hydraulic systems

hydraulic operations are roughly ________ efficient, with ______ loss due to fluid friction

100

negligible

the 3 principles categories of hydraulic fluids are: __________,__________, and ________ base

mineral base, polyalphaolefin base, phosphate ester

phosphate ester based fluids are used mostly in transport category aircraft which is commonly referred to as _______________. Presently, type __________ and ____________ are used exclusively

Skydrol

IV

V

hydraulic systems require special accessories such as _____________, ___________ and __________ to be compatible with the fluid being used

seals

gaskets

hoses

filter rating are given in terms of __________, and is an indication of the ________ size that will be filtered out

micron

particles

differential pressure indicators are designed to prevent false indications due to ___________, __________ or ___________

cold start

pump ripples

shock loads

power packs are driven by wither an ________________ or ______________

engine gearbox

electric motor

reservoirs can be pressurized or ___________. commercial transport aircraft have pressurized reservoirs and most of them use ______________ to do this

non-pressurized

bleed air

a filter is a(n) ___________, or ____________ device used to clean hydraulic fluid, thus ____________ foreign contaminates from remaining in the system

screening

straining

preventing

maintenance of filters is relatively easy. It consist mostly of ____________ the filter and element or cleaning the filter and __________ the element

cleaning

replacing

____________ pressure provides a convenient means of monitoring the condition of installed filter elements. it is the __________ used in the differential -pressure or ___________- filter indicators found on many filter assemblies

differential

operating principle

loaded

once extended, the differential pressure indicators must be ___________ and provides a __________ warning of a loaded element

manually reset

permanent

all aircraft hydraulic systems have one or more _________ pumps and may have a _________ pump as an additional unit when the _________ pump is inoperative

power-driven

hand

engine driven

pumps may be classified in 1 of 2 categories: __________ or ___________ displacement

positive, non-positive

the _________ section of the drive coupling, located __________ of the two sets of spline, is __________ in diameter than the spines

shear

in the middle of

smaller

most values are __________ controlled by a _________ and are sometimes called ________ valves

electrically

servo

servo

a sequence valve _________ fluid to a second actuator or motor after a set ________ has been reached, to do work in another part of the system

diverts

pressure

a ____________ valve will give precedence to the critical hydraulic sub systems over __________ systems when system pressure is __________

priority

non-critical

low

fuses detect sudden increase in flow such as a ___________ downstream, which in turn, ___________ hydraulic fluid for the rest of the system

burst

preserves

pressure relief valves are necessary to prevent _________ of components or ______________ of hydraulic lines under __________ pressure

failure

rupture

excessive

____________ relief valves are used to relieve excessive pressure that may exist due to ________ of the fluid

thermal

thermal expansion

pressure _____________ are devices used to manage the output of the ___________ to maintain operating system pressure within a fixed ranged

regulators

pump

the main purpose of the ________ valve is to isolate the normal system from an alternate or emergency system. the sliding component of this valve is to __________ either one of the other inlets ports

shuttle

seal off

shut off valves are used to shut off the flow of fluid to a particular __________ or _________

system

components

the initial charge of an operational accumulator is know as ____________

preload