Hydraulics, Pneumatics, and Industrial Maintenance Flashcards

A comprehensive set of vocabulary flashcards covering hydraulics, pneumatics, pump maintenance, pipefitting, and equipment alignment based on technical lecture notes.

Maximum Hydraulic Pressure

Typically around $3000\,psi$ in standard hydraulic systems.

Bottle Jack Bypass Vanes

Threads that allow fluid to bypass back into the reservoir if a bottle jack is stroked out while being pumped.

Incompressible Factor of Liquids

Negligible compression of about $0.5\%$ for every $1000\,psi$.

Flow

The volume of fluid being pumped, measured in GPM (Gallons Per Minute) or LPM (Liters Per Minute).

Velocity

The distance travelled by a fluid over time, measured in inches per second or minute.

Turbulent Flow

Flow characterized by friction in lines that creates heat and results in pressure drop.

Force Formula (Hydraulics)

$$Force = Pressure \times Area$$

Surface Area of a Cylinder

$$\pi \times \text{radius}^2$$

First Class Lever

A lever where the fulcrum is located between the effort and the load ($\text{effort} \text{---} \text{fulcrum} \text{---} \text{load}$).

Mechanical Advantage (MA)

The ratio of the effort arm (EA) to the load arm (LA), calculated as $MA = EA / LA$.

Metering Out Circuit

Putting a flow control valve on the outlet of a cylinder to control flow; it may cause pressure intensification.

Pressure Compensated Restrictor

A valve that maintains constant flow despite workload changes by auto-compensating for pressure changes.

Relief Valve

A pressure control valve that limits maximum system pressure and is typically normally closed.

Cracking Pressure

The pressure at which a valve poppet first starts to lift and divert flow.

Pressure Override

The difference between cracking pressure and full flow pressure.

Sequence Valve

A valve that actuates at a setpoint to divert flow to a secondary part of the system, often used in clamp and drill setups.

Brake Valve

A valve frequently used with hydraulic motors for dynamic braking, often featuring an $8:1$ ratio pilot piston.

Closed Centre DCV

A Direction Control Valve that traps flow in parts of the circuit to stop and hold a load.

Regenerative Centre

A DCV centre used for fast extension where the area around the rod is equalized.

Dash Number (Hose Sizing)

Hose sizing increments of $1/16^{th}$ of an inch (e.g., -8 = $1/2"\,ID$).

Pascal's Law

Pressure applied to a confined fluid is transmitted equally in all directions and at right angles to the surface.

Viscosity Index

A measure of how much a fluid's viscosity changes with temperature; higher numbers indicate less change.

NPT (National Pipe Thread)

A thread with a taper of $3/4"$ per foot that requires sealant due to a spiral leak path.

NPTF (National Pipe Thread Fuel)

A dry seal thread common in hydraulics that provides $100\%$ engagement on the sides, crest, and root.

JIC (Joint Industry Council)

A hydraulic fitting with a $37$ degree flare.

Differential Cylinder

The most common cylinder type where the cap side and rod side have different volumes and surface areas.

Rod Wiper

A seal component that protects the rod seal from external contaminants.

Beta Rating (Filters)

A filter efficiency ratio calculated by dividing upstream particles by downstream particles.

Total Indicator Reading (TIR)

The full value shown on a dial indicator; half of this value is used for alignment calculations.

Soft Foot

An alignment condition where machine feet do not sit flat, categorized as angular, sprung, or ordinary.

Thermal Coefficient of Steel

$$0.0000063$$

Fitting Allowance

The measurement from the center of a fitting to the point where the threads begin.

Globe Valve

A valve used for throttling fluid that creates significant pressure drop through a disk pressing against a seat.

SWP / WSP

Standard ratings for steam valves, standing for Steam Working Pressure or Working Steam Pressure.

Coalescing Filter

A filter where tiny water molecules come together to form drops, providing a self-cleaning action for moisture removal.

FRL

A common pneumatic component assembly consisting of a Filter, Regulator, and Lubricator.

Net Positive Suction Head (NPSH)

The dynamic positive suction head calculated as static suction head minus velocity head and friction losses.

Volute

A specialized pump casing designed to convert fluid velocity into pressure.

Wear Rings

Replaceable parts that maintain small clearances between the pump impeller and casing to protect against abrasive damage.

Stuffing Box

A chamber in a pump designed to house mechanical packing or a mechanical seal to prevent leakage.

Steady Bearing

A support bearing used to stabilize vertical shafts in turbine pumps.

Progressive Cavity Pump

Another name for a screw pump, which is a type of positive displacement pump.