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Section VII – Service, Inspection & Maintenance 

A. Service Tools 

No special tools are required to service this valve series.

B. Inspection 

Periodic inspection of the fluid condition and tube or piping
connections can save time consuming breakdowns and
unnecessary parts replacement. The following should be
checked regularly.

1. All hydraulic connections must be kept tight. A loose

connection in a pressure line will permit the fluid to leak out.
If the fluid level becomes so low as to uncover the inlet pipe
opening in the reservoir, extensive damage to the system
can result. Loose connections also permit air to be drawn
into the system resulting in noisy and/or erratic operation.

2. Clean fluid is the best insurance for long service life.

Therefore, check the reservoir periodically for long service
life. Therefore, check the reservoir periodically for dirt and
other contaminants. If the fluid becomes contaminated, flush
the entire system and add new fluid.

3. Filter elements should also be checked periodically

for dirt and other contaminants. If the fluid becomes contami-
nated, flush the entire system and add new fluid.

4. Air bubbles in the reservoir can ruin the valve and

other components. If bubbles are seen, locate the source of
air and seal the leak.

C. Adding Fluid to the System 

When hydraulic fluid is added to replenish the system, pour it
though a fine wire screen (200 mesh or finer). When
applicable, pump the fluid through a 10 micron filter. DO NOT
use a cloth to strain the fluid or lint may enter the system.

D. Adjustments 

No periodic adjustments are required other than normal
system maintenance.

E. Replacement Parts 

Reliable operation throughout the specified operating range
is assured only if genuine Vickers parts are used. Sophisti-
cated design processes and material are used in the
manufacture of our parts. Substitutions may result in early
failure. Part numbers are shown in the parts and service
drawings listed in Table 1.

F. Product Life 

The service life of this product is dependent upon environ-
ment, duty cycle, operating parameters and system
cleanliness. Since these parameters vary from application to
application, the ultimate user must determine and establish
the periodic maintenance required to maximize life and
detect potential component failure.

G. Troubleshooting 

Table 5 lists the common difficulties experienced with
directional valves and systems. It also indicates the probable
causes and remedies for each of the troubles listed.

Always remember that many apparent failures may actually
be the failure of other parts of the system. The cause of
improper operation is best diagnosed with adequate testing
equipment and a thorough understanding of the complete
hydraulic system.

Trouble

Possible Cause

Remedy

Valve spool fails to move

Dirt in system

Solenoids inoperative

Improper assembly

Improper installation connections

Disassemble, clean and flush

Check electrical source and solenoids

Check proper assembly. Refer to ap-
propriate figure and assembly procedure

Check installation drawings

Valve produces undesirable response

Improper valve assembly
Improper installation connections

Solenoid wiring reversed

Check parts drawing and installation
drawing for proper assembly and instal-
lation connections

Reverse connections to the solenoids

Table 5. Trouble Shooting Chart

Summary of Contents for DG17/20V-3 Series

Page 1: ...I 3618 S Revised 11 1 86 Directional Controls Overhaul Manual Vickers Directional Controls...

Page 2: ...2...

Page 3: ...nternal Valve Functions 23 A General 23 B Pilot Pressure 23 C Pilot Valve Drains 23 D Internal Check Valves 23 VI Installation 24 A Installation Drawings 24 B Fluids and Seals 24 C Piping and Tubing 2...

Page 4: ...2 shows a complete breakdown of the model codes covering these units Service inquiries should always include the complete model code number as stamped on the nameplate Table 1 Related Publications Mo...

Page 5: ...Design I 3546 S I 3546 S I 3546 S I 3567 S I 3568 S I 3551 S I 3551 S I 3632 S Installation Drawing 514500 514500 514500 514705 514705 514381 514701 514701 DG17S DG17S8 DG17 20V 3 SERIES 53 Design I 3...

Page 6: ...S2 012A DC DG4S2 012A H DG4S2 012C AC DG4S2 012N AC DG4S2 012N DC DG4S2 012N H DG4S2 01 A W 3 DG4S2 01 N W 3 DG4S4 01 A AC DG4S4 01 A DC DG4S4 01 A H DG4S4 01 A W 3 DG4S4 01 B W 3 DG4S4 01 C AC DG4S4...

Page 7: ...0 D W 3 DG5S4 10 D AC DG5S4 10 D DC DG5S4 10 D H DG5S4 10 D DG5S4 10 N DG5S4 10 N M I 3439 S I 3440 S Installation Drawing DG5S H8 DG5S 8 DG5S4 H06 DG5S4 06 DG5S4 10 XDG5S4 06 XDG5S4 10 SERIES 20 21 D...

Page 8: ...C XDG5S4 10 D XDG5S4 10 N DG5S H8 DG5S 8 DG5S4 H06 DG5S4 06 DG5S4 10 XDG5S4 06 XDG5S4 10 SERIES Model Description 10 11 Design Installation Drawing 20 21 Design 40 Design 50 Design 51 Design 53 54 De...

Page 9: ...4 Four way omit for DG5S 8 DG5S H8 models 14 Pilot Pressure Range pressure centered D models only A 200 1000 psi B 1000 2000 psi omit 2000 3000 psi 15 Valve Type A Spring offset one solenoid B Spring...

Page 10: ...valves are pilot pressure operated A two stage valve is constructed by combining a pilot valve and a larger main stage valve into one assembly The pilot valve usually a DG4S4 01 DG4V 3 or DG18V 3 is...

Page 11: ...ion b Type 1 spool is designed with ports P A and T interconnected Port B is blocked in center position c Type 9 spool is similar to type 0 spool except all ports are partially open in center position...

Page 12: ...considerable force to move the spool when it is under pressure For this reason the two inch valve size is not available with a manual lever control Examples of valves with the manual lever control are...

Page 13: ...can be obtained a type B and a type C If one solenoid is used on a spring centered pilot valve the model code is identified with the letter B When two solenoids are used the model code is identified w...

Page 14: ...left end of the spool Since the spool land area at the right side is greater than the piston area the spool will be forced to the left until the piston shoulder butts against the sleeve center positi...

Page 15: ...pressure enters piston area causing the main stage spool to shift to the right Main stage flow from P B and A T is obtained A Sleeve Tank Detent Figure 8 Detented N Model Main Stage 1 Solenoid A is e...

Page 16: ...ilot choke details 3 Fast Response Option Some applications require the main stage spool to shift at a faster than normal rate For such applications the fast response option is used This option requir...

Page 17: ...ure 10a Pilot Choke DGFN 01 20 Use with DG4S4 01 Series DGMFN 3 21 5 6 7 8 11 3 2 1 10 4 9 Part No Part Name Qty 1 Retaining Ring 2 2 Plug 2 3 O Ring 2 4 Spring 2 5 Check Valve 2 6 Stop 2 7 O Ring 2 8...

Page 18: ...most cases a number 6 type pilot spool is used When a type 4 or 8 main stage spool is used the number 6 pilot spool is identified as number 68 This spool com bination requires the pilot valve to be as...

Page 19: ...itioning of the pilot valve spool within the body In some valves a roller is used instead of a lever to actuate the pilot spool 2 Remote Pilot Pilot valves such as a DG3V 3 40 are available for use wi...

Page 20: ...Air gap solenoids are isolated from system fluid and can be removed and replaced without disturbing the system A push pin and sliding seal arrangement couple the solenoid to the valve spool see Figur...

Page 21: ...ngements The monitor switch is a single pole double throw contact arrangement with A normally closed and B normally open Switch ratings are noted on installation drawing Table 1 The monitor switch hou...

Page 22: ...Pin Terminal Box Body End Cover A B or F Models Manual Override Plunger Wet Armature Solenoid Pilot Spool Solenoid Coil Core Tube C Models Solenoid A Missing Figure 13b DG4S4 W 50 Pilot Valve Sectiona...

Page 23: ...pilot pressure vs tank pressure Refer to the unit installation drawing for minimum pressure ratings Internal pilot drain models have the letter T stamped on the unit nameplate i e DG5S4 062 t 51 NOTE...

Page 24: ...1 S for pickling instructions 2 To minimize flow resistance and the possibility of external leakage use only the necessary fittings and con nections required for proper installation 3 The number of be...

Page 25: ...s are required other than normal system maintenance E Replacement Parts Reliable operation throughout the specified operating range is assured only if genuine Vickers parts are used Sophisti cated des...

Page 26: ...slotted screws and unplug the electrical wiring from the pilot section b If the valve has an air operated pilot section turn off air supply and disconnect the pressure lines from the connection plate...

Page 27: ...2 Screw 4 13 Cover 1 14 O Ring 1 15 Spring 1 16 Washer 1 17 Spool 1 18 O Ring 3 19 O Ring 2 20 O Ring 1 21 Seat 1 22 Poppet 1 23 Spring 1 24 Sleeve 1 25 Rest Pin 2 26 48 Plug 13 Consecutive even s 27...

Page 28: ...ates a check valve problem If check valve removal is necessary perform step 7 7 Select the correct screw listed in Table 6 Obtain a piece of pipe or tubing with an inside diameter that is slightly lar...

Page 29: ...1 11 Spring 1 12 Sleeve 1 13 Piston 1 14 Spool 1 15 Screw 4 16 Cover 1 17 O Ring 1 18 Spring 1 19 Washer 1 20 45 Plugs O Rings 13 each 46 O Ring 4 47 O Ring 1 48 O Ring 1 49 O Ring 1 50 Rest Pin 2 25...

