FM 5-499 FM 5 -499
F i el d M a n u a l
H ea d q u a r t er s
N o. 5 -4 9 9
D e p a r t m e n t of t h e Ar m y Washington, DC, 1 August 1997
Hydraulics T a b l e o f Co Co n t e n t s Page LIST OF FIGURES AND TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
F igur es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii Ta bles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii P R E F A C E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv C H AP AP T ER E R 1 . H y d ra ra u l ic i c B a s ic i c s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1-1. 11. Pr essu re a nd F orce. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1-1 P r ess u r e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 F orce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 -3 1-2. Pa scal’ scal’ss La w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4 1-4 1-3. Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Velocity Velo city . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 F low Rat e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 -6 1-4. 14. En ergy, Work Work , an d P ower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Pot en t ial E ner gy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 1-6 Kin et ic En er gy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Hea t En er gy an d F r ic ictt io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6 Relat io ions ns h ip Betw een Velo Veloci citt y an d P r essu re . . . . . . . . . . . . . . . . . . . . . . . . 1-7 Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8 P ower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 -8 C H AP AP T ER ER 2 .
H y d ra ra u l ic ic S y s te t e m s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2-1. Bas ic Syst em s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 2-1 Hyd ra ulic J ack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Motor-Reversing System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1 Open -Cen t er Syst em . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 Closed-Cen Clo sed-Cen te r Syst em . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
DISTRIBUTION RESTRICTION: Approved fo for pu bli blicc release; release; distribut io ion n is un limited.
FM 5-499 Page
2-2. Color Color Coding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 2-3. Reser vo voirs irs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 Cons t r u ction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9 Sh a pe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 Locaa t ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 Loc Vent ilat io ion n a n d P re ssu r izat io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 Line Conn ections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 Ma int ena nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-11 2-4. 24. Str ainer s a nd F ilter s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-11 11 St r a iner s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12 F ilt er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12 2-5. 25. Filtering Mat erial and Element s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-14 .2-14 2-6. Ac Accum cum ula t ors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 Spr ing-Lo ing-Loaa ded Accum Accum ula t or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 Ba gg-Type Type Accum Accum ula t or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 Pis ton -Ty -Type pe Accumu Accumu lat or . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 Ma int ena nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 2-7. 27. Pr essu re Ga uges an d Vo Volum e Meter s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-17 Pr ess ur e Ga uges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 Met er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 2-8. 28. Port able H ydrau li licc-C -Circuit ircuit Test ers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-18 18 Test er s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 Im pr oper Op er at io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 2-9. 29. Circulat or y System s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-18 Tu bin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 P ipin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 F lexibl lexiblee H osing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 In st alla t io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21 2-10. Fit t ings a nd Connect ors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-21 Th re ade d Conn ectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22-21 21 F lar ed Conn ectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 F lexible-Hose C ouplin gs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 Reus able F itt ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 2-11.L ea ka ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 In te rn al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 E xt er n a l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 P re vent io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 2-12. Sea ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-30 St a t ic Seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31 Dyna mic Sea ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31 P a ckin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 Sea l Ma t er ials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
FM 5-499 Page C H AP AP TE T E R 3. 3.
P u mp m p s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3-1. P um p Clas sific sificat at ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3-1 Nonp osi ositt iveive-Displa Displa cemen t P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 3-1 Posit iveive-Displa Displa cemen t Pu mp s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 Cha r act eris t ic icss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 3-2. Per fo forr ma nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 3-2 3-3. Displa cemen t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2 3-2 Fixed-Displa cemen t P um p. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 3-3 Var iable-Displaceme nt P um p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 3-3 3-4. Slippa ge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 3-3 3-5. Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Cent r if ifuga uga l P u mp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3 Rota r y P u m p. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 Reciprocat Reciproc at ing P um p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 3-6. Gear P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 E xt er n al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 In t er n al . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 Lobe P um p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 3-7. Vane Pu mp s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 3-6 Cha r act eris t ic icss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 Un bala nced Van e P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 Bala nced Van e P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 Double P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 Two-St TwoSt a ge P u m ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9 3-8. Pis t on P um ps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 3-10 Ra dia l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 Axial Axi al Pis ton Pu mp s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 3-9. 39. Pu mp Opera tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 3-14 Over loadin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 E xcess S pee d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 Ca vit at ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14 Oper at ing P roblem s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15 C H AP AP T ER ER 4 .
H y d ra ra u li l i c Ac Ac t u a to to rs r s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4-1. Cylinder s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Sin gle-Ac gle-Actt in g Cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Double -A -Actin ctin g Cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Differ Diff er en t ial C ylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 Nondifferential Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Ra m -Type Cylin der . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 Pis t on-Type Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 Cus h ioned Cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 Lockou Loc kou t Cylin der s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 4.2 Co Const nst ru ction an d Applic Applicat at io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
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4-3. Ma int en an ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Ext er na l Leak a ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 In te rn al Lea ka ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Cr eeping Cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Slu ggi ggish sh Oper at io ion n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Loose Loo se M ount ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 Misa lignme nt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5 La ck of Lu br icat ion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7 Abra sives on a P ist on Rod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7 Bur rs on a Pis t on Rod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7 Air Ven t s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7 4-4. 44. Hydr au lic Mo Mott ors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44-7 7 Gear -Type Mot ors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 Van e-Type M otor s. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 P ist on-Type M otors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10 C H AP AP TE T E R 5. 5.
V a lv lv e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5-1. 51. Pr essu re-Co re-Cont nt rol Valves Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-1 1 Relief Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2 P re ssu re -Reducing Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 Sequ ence Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5 Count er bala nce Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7 Pr essu re Swit ches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 5-2. Direct ional-Co ional-Cont nt rol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 P oppet Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 Slidin gg-Sp Sp oo ooll Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Ch eck Va lves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 Two-Way Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 F our -Way Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 5-3. FlowFlow-Cont Cont r ol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 Ga t e Va lve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19 Globe Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 N eedle Va lve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 Rest r ictor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 Or ific ificee Ch eck Valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 F lo low w E qua lizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 5-4. Valve Ins t alla tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 Met er -In Circu it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 Met er -Ou t Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 Bleed-Off Circu it . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 Compen sat ed F lo low w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 5-5. 55. Valv Valvee Fa ilures a nd Rem edies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55-26 26 Ser vic vicing ing Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27 Disa ss emblin g Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27 Rep air in g Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
FM 5-499 Page
5-6. Valve Assem bly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 5-7. Tr oublesh oo oott ing Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 Pr essu re -Co -Cont nt rol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 5-30 Direct io iona na ll-Cont Cont r ol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-32 Volum Vo lum e-Cont r ol Va Va lves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-33 C H AP AP T E R 6 .
C i r cu c u i t D ia ia g r a m s a n d T ro ro u b l e s h o o ti t i n g . . . . . . . . . . . . . . . . . . . . . 6-1
6-1. Hydr au lic 6-1. lic-C -Circuit ircuit Diagr am s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1 6-2. 62. United States of Americ merican an St andar ds Institut e (USA (USASI) SI) Graphic Graphical al . . . . . . . 66-1 1 Symbols Res er voir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 Lin es . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 P u m p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 Motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 Cylin der . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 Pr essu re -Co -Cont nt rol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5 6-5 F lowlow-Cont Cont r ol Va Va lves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 Direct io iona na ll-Cont Cont r ol Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 Accessor Ac cessor ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9 6-3. Typic Typical al M obil obilee Cir cuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 Hyd ra uliculic-Lif Liftt Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 Power -Steer ing Cir cuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 Road-Pa t r ol ol-Tru -Tru ck Circuit s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 6-4. Tr oublesh oo oott ing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 Ca use s of Impr oper O per at io ions ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 6-13 Test ing a H ydr au lic Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 6-13 Compa r ing Test Resu lt s wit h S peci pecific ficat at ions . . . . . . . . . . . . . . . . . . . . . . . 6-13 6-13 Slipp a ge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 Flow a n d P re ssu r e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 6-15 Ot her Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15 Specific Specif ic Troubles, Ca use s, a nd Solut io ions ns . . . . . . . . . . . . . . . . . . . . . . . . . . 6-16 6-16 C H AP A P T E R 7. 7.
E l e ct c t r ic ic a l D e v i c e s : T ro r o u b l e sh s h o o t i n g a n d S a fe f e t y . . . . . . . . . . . . . . . 7-1
7-1. Hydr au lic 7-1. licss a nd E lec lectr tr ic icity ity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7-2. 72. Troubleshoo Troubleshootin tin g Elect Elect rical Device Devicess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 P r oc ocedu edu r e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 -5 Tes t ing De vices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 7-3. Gr ound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 Ea r t h Gr ound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-8 7-8 Cha ssis or Comm on Gr oun d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9 7-9 Zero Refer en ce Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9 Isolation Between Ea rt h a nd Cha ssis Gr oun d . . . . . . . . . . . . . . . . . . . . . . 77-10 10 7-4. Sa fety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 In fo forr m a t ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-10 P ra ctices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11
FM 5-499 Page A P P E N D I X A . M e tr tr i c Co C o n v e r s i o n C h a r t . . . . . . . . . . . . . . . . . . . . . . . . . . . Appen dix-1 GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Glossa r y-1 R E F E R E N C E S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refer en ces-1 I N D E X . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In dex-1
FM 5-499
Li s t o f F i g u r e s a n d Ta b l e s Figures Page F i g u r e 1 - 1. 1. Basic hydrau lic devic devicee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 F i g u r e 1 -2 -2 .
Compressibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
F i g u r e 1 -3 -3 .
Water col colum um n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
F i g u r e 1 -4 -4 .
Pum p pressure pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
F i g u r e 1 -5 -5 . Inte Interactio raction n of h ydrau lic and atm ospheric pressures pressures . . . . . . . . . . . . . . 1-4 F i g u r e 1 -6 -6 .
Force, Forc e, pressure, an d area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
F i g u r e 1 -7 -7 .
Pascal’ Pasc al’ss L aw apparatu s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-5
F i g u r e 1 -8 -8 .
Lam inar and turbule turbulent nt flow flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
F i g u r e 1 -9 -9 . Effec Effectt of friction friction on pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7 F i g u r e 1 -1 -1 0 . Bernouilli’ Bernouilli’ss Prin ciple . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-8 F i g u r e 1 -1 -1 1 . Com bined effe effects cts of friction friction a nd velo velocity city chan ges . . . . . . . . . . . . . . . . 1-9
F i g u r e 2 -1 -1 . Hydraulic jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2 F i g u r e 2 -2 -2 . Motor-reversing system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 F i g u r e 2 -3 -3 .
Open-center system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
F i g u r e 2 -4 -4 .
Open-center Open-c enter system wit h a series conn conn ec ection tion . . . . . . . . . . . . . . . . . . . . 2-4
F i g u r e 2 -5 -5 .
Open-center Open-c enter system wit h a series/ series/ parallel connectio connection n . . . . . . . . . . . . . 2-5
F i g u r e 2 -6 -6 .
Open-c Ope n-ceenter system system with a flow d ivider . . . . . . . . . . . . . . . . . . . . . . . . 2-6
F i g u r e 2 -7 -7 .
Closed-center system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6
F i g u r e 2 -8 -8 .
Fixed-displacement pump and accumulator . . . . . . . . . . . . . . . . . . . . 2-7
F i g u r e 2 -9 -9 .
Variable-displacement pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
F i g u r e 2 -1 -1 0 . Clo Closedsed-ce center nter system with charging p um p . . . . . . . . . . . . . . . . . . . . . . 2-8 F i g u r e 2 -1 -1 1 . Design features of a reservoir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 F i g u r e 2 -1 -1 2 . Hydraul ic ic--syste system m stainers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-12 F i g u r e 2 -1 -1 3 . Full-f Full-flow low h ydrau lic filter filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13
FM 5-499 Page F i g u r e 2 -1 -1 4 . Propo Proportional-flow rtional-flow filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13 F i g u r e 2 -1 -1 5 . Spring-loaded accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-15 F i g u r e 2 -1 -1 6 . Bag-type accumulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 F i g u r e 2 -1 -1 7 . Pisto Piston-type n-type accum accum ulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-16 F i g u r e 2 -1 -1 8 . Pressure gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 F i g u r e 2 -1 -1 9 . Nu tatin gg-pisto piston-disc n-disc flowm eter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-17 F i g u r e 2 -2 -2 0 . Portable hyd rau liclic-circ circuit uit teste tester r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-18 F i g u r e 2 -2 -2 1 . Me Method thod of installing tubin g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 F i g u r e 2 -2 -2 2 . Flexible rubber hose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20 F i g u r e 2 -2 -2 3 . Installing flexible hose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-20 F i g u r e 2 -2 -2 4 . T hr eaded-pipe connecto connectors rs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-22 F i g u r e 2 -2 -2 5 . Flared-tube connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-23 F i g u r e 2 -2 -2 6 . Flare Flared-tube d-tube fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-24 F i g u r e 2 -2 -2 7 . Field-attachable couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 F i g u r e 2 -2 -2 8 . Ho Hosese-le length ngth m easurem ent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 F i g u r e 2 -2 -2 9 . Hose cutting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-25 F i g u r e 2 -3 -3 0 . Pe Perm rm anently att ache ached d couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26 F i g u r e 2 -3 -3 1 . Skived fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-26 F i g u r e 2 -3 -3 2 . Trimm ing a hose hose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 F i g u r e 2 -3 -3 3 . Fe Fem m ale portion portion of a fitti ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-27 F i g u r e 2 -3 -3 4 . Male an d fem ale portions portions of of a fitti ng . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 F i g u r e 2 -3 -3 5 . Tightening a fitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 F i g u r e 2 -3 -3 6 . N onskived fitti fitting ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 F i g u r e 2 -3 -3 7 . Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-28 F i g u r e 2 -3 -3 8 . Assembly of clamp-type coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-29 F i g u r e 2 -3 -3 9 . S tatic seals seals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31 F i g u r e 2 -4 -4 0 . O-ring placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-31 F i g u r e 2 -4 -4 1 . OO-rin rin g rem oval tool tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 F i g u r e 2 -4 -4 2 . Backup ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-32 F i g u r e 2 -4 -4 3 . T-ring seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 F i g u r e 2 -4 -4 4 . Lip seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33
FM 5-499 Page F i g u r e 2 -4 -4 5 . Cup seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 F i g u r e 2 -4 -4 6 . Pisto Piston n ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-33 F i g u r e 2 -4 -4 7 . Face seal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34 F i g u r e 2 -4 -4 8 . Co Com m pre pressio ssion n packing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-34
F i g u r e 3 -1 -1 . Nonposi Nonpositivetive-displace displacem m ent pu m p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1 F i g u r e 3 -2 -2 . Rec Reciproc iprocatin atin g-type g-type,, positivepositive-di di splace splacem m ent pum p . . . . . . . . . . . . . . . . . 3-2 F i g u r e 3 -3 -3 .
PositivePo sitive-displace displacem m ent pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2
F i g u r e 3 -4 -4 .
Volute Vol ute pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4
F i g u r e 3 -5 -5 . Diffuser pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 F i g u r e 3 -6 -6 . Exte Externa rna l gear gear pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 F i g u r e 3 -7 -7 . Internal gear pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5 F i g u r e 3 -8 -8 . Lo Lobe be pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6 F i g u r e 3 -9 -9 .
Unbalanced Unbalance d vane pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7
F i g u r e 3 -1 -1 0 . Balance Balanced d vane pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7 F i g u r e 3 -1 -1 1 . Van ee-type type double pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8 F i g u r e 3 -1 -1 2 . Fluid flow from from van ee-type type double double pum ps . . . . . . . . . . . . . . . . . . . . . . . 3-8 F i g u r e 3 -1 -1 3 . Van ee-type, type, two-stage two-stage pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9 F i g u r e 3 -1 -1 4 . S im plifi plifieed radial piston piston pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10 F i g u r e 3 -1 -1 5 . Nine-piston radial piston pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 F i g u r e 3 -1 -1 6 . Pintle for a radial piston pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11 F i g u r e 3 -1 -1 7 . Cylinder block block for for a rad ial piston pum p . . . . . . . . . . . . . . . . . . . . . . 3-12 F i g u r e 3 -1 -1 8 . Pisto Pistons ns for a radial piston pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12 F i g u r e 3 -1 -1 9 . In In-line line piston piston pu m p . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13 F i g u r e 3 -2 -2 0 . Bent-axial piston pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-14
F i g u r e 4 -1 -1 .
S ingleingle-acting acting cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
F i g u r e 4 -2 -2 . Do Double-ac uble-actin tin g cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 F i g u r e 4 -3 -3 . Nondiffere Nondifferential ntial cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 F i g u r e 4 -4 -4 .
Telescoping, ram-type, actuating cylinder . . . . . . . . . . . . . . . . . . . . . . 4-3
F i g u r e 4 -5 -5 .
Single-acting, spring-loaded, piston-type cylinder . . . . . . . . . . . . . . . . 4-3
FM 5-499 Page F i g u r e 4 - 6. 6. Do Double-ac uble-actin tin g, pist on-type cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4 F i g u r e 4 - 7. 7.
Cushioned, actuatin g cylind cylind er . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
F i g u r e 4 - 8. 8. Applications of cylin cylin ders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6 F i g u r e 4 - 9. 9. Basic operations of a hydraulic motor . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7 F i g u r e 4 -1 -1 0 . GearGear-type type m oto otor r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 F i g u r e 4 -1 -1 1 . Va ne-type m oto otor r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8 F i g u r e 4 -1 -1 2 . Pressure different different ial on a van ee-type type m oto otor r . . . . . . . . . . . . . . . . . . . . . . 4-9 F i g u r e 4 -1 -1 3 . Flo Flow w condition in a vanevane-type type pum p . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9 F i g u r e 4 -1 -1 4 . Roc Rocker ker arms pu shing vanes in in a pum p . . . . . . . . . . . . . . . . . . . . . . . . 4-10 F i g u r e 4 -1 -1 5 . In-line-axis, piston-type m oto otor r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10 F i g u r e 4 -1 -1 6 . S wash plate plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11 F i g u r e 4 -1 -1 7 . Bent-axis, piston-type m oto otor r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11
F i g u r e 5 - 1. 1.
Valves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
F i g u r e 5 - 2. 2.
S im ple relie relieff valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
F i g u r e 5 - 3. 3.
Com Co m pound rel relie ieff valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
F i g u r e 5 - 4. 4.
Pressure-reducing valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
F i g u r e 5 - 5. 5. X-se X-series, ries, pressure-redu pressure-redu cing va lve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4 F i g u r e 5 - 6. 6. Internal construction of an XC-series valve . . . . . . . . . . . . . . . . . . . . . 5-5 F i g u r e 5 - 7. 7.
S eq equence uence valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
F i g u r e 5 - 8. 8. Application of sequence valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6 F i g u r e 5 - 9. 9.
Coun Co un terba terbalance lance valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
F i g u r e 5 -1 -1 0 . Pressure switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8 F i g u r e 5 -1 -1 1 . S poo pooll valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9 F i g u r e 5 -1 -1 2 . Operation of a simple poppet valve . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10 F i g u r e 5 -1 -1 3 . Operation of slid ing-spoo ing-spool, l, d irec irectiona tiona ll-co con n trol valve . . . . . . . . . . . . . 5-10 F i g u r e 5 -1 -1 4 . S win gg-type type chec checkk valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 F i g u r e 5 -1 -1 5 . Vertical check check valv e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 F i g u r e 5 -1 -1 6 . S pring-l pring-loaded oaded check check valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11 F i g u r e 5 -1 -1 7 . S tandard chec heckk valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12 F i g u r e 5 -1 -1 8 . Restriction check check val ve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
FM 5-499 Page F i g u r e 5 -1 -1 9 . PilotPilot-ope operated rated chec checkk valv e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-13 F i g u r e 5 -2 -2 0 . PilotPilot-ope operated rated chec checkk valve, second second type . . . . . . . . . . . . . . . . . . . . . . . . 5-13 F i g u r e 5 -2 -2 1 . Two-way valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14 F i g u r e 5 -2 -2 2 . Flow conditions in a circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-15 F i g u r e 5 -2 -2 3 . Worki ng view of poppet-typ poppet-typ e, fo fou u r-way va lve . . . . . . . . . . . . . . . . . . . 5-16 F i g u r e 5 -2 -2 4 . S chem atic of a four four -wa y, directiona directiona l-c l-control, ontrol, slidin gg-spoo spooll valve . . . 5-17 F i g u r e 5 -2 -2 5 . Closed-center spool valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 F i g u r e 5 -2 -2 6 . Open-c Open-center enter sp oo ooll valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18 F i g u r e 5 -2 -2 7 . S hiftin g spoo spool by han d le lever ver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-20 F i g u r e 5 -2 -2 8 . S poo pooll shifted by pilo pilott pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21 F i g u r e 5 -2 -2 9 . S ole olenoid-ope noid-operated, rated, s lid ing-spoo ing-spool, l, d irec irectional tional -co cont nt rol valve . . . . . . . . 5-21 F i g u r e 5 -3 -3 0 . Cross section section of a gat e valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 F i g u r e 5 -3 -3 1 . Operation of a globe val ve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 F i g u r e 5 -3 -3 2 . Sectional view of a needle valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22 F i g u r e 5 -3 -3 3 . Fixed restrictor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 F i g u r e 5 -3 -3 4 . Varia ble restrictor restrictor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 F i g u r e 5 -3 -3 5 . Orifice ch ch ec eckk valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-23 F i g u r e 5 -3 -3 6 . Flow equalizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24 F i g u r e 5 -3 -3 7 . Typical meter-in circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25 F i g u r e 5 -3 -3 8 . Typical meter-out circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26 F i g u r e 5 -3 -3 9 . S pring tester tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28 F i g u r e 5 -4 -4 0 . Va lve inspection inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 F i g u r e 5 -4 -4 1 . Volum ee-co cont nt rol valv e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 F i g u r e 5 -4 -4 2 . PressurePressure-co cont nt rol v alve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29 F i g u r e 5 -4 -4 3 . Cartrid ge ge-type -type relief relief valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-30 F i g u r e 5 -4 -4 4 . Readin gs on a cartridge-type relie relieff valv e . . . . . . . . . . . . . . . . . . . . . . 5-30
F i g u r e 6 -1 -1 .
Graphical-circuit diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
F i g u r e 6 -2 -2 .
US AS I graphical graphical symbols symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
F i g u r e 6 -3 -3 . Rese Reservoir rvoir sym bo bols ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4 F i g u r e 6 -4 -4 . Hydraulic line sym bo bols ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
FM 5-499 Page F i g u r e 6 - 5. 5.
Crossing Cro ssing lines A an d B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
F i g u r e 6 - 6. 6.
