Danfoss KVF Installation guide

DESCRIPTION

The KVF Flow Control Servovalve is a precision servovalve
that provides an output flow rate proportional to a low power
electrical input signal. It features a torque motor-actuated,
double-nozzle flapper pressure control pilot valve mated to a
pressure-actuated, spring-centered boost valve module of a
unique double-spool configuration.

The design of this servovalve does not require a centering
feedback spring and ball for spool position. The servovalve's
pilot stage is a stand-alone, closed loop pressure control
valve which uses internal hydraulic pressure reactions to
achieve its closed loop control characteristics.

This combination was selected to provide fabrication
economies resulting in true servovalve performance at
proportional valve pricing. The KVF Servovalve's steady
state/dynamic response characteristics are compatible with
industrial feedback control system applications.

FEATURES

KVF

Flow Control Servovalve (FCS)

BLN-95-9061-4 Issued: February 2004

Self-contained pressure feedback, eliminates requirement
for feedback spring and ball for spool position

ISO 4406 filtration rating of 18/15 (Nominal 10 micron
filtering provides dependable performance)

Standard manual operator assists with operation and
system diagnostics

Requires low power dc current to drive rated flow;
±20 mA, ±40 mA, ±100 mA, ±150 mA, or ±220 mA, are
standard options. The ±20 mA, can be driven directly
from PLC.

Does not require PWM drive for dither but is directly
compatible with other drives

4 to 20 mA version is configured such that 4 mA = 0 flow
and 20 mA = maximum flow

Unique two spool main body design allows for factory
adjustment of null pressures at each working port

Units available in standard line-to-line or overlapped
configuration in all flows from 1 1/4 gpm to 20 gpm at no
additional cost

Installation dimensions common to all servovalves

Pricing is independent of flow capability

Four connector option: MS, 2-pin WP, 4-pin WP, or 2-2
pin WP

Easily connected for unidirectional use from 2 1/2 gpm to
35 gpm at 1000 psi rating

Adaption maniflods available for conversion to other
valve patterns

Dual spool design provides added safety shut down if
contamination causes failure of either spool

Capability of separating control source from main stage
supply to accommodate high back pressure applications

ORDERING INFORMATION

KVF X X X X X

Device Identity

Rev

Supply Pressure

Flow Rating

% Lap Split

Pilot Stage

© Danfoss, 2013-09 BLN-95-9076-2 1

Ordering specifications for standard models.

DEVICE IDENTITY

The modle code for this device is KVF.

MODEL CODE SUPPLY PRESSURE

A 500 to 3000 psi
C 200 to 1000 psi
D 500 to 3000 psi with separate pilot drain
E 2500 to 3000 psi
F 500 to 3000 psi w/o cylinder port orifices
G 500 to 3000 psi w/o cylinder port orifices

and with pilot drain

ORDERING INFORMATION (continued)