Page 30: ...8 39 DG4S4 01 W3 51 15 a 19a 18a 17a 15a Detent S A 1 N 16 Washer 1 B C 17 Screw 4 C N 17a Screw 4 A B 18 Coil S A 1 C N 18a Cover 1 A B 19 Gasket 1 C N 19a O Ring 1 A B 20 Screw 2 C N 21 O Ring 1 C N...

Page 31: ...Snap Ring 1 9 Guide 1 10 O Rings Guide 1 11 Limiter 2 12 Spring 1 13 Snap Ring 1 14 Guide 1 15 O Ring 1 16 O Ring 1 17 Washer Seal Retainer 1 18 Spring 1 19 Spacer 1 20 Washer Spring Centering 1 21 S...

Page 32: ...F N 13 O Ring 1 A B C F N 14 Core Tube S A 1 A B C F N 15 O Ring 1 A B C F N 16 Push Pin 1 A B C F N 17 Spring 1 A B C N 18 Washer 1 C F Item Nomenclature Quantity Model Source Code 19 Detent S A 1 N...

Page 33: ...DG18V 3 C 40 11 1 2 3 4 5 6 7 8 9 10 12 13 14 15 16 17 1 Screw 4 2 End Cover 2 3 Manual Plunger 2 4 O Ring 2 5 Plunger 2 6 Seal 2 7 Guide 2 8 O Ring 2 9 Pin 2 10 O Ring 2 11 Retainer 2 12 Spring 2 13...

Page 34: ...faces washers and manual plungers for burrs cracks or mushrooming Replace all parts that show evidence of wear 5 Visually inspect the internal coring bore of each body for heavy scratches or erosion a...

Page 35: ...g 15 on end of spool 17 NOTE Spring 15 and washer 16 do not exist on spring offset A or floating type models h Install O Ring 14 into cover 13 as shown i Fasten cover 13 to end of body 6 with four scr...

Page 36: ...model code If left hand LH assembly is required reverse all pilot parts except body and spool 1 Install O Rings 35 and 37 on plugs 34 and 36 Lubricate plug threads and install into body 38 as shown To...

Page 37: ...40 DG5S4 04 X K R S 40 DG5S4 04 X E K R S 40 DG5S4 04 T 40 DG5S4 06 51 DG5S4 06 X 51 DG5S4 06 E 51 DG5S4 06 X E 51 DG5S4 06 K R 51 DG5S4 06 E K R 51 DG5S4 06 X K R 51 DG5S4 06 X E K R 51 DG5S4 06 T 5...

Page 38: ...pecial fixtures is required to fully test the performance of the rebuilt unit Because of this only the functional test shown in the start up paragraph is given If such a test stand is available test t...

Page 39: ...E K R S 40 DG5S4 04 X E K R S 40 In In In In Out Out In Out Denotes Orifice Plug B P T A P Port B Plug C Plug X Port In Out In In NOTE Open Center Spools 0 4 8 9 cannot function unless External Pilot...

Page 40: ...6 X E 51 In In Out In Out In Out Denotes Orifice Plug B P T A B Plug C Plug X Port Out T Figure 24b DG5S4 06 K R 51 Internal Pressure Passages Plug Locations Plug Installation Table Model C Plug B Plu...

Page 41: ...s Y Port T Drain Port Internal Coring Figure 25a DG5S4 H06 51 Internal Pressure Passages Plug Locations Plug Installation Table Model C Plug B Plug A Plug DG5S4 H06 C 51 DG5S4 H06 C E 51 DG5S4 H06 C X...

Page 42: ...5S4 H06 C E KRS 51 DG5S4 H06 C X KRS 51 DG5S4 H06 C X E KRS 51 In In Out In Out In Denotes Orifice Plug B P T A T A Plug Check Valve Pressure Pickup Line In Out B Plug C Plug Gauge Connection Figure 2...

Page 43: ...n Out In Denotes Orifice Plug B P T A T C Plug Does not Exist Out B Plug X Port Figure 26b DG5S4 10 K R S 53 Internal Pressure Passages Plug Locations Plug Installation Table Model C Plug B Plug A Plu...

Page 44: ...Models T Drain Port Internal Coring Y Port Figure 27a DG5S 8 10 or DG5S H8 20 Internal Pressure Passages Plug Locations B P A T P Port Plug Installation Table Model C Plug B Plug A Plug DG5S 8 10 DG5S...

Page 45: ...G5S 8 E KRS 10 DG5S 8 X KRS 10 DG5S 8 X E KRS 10 In In Out In Out In Denotes Orifice Plug Does not Exist Out C Plug Check Valve A Plug Figure 27c DG5S8 10 or DG5S H8 20 Internal Drain Passages Plug Lo...

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