 # Calculators

Online calculations of hydraulic system

## Temperature-Viscosity Chart

The interpolation calculator provided below is used to determine:

• the kinematic viscosity values, depends from temperature, calculated by the formulas specified in ASTM D341 – (‘Standard Practice for Viscosity-Temperature Charts for Liquid Petroleum Products’);
• the Viscosity Index (VI) by the formulas specified in ASTM D2270 (Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100°C 1) or in ISO 2909 (Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 and 100°C 1) or in ГОСТ 25371-2018 (Нефтепродукты. Расчёт индекса вязкости по кинематической вязкости)

#### Annotation.

Any mineral oil is supplied with the specification of kinematic viscosity values at two different temperatures, usually at 40°C and at 100°C (or at 100°F and at 210°F). These data is enough to determine kinematic viscosity at any other values of temperature and as well Viscosity Index.

You can calculate pre-filled values of oil classified by ISO 3448 with grades VG22, VG32, VG46 or VG68 (at viscosity Index = 100) or enter specific values for any other oils.

## Orifice flow calculation Calculation flow trough orifice

Here is an online calculator of the flow through the orifice. Using this chart you can determine both flow through existing orifice or estimate the orifice diameter for required flow.

## Pump-Motor calculation Pump-Motor calculations

Here you can find the online calculations for Pump-Motor in close loop.
These calculations are for variable displacement pump and fixed displacement motor.

## Conduit calculations (pressure losses, velocity) Pressure losses in the conduit

These calculations can help you to estimate the pressure losses, and flow velocity in the conduit (hose, pipe or tube) and check/correct conduit ID.

Calculations Notes:

• The recommended flow velocity in conduits you can find at the article Recommended flow velocity.
• The assumption: pressure losses on elbows, fittings at calculated conduit is zero.
• Height difference between IN and OUT points needs to calculate hydrostatic pressure what will be added to pressure losses, if IN point is below OUT (use positive value), or subtracted from pressure losses, if IN point is upper than OUT (use negative value). Use value “0” if height difference can be neglected.
• To find Darcy friction factor there are different formulas used: