SepRate: sizes both vertical and horizontal two-phase oil-gas separators, three-phase water-oil-gas separators, free-water knockout drums (FWKO) and flare knockout drums (KOD). Also calculates the capacity of existing vessels ("Rating Mode”). Calculation is based on API SPEC 12J and API RP 521.
CompPower: calculates the required brake power of multistage reciprocating compressors based on the guidelines available on the GPSA Engineering Data Book.
PumpPower: calculates the required shaft power of centrifugal pumps.
VesselSize: sizes vertical/horizontal pressure vessels and estimates the minimum required wall thickness (based on ASME Code, Section VIII, Div. 1) and the weight of the vessel (full and empty).
ExpSize: calculates the volume change a liquid undergoes due to thermal expansion. The volume required by an expansion vessel may be calculated, which is in particular useful when designing heat transfer circuits based on hot-oil circulation.

Piping sizing tools
GasDrop: calculates the inlet pressure, the outlet pressure or the flow rate for compressible flow (gas lines) based on any of the following equations: Weymouth, AGA fully turbulent, Panhandle A, Panhandle B, Oliphant, Spitzglass, and ideal gas equation (isothermal). The module features a built-in list of fittings (such as valves, elbows, etc.) and piping materials’ roughness.
LiqDrop: calculates the inlet pressure, the outlet pressure, required diameter, or the flow rate for incompresible flow (liquid lines). The module features a built-in list of fittings (such as valves, elbows, etc.) and piping materials’ roughness.
TwoSize: sizes two-phase gas-liquid lines, i.e. internal diameter, based on API RP 14E (5th Ed).
PumpNPSH: calculates the available Net Positive Suction Head (NPSH) for centrifugal and reciprocating pump installations.
HeaderRate: estimates the capacity of a flare header using the ideal gas equation.
GasValve: calculates the flow coefficient (CV) of a gas control valve.
LiqValve: calculates the flow coefficient (CV) of a liquid control valve.

Pressure-relieving devices sizing tools
GasPSV: calculates the required orifice of a pressure safety valve (PSV) for gas relief based on API RP 520 Part I (7th Ed)
LiqPSV: calculates the required orifice of a pressure relief valve (PRV) for liquid relief based on API RP 520 Part I (7th Ed)
SteamPSV: calculates the required orifice of a pressure safety valve (PSV) for steam relief based on API RP 520 Part I (7th Ed)

Last but not least, some handy tools
Unit Converter: convert between the most usual units found in the O&G industry.
Interpolator: given two points, extrapolate a third one (linear).
Steam Table: given a pressure, calculate the saturation steam temperature, and vice-versa.
Typical Piping: browse through a typical steel piping class used for general hydrocarbon service (internal/external diameter, MAWP and Schedule). You can also obtain the internal diameter of a pipe by entering directly its nominal diameter/schedule.