Pump symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
F i g u r e 6 - 7. 7. Moto Motorr sym bols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6 F i g u r e 6 - 8. 8.
Cylinder sym bo bols ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
F i g u r e 6 - 9. 9.
Pressure-co Pressurecont nt rolrol-valv valv e sym bols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
F i g u r e 6 -1 -1 0 . Relie Relief-valve f-valve sym bol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 F i g u r e 6 -1 -1 1 . S equence equence--valv e sym bol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7 F i g u r e 6 -1 -1 2 . Check-valve symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8 F i g u r e 6 -1 -1 3 . Counterbalance-valve symbol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8 F i g u r e 6 -1 -1 4 . PressurePressure-redu redu cingcing-valv valv e sym bol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9 F i g u r e 6 -1 -1 5 . Flow-c Flow-controlontrol-valve valve sym bol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9 F i g u r e 6 -1 -1 6 . Un lo loadin adin gg-valve valve sym bo boll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9 F i g u r e 6 -1 -1 7 . Four-way, d irec irectional-co tional-cont nt rol rol-valve -valve sym bol . . . . . . . . . . . . . . . . . . . . 6-10 F i g u r e 6 -1 -1 8 . Mobile directional directional -c -controlontrol-val val ve s ym bol . . . . . . . . . . . . . . . . . . . . . . . 6-10 F i g u r e 6 -1 -1 9 . Fluid-c Fluid-co ond itione itionerr sym bo bols ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 F i g u r e 6 -2 -2 0 . Ac Acccum ulator sym bo boll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 F i g u r e 6 -2 -2 1 . Hydraulic Hydraulic-lift lift circuit circuit in neutral . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11 F i g u r e 6 -2 -2 2 . Manual-steering-gear layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 F i g u r e 6 -2 -2 3 . PowerPower-stee steerin rin g la yout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12 F i g u r e 6 -2 -2 4 . S em i-integral power-stee power-steering ring system . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13 F i g u r e 6 -2 -2 5 . Hydraulic circuit circuit diagram fo forr a ro road-patrol ad-patrol truck . . . . . . . . . . . . . . . 6-14 F i g u r e 6 -2 -2 6 . Hyd rau lic tester tester connecte connected d to a pu m p’ p’ss outpu t . . . . . . . . . . . . . . . . . . 6-15
F i g u r e 7 - 1. 1.
Comm on elec electrical trical schem atic sym bols . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
F i g u r e 7 - 2. 2.
Com Co m parison of elec electric trical al and hyd rau lic co com po ponents nents . . . . . . . . . . . . . . 7-3
F i g u r e 7 - 3. 3.
Comparison of electrical and hydraulic circuits . . . . . . . . . . . . . . . . . . 7-4
F i g u r e 7 - 4. 4.
S chem atic diagram s illustrating z ero refe refere rence nce point point . . . . . . . . . . . . . 7-9
F i g u r e 7 - 5. 5. Battery installed installed be betwee tween n earth groun d an d chassis groun groun d . . . . . . . 7-11
FM 5-499
Tables Page Table 22-1. 1.
Figu re colors colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Table 55-1. 1.
Classifications of directional-control directional-control va lves . . . . . . . . . . . . . . . . . . . . 5-16
Table 66-1. 1.
Proble Pro blem m s and solutions with pum p operatio operations ns . . . . . . . . . . . . . . . . . 6-17
Table 66-2. 2.
Proble Pro blem m s and solutions with actuat ing m echanism . . . . . . . . . . . . . 6-19
Table 66-3. 3.
Proble Pro blem m s and solutio solutions ns w ith h eating oil oil . . . . . . . . . . . . . . . . . . . . . . 6-20
Table 66-4. 4.
Proble Pro blem m s and solutions with fluid m otors . . . . . . . . . . . . . . . . . . . . . 6-21
Table 66-5. 5.
Proble Pro blem m s an d so solutions lutions w ith ac accum cum ulator operatio operation n . . . . . . . . . . . . . 6-21
Table A-1.
Metric conversion chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Appen dix-1
FM 5-499
Preface
This fiel field d man ua l (FM) (FM) serves as a gu ide for for personn personn el who operat operat e and m aint ain m ilitar ilitar y equipment using hydra uliculic-powered powered cont cont rol systems. It includes includes general in format ion ion coverovering basic hydrau lics lics an d describes describes t he pr opert ies and cha ra cterist ics ics of fluids an d several types of pum ps, motors, motors, valves, and cont cont rols. This m an ua l also deals with piping, tu bing, an d hoses used t o co convey fluid fluid un der pr essur e. It describes describes th e fun fun ctions an d types of reservoirs, voirs, stra iners, fil filter ter s, and a ccum ulat ors. It discusses discusses t he pu rposes and t ypes of of seals an d packings used in fluid power power syst ems. The content content s of th is man ua l are applicable applicable to both both nu clear an d nonnu clear warfare. The Appendix Appendix contains contains a n E nglish to metric measu remen t conversion conversion cha cha rt .
ACKNOWLEDGEMENTS Ackn Ackn owledgment wledgment is grat efully efully made t o the organizations listed below below for for permitt ing th e use of copyright opyright ed mater ial in in prepar ing this ma nu al. Deere & Compa Compa ny Moline, Illinois Comp an y. c 1997. Deere & Compa Compa ny. All Hydraulics . "Reproduced by perm ission of Deere & Comp rights r eserved." eserved." Vickers, Vickers, I nc. Rochest Rochest er H ills, Michiga Michiga n dition 1993. Industrial Hydraulics Manual, Third E dition
The proponen proponen t for for th is publicatio publication n is Headqu ar ters (HQ), (HQ), United Stat es Arm Arm y Training and Doc Doctr ine Comm Comm an d (TRAD (TRADOC) OC).. Subm it chan ges fo for impr oving this publicat publicat ion ion on Depa rt ment of the Army (DA) (DA) Form Form 2028 (Rec (Recommended ommended Ch an ges to Pu blic blicat ions ions an d Blank Forms) an d forwar forwar d it t o Co Comm an dan t, USAES, ATTN: ATTN: ATSE-TDATSE-TD-DD-P, P, Fort Leona Leona rd Wood, Wood, MO 65473-6650. 65473-6650.
