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Rotork ‘E’ range of process control actuators
Vacuum
News
by the manufacturers to have a lower air consumption other types of pneumatic-motor conveyors.
experience and, say the company, should give considerable weight and cost savings through a more precise matching of actuators to specific valve operating conditions and characteristics.
than
The conveyor was designed primarily for the food industry and, with hygiene in mind, the endless belt is completely removable to facilitate thorough cleaning. This is made possible by a patented cantilevered construction. The belt part of the conveyor is supported on one side only, and a hinged end section relieves the tension on the drive drum, allowing the belt to be slipped over the unhindered side of the cantilever. Another advantage of the hinged end section envisaged by Turbo Tools, is for access in congested production situations where, for example, a series of satellite conveyors feed a main flow line. The ability to ‘open-up’ the end of a satellite conveyor would give greater maintenance and operator freedom.
The ‘E’ range design is a continuous modulating actuator which requires only a three-phase electricity supply and an electronic control signal, thereby considerably simplifying control valve system installations when electronics instrumentation is used. The basic operating mechanism is a hydraulic piston acting against a return spring, and the original range was designed to achieve a relatively balanced output, i.e. about the same net force for the power stroke as for the spring return.
Being entirely air-operated, the conveyor also overcomes the hazards always present with electrics when using materials of low flash-points, and it is completely safe in wet or damp conditions. Other features of the conveyor include, a 235 mm (9 in) height adjustment on the cantilever supports, stainless-steel surfaces, and heavy-duty castors for mobility. At present, the conveyor is being built to order, to required sizes up to a belt length of 9 m (30 ft) and a belt width of 610 mm (24 in). The pneumatic drive operates on a simple and novel principle, using only two cylinders (see diagram).
A simplified system
which
drawing
of Turbo
uses Schrader
Tools’ pneumatic
conveyor
drive
equipment. Typical balanced
The cylinders are attached to a sprung chain mechanism and carefully synchronised so that their reciprocating motion continuously drives a ratchet. This in turn, rotates the conveyor drum via a continuous chain.
The pneumatics were supplied by the Leeds branch of Schrader official stockists, Economatics Ltd. Turbo Tools Ltd
Rotork
‘E’ range
number
34 on Reader
of process
control
Enquiry
Service
The additions, which nearly double the choice of thrust and stroke combinations, result from three years’ applications 522
card
actuators
Five new sizes have been added to the ‘E’ range of electrohydraulic modulating process control actuators manufactured Rotork Controls Ltd. valve control specialists of Bath, Avon.
globe
‘E’ range
actuators
fitted
values for application
to Hymatic
in a Dutch
8 in.
refinery.
There are, however, many control valves which need a greater force in one direction than the other; so, by varying the strength of the return spring in the actuator, Rotork have been able to produce additional units providing either for increased hydraulic force with reduced spring force, or vice-versa.
Speed is variable up to 25 ft min-r (7.6 m min-‘) by means of an adjustable balanced needle valve-designed by Turbo Tools-which works off the exhausts of the two cylinders.
Circle
Rotork
by
The full range now comprises eleven actuators providing for operating strokes between 1.57 in (40 mm) and 6 in (152 mm) with a choice of balanced or biased power/spring thrust for those strokes in which experience has shown this to be desirable. Typical applications where the new versatility in specification will be of benefit are butterfly valves, which usually require a higher opening force against line pressure tending to close the valve, and single-seated globe valves for which the maximum force direction will vary, depending on whether line pressure is below or above the seat. Typically, a valve requiring, say, a thrust of 4,000 Ibs in one direction and only 800 Ibs in the other-over a 3 ins stroke-would previously have needed E43, with a weight
Vacuum
News
Table 1. Rotork ‘E’ range process control
actuator
performance *
data *
*
*
*
E21
ES41
E31
E41
E42
E43
E51
E61
E52
E53
El1
in
2
1.57
2.55
3.15
3.15
3.15
4
5
6
6
6
mm
51
40
65
80
SO
80
102
127
152
152
152
lbf
950
2700
1570
2700
1810
880
4850
8300
2420
2420
15400
kN
4.23
12.02
6.99
12.02
8.05
3.92
21.58
36.94
10.77
10.77
68.53
lbf
700
2440
1450
1160
2850
4810
5040
9320
5040
16700
17190
kN
3.12
10.86
6.45
5.16
12.68
21.4
22.43
41.47
22.43
74.32
76.50
lb
71
152
88
152
142
127
360
570
370
370
920
kg
32
69
40
69
65
58
164
260
168
168
420
in/set
.13
-07
.lO
.07
.07
-07
-22
.22
.22
.22
.22
1.8
1.8
5.6
5.6
5.G
5.6
5.6
STROKE
SPRING THRUST
POWER
APPROX WEIGHT
NET
APPROX AVERAGE SPEED
mm/s=
3.3
1.8
2.5
1.8
-
Showing the new, extended Rotork ‘E’ range of process control actuators. The five sizes marked differential spring/power thrust for more economic motorisation of certain types and applications fills a previous gap in the operating stroke between the E31 and E51.