FLOW RATING
MODEL CODE FLOW RATING

1 1.25 gpm
2 2.5 gpm
5 5 gpm
6 10 gpm
7 15 gpm
8 20 gpm

9 20 gpm with 300 lb/in springs

PILOT STAGE

PILOT STAGE DEVICE NUMBER RATED CURRENT COIL(s) CONNECTOR TYPE SCALE FACTOR

01 * MCV116A3102  ±150 mA 23 ohms Packard 1.15 psid/mA
02 * MCV116A3101  ±150 mA 23 ohms MS 1.15 psid/mA
03 * MCV116A3204  ±220 mA 16/19 ohms Packard 0.78 psid/mA
05 * MCV116A1307  ±40 mA 69 ohms MS 4.2 psid/mA
06 MCV116A1407  ±40 mA 106 ohms MS 5.5 psid/mA
07 MCV116A1402  ±40 mA 106 ohms Packard 5.5 psid/mA
08 * MCV116A1302  ±40 mA 69 ohms Packard 4.2 psid/mA
09 MCV116A1501  ±20 mA 643 ohms MS 12.6 psid/mA
10 * MCV116A3203  ±220 mA 16/19 ohms Packard (2) 0.78 psid/mA
14 MCV116A1101  ±100 mA 23 ohms MS 2.4 psid/mA
15 MCV116A3201  ±220 mA 16/19 ohms MS 0.78 psid/mA
16 MCV116A1203  ±160 mA 16/19 ohms Packard (2) 1.47 psid/mA
17 MCV116A1201  ±160 mA 16/19 ohms MS 1.47 psid/mA
18 MCV116A1102  ±100 mA 23 ohms Packard 2.4 psid/mA
19 MCV116A1502  ±20 mA 643 ohms Packard 12.6 psid/mA
20 MCV116A3214  ±220 mA 16/19 ohms Deutsch 0.78 psid/mA
21 MCV116A3100  ±150 mA 23 ohms No connector 1.15 psid/mA
22 MCV116J1407  Special, contact Danfoss
23 MCV116A1214  ±160 mA 16/19 ohms Deutsch 1.47 psid/mA
24 MCV116A1315  ±40 mA 69 ohms No connector 4.1 psid/mA
25 MCV116A1216  ±160 mA 16/19 ohms Deutsch 1.47 psid/mA

* 1.25, 2.5, and 5.0 gpm only.

% LAP SPLIT
MODEL CODE % LAP SPLIT

0 Line-to-line 50%
1 Standard overlap, 50%
2 Standard overlap, 2%
3 Heavy overlap, 50%
4 Heavy overlap, 2%

1

% of supply pressure at C1 and C2 when servo valve
is at null.

1

TYPICAL APPLICATIONS

Air cargo loading

Motion simulators

Asphalt pavers

Saw setworks positioners

Concrete pavers

Manipulator arms / industrial robots

Milling machines

Soil stabilizers

Material mixing machinery

Synchronized knife carriage servodrives

Edger in feed board positioners

Paper mill machinery

Injection molding machinery

Platform leveling

Edge guide control machinery

Product testing machinery

Marine deck machinery

Rocket motor testing equipment

Oil exploration equipment

2

For steering applications,
contact Danfoss

BLN-95-9061-4

TECHNICAL DATA

3

3

3

3

• Electric current in torque motor coil creates a magnetic
torque on armature

• Armature/flapper rotates about torsion pivot

• Flapper repositions towards one nozzle, which creates a
differential pressure between P1 and P2

• Each spool moves in the same direction opening the
supply )Ps) to output (C1 or C2) on one spool and the
output (C1 or C2) to return (PT) on the other spool

• Differential pressure between P1 and P2 causes the
spools to move against the centering springs until the
spring force balances with the differential pressure

• Control pressure (PC1 or PC2) reflected to the flapper
produces torque on the flapper in opposition to the
magnetic torque on the armature

DIMENSIONS

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CAUTION

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NULL ADJUST ACCESS

• As the pressure torque on the flapper becomes equal to
the magnetic torque on the armature, the flapper moves
away from the closed nozzle to an equilibrium position
producing a steady-state control pressure (PC1 or PC2)
on the ends of each valve spool

• Each valve spool stops at a position where the control
pressure force on the end of each valve spool equals the
spring force on each valve spool

• Therefore, valve spool position is proportional to input
current and, with a constant pressure drop across the
spool meter-in and meter-out edges, the flow rate to the
load is proportional to spool position

MANUAL OPERATOR

Silicone oil is present and
may drip when null is
adjusted. Utilize #3/32
Allen Wrench to adjust.

3/8 O.D. TUBE

FITTING O-RING,

PORT PER SAE - J514

9/16 - 18 UNF (2 - PL)

PLUGS INSTALLED

EXTERNAL

PILOT DRAIN

ON "D" MODEL ONLY

.312 DIA

.566 O.D.

O-RING

(4-PL)

184,15

(7.32)

11,43

(.45)

C1

PT

PS

C2

19,05

(.75)

157,99

(6.22)

8,89
(.35)

34,93

(1.375)

38,1

(1.50)

53,09
(2.09)

55,37
(2.18)

BLN-95-9061-4

38,1

(1.50)

76,2

(3.00)

99,06
(3.90)

1428B

Dimensions of the KVF in Millimeters (Inches).

3