Unless other wise stat ed, masculine masculine n ouns a nd pr onoun onoun s do not not r efer efer exclusivel exclusively y to men.
FM 5-499
CHAP CHA P TER 1
Hydraulic Basics Hyd raulics is the scie science nce of transm itting forc force and/ or m otio tion n through t he mediu m of a confined liqu id. In a hyd raulic devic devicee, power power is transm itted by pushin g on on a confin ed liqu id. Figure 1-1 1-1 shows a sim ple hyd raul ic d evice vice.. Th e transfer of of en en ergy tak es place bec because ause a quan tity of liquid is subject subject to pressure. pressure. T o ope operate rate liquid -po -powered wered systems, th e operator operator should h ave a kn owle owled d ge of th e basic natu re of liqu ids. T his cha pter cove covers rs the properties properties of of liquids an d h ow th ey act und er differe different nt co cond nd itio itions. ns. 1 -1 -1 . P r e s s u r e a n d F o r c e . Pr essur e is force force exert exert ed again st a spec specif ific ic ar ea (fo (force per u nit area ) expressed in in poun ds per squa re inch inch (psi). (psi). Pressu re can can cau se an expan sio sion, n, or or resista nce to co comp mp res sion, of of a fluid th at is being squeezed. A fl fluid uid is an y liqu liqu id or or gas (vapor). Force is an ythin g th at ten ds to produce or m odif dify y (push (push or pull) motio motion n a nd is expressed in pounds.
a . Pressure. An exam exam ple of of pressu re is the air (gas) th at fills fills an a ut omo omobile bile tire. As a tire is inflat inflat ed, more air is squeezed squeezed into it it th an it can h old. The air inside a tire resists th e squeezing squeezi ng by pus pus hing out out war d on on th e casing casing of th e tire. The out out war d push of the air is pressur e. Equa l pressu re thr ough out a co confined area is a cha cha ra cterist ic of an y pressurized fluid. fluid. For exam exam ple, in an inflated tire, the out out war d push of the air is uniform uniform t hr ough out . If it were not, a t ire would would be pu shed int o odd odd sh apes because of its elast ic icity. ity. There is a ma jo jorr diff differen eren ce between betwe en a gas an d a liquid. li quid. Liquids ar e slightly compressible (Figu (Figu re 1 -2, page 1-2). 1-2). When a confined co nfined liquid is pushed on, pressur pressur e builds up. The pressure is st ill transmitted equally throughout the co cont ainer. The fluid's beh avior ma kes it possible possible to transmit a push thr ough pipe pipes, s, around corner s, and up and do down. A hydra ulic system uses a liquid
Weight
Confined liquid is subject to pressure
F i g u r e 11 -1 . B a s i c h y d r a u li li c d e v i c e
FM 5-499 becau se its becau its n ear incompr incompr essibi essibility lity makes th e action action insta nt an eo eous us a s long long as t he system is full of liqu id. Pr essur e can can be creat creat ed by squeezing squeezing or push ing on a confined confined fluid fluid only if there is a resista nce to flo flow. w. The two ways to push on a fluid ar e by the action action of a m ec echa ha nical pum p or by th e weight weight of the fluid. fluid. An example of of pressu re du e to a fluid's fluid's weight weight wo would uld be in a n ocean oc ean 's depth depth s. The water 's weight weight crea crea tes th e pressur e, which increases increases or or decrea decrea ses, depending depe nding on th e depth. By knowing knowing t he weight of a cubic fo foot of of wat wat er, you you can calc alcula ula te th e pressu re a t a ny depth . Figure 1-3 shows shows a column column of wat er 1 fo foot squa re an d 10 feet feet high, which which equa tes t o 10 cub cub ic fee feet. t. (On e cu cu bic fo foot ot of of wat er weighs 52.4 pou pou nds .) The tot al weight of wa ter in th is column is 624 poun poun ds. The weight a t t he bottom covers covers 1,445 squar e inches inches (1 squar e foo foot). t). Ea ch squar e inch inch of th e bott bott om is su bje bjecct t o 1/144 1/144 of of th e total weight , or or 4.33 poun poun ds. Thu s, th e pressur e at t his depth is 4.33 psi. psi. You can a lso create an equ al pressu re of of 4.33 psi in in a liquid liq uid u sing th e pum p an d figures figures sh own in F igure 1-4, page 1-4. 1-4. Before pressure, head was th e only Bef only way to exp express ress pressur e measurement . It was expressed as feet feet of wat er. Today, head is still the vert ic ical al distan ce between t wo leve levels ls in a fluid. In F igure 1-3, 1-3, the head bet ween th e top and bottom of of th e wat er is 10 fee feet, t, which which is equiva lent t o 4.33 psi. Ther efo efore, re, each foo foot of wat er is equa l to 0.433 psi. The earth has a n at mosphere of of air extending 50 mile miless up, and th is air has weight. weight. This air crea tes a h ead of pressu re th at is called called atm osph eric pressu re. A col olum um n of air 1 squar e inch inch in cross section section an d th e height of th e atm ospher e would would weigh weigh 14.7 poun poun ds at sea level. level. Thu s, th e earth 's atm ospher ic pressu re is 14.7 14.7 psi at sea level. level. The role of at mospher ic pressu re in in
A gas is compressible
A liquid resists compression
F i g u re r e 1 -2 -2 . C o m p re r e s s i b i li li t y
