Ayvaz — since 1948
FlowLab
Free engineering calculations for steam and condensate systems.
No sign-in required. Every calculation names the standard it rests on, and carries a case verified against the reference values published in that standard.
Did you know?
At 1.013 bar, 1 kg of water becomes 1,604 times its volume as steam — one litre of water makes 1,674 litres of steam.
Fluid properties & tables
Saturated Steam Table — by Pressure
Saturation temperature, enthalpy, entropy and specific volume at a given pressure.
Saturated Steam Table — by Temperature
Pressure, enthalpy, entropy and specific volume at a given saturation temperature.
Superheated Steam Table — by Pressure and Temperature
Enthalpy, entropy, specific volume and specific heat of superheated steam. Below the saturation line it returns compressed-water properties.
Piping: loss, velocity, size
Pressure Loss & Velocity in Piping
Friction loss, velocity, Reynolds number and regime at a given size and flow, for five fluids.
Pipe Sizing — by Pressure Loss and Velocity
The smallest standard size that satisfies both the allowable pressure loss and the velocity limit, and which criterion governs.
Flow Rate in Piping — from Pressure Loss
The flow a line passes for a measured or allowed pressure loss, and the velocity at that flow.
Condensate Line Sizing — Two-Phase Flow
Pipe size for a trap discharge, a common return header or a pumped line — with the flash steam counted in.
Vent Pipe Sizing
The vent of a flash vessel, condensate receiver or deaerator — checked on velocity and on the back pressure it creates.
Leak Rate Through a Hole
The steam, water, air or gas escaping through a hole, crack or orifice — and what it costs in a year.
Pressure Drop Analysis — Element Chain
Seven fluids and sixty-four pipe elements; Δp along the line by chaining bends, valves and strainers.
Valves, orifices, relief
Cv & Kvs Values
The valve capacity needed to pass a required flow at a given pressure drop.
Flow Rate through a Valve
The flow a valve of known Kv or Cv passes at a given pressure drop.
Safety Relief Valve Sizing
Required orifice area and bore from the relieving capacity, set pressure and overpressure.
Pressure Reducing Station
The Kv of the reducing valve, and the capacity the downstream safety valve must pass if the reducer fails open.
Desuperheating — Injection Water
The water to inject to bring superheated steam down to a target temperature, and the resulting flow.
Heat load & condensate generation
Pipe Heat Loss & Surface Temperature
Heat loss per metre from an insulated or bare pipe, and the surface temperature for touch safety.
Economic Insulation Thickness
The insulation thickness that minimises total cost for your energy and material prices, with its payback.
Heat Exchanger — LMTD & Surface Area
The duty of a steam-heated stream, its log mean temperature difference, the area needed and the steam consumed.
Uninsulated Valve & Flange Loss
The annual heat and fuel lost through uninsulated fittings, compared with fitting a jacket.
Condensate from Compressed Air
The water dropping out after the compressor and aftercooler, the dew point, and the cooler’s latent load.
Moist Air Properties
Absolute humidity, dew point, wet-bulb temperature, enthalpy and density from temperature and relative humidity.
Condensate drainage & recovery
Flash Steam Generation
The flash steam formed when condensate drops to a lower pressure, its fraction and the volume increase.
Condensate Recovery Economics
The annual value of recovering condensate across energy, water, chemicals and blowdown.
Steam Main — Start-up and Running Load
The condensate capacity needed to warm a cold steam main, and the running load once it is up to temperature.
Continuous Flow Heating — Condensate Load
The steam demand and trap capacity for heating a liquid flowing continuously through an exchanger.
Batch Tank Heating — Condensate Load
The steam needed to bring a tank batch up to temperature — heat-up and hold loads given separately.
Air Heater — Condensate Load
The steam demand, condensate load and trap capacity of a steam-to-air coil.
Stall Point
The operating point where a control-valved exchanger can no longer drain its condensate unaided.
Steam quality
Improved Dryness by Pressure Reduction
Dryness after throttling; give a separator efficiency and the dryness after separation follows.
Dryness Measurement — Throttling Calorimeter
The true dryness of the line steam from the pressure and temperature measured in the calorimeter.
Air Mixed in Steam — Temperature Drop
Given the air fraction, the real steam temperature and the degrees lost against pure steam.
Air Mixed in Steam — Air Fraction from Measurement
The air fraction in the line from the measured pressure and temperature. If pressure and temperature disagree, the difference is air.
Boiler house
Blowdown Rate & Feedwater
The blowdown needed to hold the boiler TDS limit, the feedwater flow, and the heat going down the drain.
Blowdown Heat Recovery
The steam recovered by flashing the blowdown, the heat recovered in the exchanger, and what is left.
Deaerator Steam Consumption
The steam spent bringing feedwater to deaerator temperature, and its share of the boiler load.
Boiler Efficiency — from Flue Gas Losses
Boiler efficiency by the indirect method from flue gas temperature and oxygen, with the loss breakdown.
Energy, cost, investment
Pipe mechanics & support
Thermal Expansion & Expansion Joint Movement
How far the line grows, the movement asked of the expansion joint, and the stroke needed with cold pull.
Expansion Joint Reaction & Anchor Load
The total load an anchor sees from pressure thrust and spring force, and what a tied joint changes.
Flexible Metal Hose — Length & Bend Radius
The shortest live length for a given lateral movement, the minimum bend radius, and installation warnings.
Pipe Support Span & Weight
The largest support span allowed by stress and by deflection, the load per support, and the pipe weight.
Pipe Wall Thickness & Pressure Class
The wall thickness needed for internal pressure, the ordering thickness with corrosion and mill tolerance, and the flange pressure class that fits.
Water Hammer — Joukowsky
The pressure surge on valve closure, the wave speed, and the effect of closing time.
