Some more hydraulic terms you may want to understand what they mean.

Kinematic viscosity – it is a fluid’s viscosity that is divided by it’s density.

Lapping – you take lapping compound on a lapping machine, lay your part on there and it will take out the smears, cut marks and put a smooth finish your metal parts.

NAS – if you see this abbreviation on a container it means, national aerospace standard.

NFPA – this abbreviation means national fluid power association.

OEM – means original equipment manufacture.

Orifice – restricts fluid flow and it is small in size.

PPM – parts per million.

PV – this abbreviation means pump, a variable displacement.

Relief Valve – a mechanism that takes away pump flow to the reservoir tank when the level you set it at is reached. That way you don’t have to watch it all the time if you set it at a certain level.

Rotating Group – this is a complete set of a cylinder block (barrel), pistons (numbers vary in the amount), retaining ring, springs, ball guide for a pump or motor. You can order these separate most of the time. But as a complete set it may be cheaper that way.

SAE – this means Society of Automotive Engineers. Usually if they recommend a certain part or fluid, it runs best for that particular machine.

Silt – particles that are less than 5 microns that are very fine and not soluble in your fluid.

Vapor pressure – when the liquid and gases of a fluid are in balance at any given temperature.

VG – density grade of a hydraulic fluid.

These are just a few of the hydraulic words you may or may not know the meaning to. Comes in handy if you need to understand a repair person of a hydraulic shop.

If you need help with any of this, call us at 800-361-0068

sales@hydrostatic-transmission.com