FM 5-499 most hydra ulic systems is signifi significant. cant. Figur e 1-5, 1-5, page 1-4, 1-4, shows th e int eractio eraction n of hydraulic and at mosp mospheric heric pressur pressur es under the three sets of conditions listed below: (1) Diagra m A. A. In the diagram diagram , th e tu be is open open at bo both th ends. When it is placed placed in a liquid, li quid, th e liquid will will rise, inside and out side, in in propo proport rt io ion n to th e am oun t of liquid liquid displaced displace d by the su bmerged tu be wall. (2) Diagram B. In the diagram, ends of of th e tube ar e clo closed. sed. When placed in in a liquid, th e liquid level in t he t u be is fo for ced down becau bec au se the air in t he tu be must occ ccupy upy a spa ce. Ther ef efore, ore, th e liquid is displa ce ced. d. The liquid liquid level out side the t ube rises in p roport po rt io ion n to th e volume volume of the cylinder cylinder wall an d th e volume volume of th e tra pped air below below th e original liquid liquid level. level. The at mospheric pressur e (14.7 (14.7 psi) on t he liquid out out side the t ube is not h eavy enough t o fo force th e liquid inside the tu be upward against th e pressur pressur e of of th e tr apped air , which is more tha n 14.7 psi. (3) Diag Diagram ram C. In the diagram, diagram, the upper end of the t ube is closed, closed, but so some me of the a ir ha s been removed removed from from this tu be so tha t th e pressure pressure within th e tube is is less less than 14.7 psi (a (a pa rt ial vacuum ). A perfect vacuu m would would exist if if all pressur e with with in the tu be co could be eliminat ed, a co condit io ion n th at never ha ppens . Bec Becau au se th e liq liquid uid out out side th e tu be is subject subject t o full full at mospheric pressur e, th e liquid liquid is forced forced up int o th e tu be to sat isf isfy y the vacuu vacuu m. How far far the liquid liquid rises depends on the difference difference in in air p ressur e between betwe en th e trapped air and th e atmosphere.
1 ft 1 ft
0.433 psi
1 cu ft weighs 62.4 lb
10 ft
2.165 psi
Total weight 624 lb 4.33 psi
b . Force. The r elat io ionsh nsh ip of fo force, rce, pressur e, an d ar ea is as follo follows: ws: F = PA
1 ft
144 sq in
where — F = force force,, in p oun d s P = pressure, in p si A = area, in squ are inches
F i g u r e 1 -3 -3 . Wa t e r c o lu lu m n
FM 5-499 Example:
Figur e 1-6 1-6 shows a pressu re of 50 psi being applied to an a rea of 100 square inches. The total force force on on th e ar ea is—
Area = 10 sq in
F = PA F = 50 x 100 = 5,000 poun ds
Weight
1-2. P asc al' 1-2. al'ss Law. Blaise Pascal fo form ulat ed th e basic law of of hydra ulics in in the m id 17th centu ry. He disco discovered th at pr essur e exe exert rt ed on a fluid acts equally in all directio directions ns . His law stat es tha t pr essure in a confi nfined ned fluid fluid is tra nsmitt ed undiminish ed in in every directio direction n an d acts with equal force force on on equa l areas an d at right an gle gless to a cont cont ainer 's walls.
Figur e 1-7 Figur 1-7 shows shows the appara tus t hat Pascal us ed to develo develop p his law . It con con sisted of two conconnected cyli cylind nd ers of diff different erent diamet ers with a liquid li quid trapped betwee between n th em. Pascal fo foun d tha t th e weight weight of a sm all piston will will balance the weight weig ht of a lar ger piston a s long as th e piston’s piston’s areas ar e in in proportio proportion n t o the weig weight s. In th e sma ll cyli cylinder nder , a force force of of 100 pounds on a 11-squa squa r einch piston creat es a pressu re of 100 psi. Ac Acco cord rd ing to Pascal's Pascal's Law, th is pressure is tra nsmitted un diminished in eve every ry direction. direction. In th e larger
A
Pump Force = 43.3 lb
Area = 10 sq in Pressure = 4.33 psi
F ig i g u r e 1 -4 -4 . P u m p p re r e s s u re re
B Atmospheric pressure
Pressure = 4.33 psi
C Atmospheric pressure
F i g u r e 1 -5 -5 . I n t e r a c t io io n o f h y d r a u l i c a n d a t m o s p h e r i c p r e s s u r e s
FM 5-499
cyli ylinder, nder, th e 100 psi of pressu re from th e sma ll cyli cylinder nder is tr an smit ted to an ar ea of of 5 squa re inches, which resu lts in a force force of of 500 poun po un ds on on t he seco second piston. The force force ha s been mu ltiplie ltiplied d 5 times—a mecha mecha nic nical al adva nta ge of of 5 to 1. Using th e sam e facto factors, rs, you you can determ ine th e dista nce th e pistons move. move. For example, if th e sma ll piston piston move movess down 10 inches, the lar ger piston will move move up 2 inches. Use th e fol follo lowing wing to determ ine the distance:
s n d u o 0 p 0 , e 5 0 c o r c f o 10”
F 1 × D 1 D 2 = ------------------F 2
10” 100 sq in
where — F 1 = fo forc rcee of the sm sm all pisto piston, n, in pounds D 1 = distance distance the small piston piston m ove ves, s, in in inches D 2 = distan ce the the larger larger piston piston m oves, in inches F 2 = fo forc rcee of the larger larger pisto piston, n, in pound s
i p s 5 0
F i g u r e 1 -6 -6 . F o r c e , p r e s s u r e , a n d a r e a
E x a m p l e : Determine D 2
F 1 × D 1 D 2 = ------------------F 2
100 × 10 D 2 = --------------------500
D 2 = 2 in
500 lb
100 lb W
P
10”
2”
100psi
1 sq in 5 sq in
F i g u r e 11 -7 . P a s c a l ’s ’s La La w a p p a r a t u s
FM 5-499
1-3. Flow. Flow is is th e movemen movemen t of a hydr au lic fl fluid uid caus ed by a difference difference in th e pressur e at two points. points. In a hydr aulic system system , flo flow w is usua lly produced by th e action action of a h ydrau lic pum p— p—aa device device used to co cont inuously push on a hydra ulic fluid. The two ways of of measur ing flow fl ow are velocity velocity a n d flow flow ra te.
