Owner's manual
Specifications
Series 256 Servovalve Product Information Introduction
19
Series 256 Servovalve Performance Characteristics
Note The servovalve flow at the higher frequencies depends on many system
characteristics that are unrelated to the Model 256 Servovalve (such as
hydraulic fluid compressibility, supply and return line lengths, actuator
characteristics, and specimen characteristics).
The flow versus frequency performance curves shown in following figures
indicate the relative performance of the 256 Servovalves at various frequencies.
The curves are derived by driving the servovalve at the indicated frequency with
a sine wave control signal and ± full current to the coil. A 21 MPa (3000 psi)
pressure is supplied and there is a 7 MPa (1000 psi) pressure drop across the
servovalve.
Servovalve performance at higher frequencies is a function of variables
introduced by system components, actuator response, and specimen
characteristics.
256.25A-01
256.25A-02
256.25A-05
950
950
950
250
250
250
3.8
9.5
19
1
2.5
5
10
18
25
90
125
125
15
<10
8
10
<10
4
256.40A-01
256.40A-02
256.40A-05
256.40A-10
1500
1500
1500
1500
400
400
400
400
3.8
9.5
19
3.8
1
2.5
5
10
4
‡
9
‡
12
‡
15
‡
40
‡
75
‡
110
110
65
‡
26
‡
13
10
20
‡
8
‡
4
3.5
MODEL*RATED FLOW PILOT FLOW FULL FLOW
F
REQUENCY
90º PHASE
S
IGNAL
†
SPOOL STROKE RISE TIME (T
R
)
(
MILLISECONDS)
L/
MIN GPM L/MIN GPM HZ HZ 90% OPEN 10% OPEN
* Performance information is provided for the models listed. Contact MTS for performance information
for Models 256.18D and 256.xxB.
† At 10% spool stroke.
‡ These are estimated values. All other values are typical.