipes and pressure drops

Vacuum Pipes - Velocities

Vacuum pipes - air velocity diagrams

Vacuum Pressure - Units Converter

Vacuum converting units - % vacuum - mm Mercury - psi - torr - micron - kPa

Vacuum Pumps - Exhaust Pipes

Capacities of vacuum pump exhaust pipes

Vapor and Steam

Introduction to vapor and steam

Vapor Pressures common Liquids

Vapor and saturation pressure for some common liquids

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