a . Velocity. Ve Velo loccity is t he a verage speed at whic which h a fluid's par tic ticles les move move past a given point poi nt , measu red in feet per second second (f (fps). ps). Velo eloccity is an importan t considera considera tion in sizing th e hydra ulic li lines nes t ha t carr y a fluid fluid between between t he compo componen nen ts. b. Flo Flow w ra te is th e measu re of how much volume volume of a liquid liquid pass es a point point in Flow w Rat e. Flo a given given time, measu red in gallons gallons per min ut e (GPM). Flow ra te determines th e speed speed at which whic h a load m oves an d, th eref erefo ore, is importan t wh en considering considering p ower. work an d is expressed in footfoot1-4. En ergy, Work, and P ow er. En ergy is th e ability to do wo 1-4. pound (ft (ft lb). lb). The th ree fo form s of of energy are poten poten tial, kinet kinet ic ic,, and hea t. Wo Work rk m easu res accompli acc omplishm shm ent s; it it r equires motion to mak e a force force do wo work rk . Power is the r at e of of doi doing ng work wo rk or th e rat e of of energy tra nsfer. a . Potential Energy. Potent ial ener ener gy is is energy due to posi position. tion. An objec objectt ha s potential energy in proport proport io ion n t o its vertical vertical dista nce above above the ear th 's surface. For example, wat wat er held back by by a dam r epresent s potent potent ial energy bec becau se unt il it is released, the wat er does does not work. In h ydrau lic lics, s, poten poten tial ener gy is is a st at ic factor. When force force is is applied to a co confined liquid, as sh own in Figure 11-4 4 (page 1-4) 1-4),, poten poten tial ener gy is present bec becau au se of the sta tic pressur e of of the liquid. liquid. Potent ial energy of of a m ov oving ing liquid liquid can be redu ced by the h eat energy released. Potent ial energy can can also be redu ced in in a m oving liquid liquid when it tr an sfo sform rm s into kinetic energy. A movi moving ng liquid can can , therefore, therefore, perform perform wo work rk a s a r esult of its st at ic p r e ss ss u r e a n d i t s m o m en en t u m . b. Kinetic En erg possesses becau becau se of its its m otion. ergy. y. Kinetic energy is th e ener gy a body possesses The greater th e speed, speed, the greater th e kinetic energy energy.. When water is released from from a da m, it ru shes out a t a high veloc velocity jet, repr esentin g energy of of motio motion—kinetic n—kinetic energy. The am oun t of kinetic energy in a mov moving ing liquid is directly proport proport io iona na l to th e squa re of its its vel velo ocity. Pressu re caused by kinetic energy may be called called velo veloccity pressu re. c. Heat Energy and Friction. Heat energy is th e energy a bo body dy possesses possesses becau becau se of its heat . Kinetic energy and heat energy are dynamic factors. Pa sc scal's al's Law dealt with with st at ic pressur e an d did not include the friction friction factor. factor. Fr ic iction tion is th e resista nce to relative motion motion between t wo bodies. When liquid flows flows in a hydr au lic circ circuit uit , fric friction tion produ ces heat . This cau ses some of the kinetic energy t o be lo lost in th e form form of hea t en ergy. Although friction friction cann ot be eliminat ed entir ely ely,, it can can be co cont roll rolled ed to some extent. The th ree m ain cau ses of exc excessive essive frictio friction n in h ydra ulic system system s ar e— •
E xt x t r em e m el e l y lo lon g li li ne n e s. s.
•
N u m e r ou ou s b en en d s a n d fi fi t t in in g s or or i m p r op op e r be be n d s .
•
Excessi Exc essive ve vel velo ocity from from using undersized undersized lines. lines.
In a liq liquid uid flowing flowing thr ough s tr aight pipin g at a lo low w speed, the par ticl ticles es of of the liquid liquid move in str aight lines pa ra llel to the flow flow direction. direction. Hea t loss loss from from friction friction is minimal. This kind of flo flow w is called lam ina r flow. flow. Figu re 1-8, dia gra m A, sh ows lam lam ina r flow. flow. If the speed
FM 5-499
increases beyond a given point, turbulent flow develops. Figure 1-8, 1-8, diagra m B, shows tur bulent flow. flow.
A
Figure 1-9 shows th e difference in head because of pres su re dr op due t o fric fric-tion. Point B shows no fl flow ow resistance (free-flow condition);; th e pressur e at point tion) B is zero zero.. The pressur e at point po int C is at its maximum becau bec au se of of th e head a t point A. As the liquid flows flows from point C to point point B, frictio riction n causes a pr essur e drop from from maximum pressur e to zero pressu re. This is r ef eflec lected ted in a s ucc ucceedeedingly dec decreas reas ed head a t points po ints D, E, and F. d . Relationship Betw Be tw ee een n Velo Velocity city an d Pres1-10, page 1-8, sure. Figur e 1-10, explains Bern ouilli' uilli'ss Pr incipl iple, e, whic which h stat es th at the
Laminar flow
B
Turbulent flow
F i g u r e 1 -8 -8 . L a m in i n a r a n d t u r bu b u l e n t f lo lo w
D
E
F
A
C
B
F i g u r e 1 -9 -9 . E ff f f e c t o f fr fr i c t io io n o n p r e s s u r e