saving of 65% and reduction in cost of about 44%. Valves requiring a 6 in stroke would previously have needed the largest E71 actuator, whereas now many can be powered by the E52 and E53 sizes with equally significant savings. Rotork Controls Ltd Circle number
35 on Reader
Enquiry
Service
card
Key actuator To give design engineers an additional safety factor on pneumatic circuits, Schrader Pneumatics are now offering key-actuated versions of their midget spool and midget poppet valves. Valves are supplied with a removable key (plus a duplicate) which prevents the operation-or closedown-of a circuit or machine by any unauthorised personnel. The key locks the valve in the open position. The midget spool version is available with either a three or four-way valve (3/2 or 5/2) ; the midget poppet version is three-way only (3/2). Port size in all cases is l/8 in BSP. The actuators are designed for panel mounting and have a 1.3/l 6 in x 26 Whitworth neck thread with a hexagonal nut. Schrader Circle number
36 on Reader
Enquiry
gases. With this system users can now effectively own mixtures at their own desired concentrations.
The mass flowmeters can be directly calibrated for any gas, or if user contemplates blending different gases, air calibration can be supplied, and the operator would apply a simple conversion factor. The gas blending systems are packaged in Nuclear Instrument Modules (NIM) that become part of a NIM frame suitable for mounting as a standard 8: in x 19 in relay rack panel. Applications include the instantaneous blending of calibration gases for gas chromatographs, sputtering processes, and semiconductor manufacture. Another use is the manufacture of controlled sample atmospheres for air pollution studies. It likewise eliminates storage decay of preblended mixtures and the storage of cylinders of different concentrations. Teledyne Circle number
37 on Reader
Hastings-Raydist
Enquiry
Service
card
card
Digital Gas blending
blend their
The system is inherently a mass flow system and requires no correction for pressures and temperature changes. Changes in the blending ratios are made by selecting suitable range transducers and by adjusting a single 0 to 100% counter dial located on the control panel.
Pneumatics Service
have been added to provide of valves. The E41 size also
l
system
Teledyne Hastings-Raydist of Hampton, Virginia, U.S.A. announces the Hastings Gas Blending System for instantaneous blending of gases with blend ratios from 1 : 1 to ppm capability with typical accuracy of 2%. The system is a combination of their proven reliable linear mass flowmeters and automatic flow controller. It has been adapted to accept and compare the signals from two linear mass flowmeters, each monitoring a separate gas line. The controller adjusts automatically to discharge the desired percentage of each of two
display
thermocouple
gauge
controller
Detek Sensors, Inc. of Cupertino, California has introduced a digital display thermocouple gauge controller, to supply and to operate four thermocouple gauge tubes sequentially. The controller, designated QUAD TC-100, is a first in the industry. Models are available with optional BCD output and alarm levels. The controller operates response thermocouple The QUAD TC-100
Detek’s Model TG-6343 super fast gauge tube (response time, less than 0.1 s).
is a half-rack
mounting
unit. Detek Sensors Inc
Circle number
38 on Reader
Enquiry
Service
card 523
News
by the manufacturers to have a lower air consumption other types of pneumatic-motor conveyors.
experience and, say the company, should give considerable weight and cost savings through a more precise matching of actuators to specific valve operating conditions and characteristics.
than
The conveyor was designed primarily for the food industry and, with hygiene in mind, the endless belt is completely removable to facilitate thorough cleaning. This is made possible by a patented cantilevered construction. The belt part of the conveyor is supported on one side only, and a hinged end section relieves the tension on the drive drum, allowing the belt to be slipped over the unhindered side of the cantilever. Another advantage of the hinged end section envisaged by Turbo Tools, is for access in congested production situations where, for example, a series of satellite conveyors feed a main flow line. The ability to ‘open-up’ the end of a satellite conveyor would give greater maintenance and operator freedom.
The ‘E’ range design is a continuous modulating actuator which requires only a three-phase electricity supply and an electronic control signal, thereby considerably simplifying control valve system installations when electronics instrumentation is used. The basic operating mechanism is a hydraulic piston acting against a return spring, and the original range was designed to achieve a relatively balanced output, i.e. about the same net force for the power stroke as for the spring return.
Being entirely air-operated, the conveyor also overcomes the hazards always present with electrics when using materials of low flash-points, and it is completely safe in wet or damp conditions. Other features of the conveyor include, a 235 mm (9 in) height adjustment on the cantilever supports, stainless-steel surfaces, and heavy-duty castors for mobility. At present, the conveyor is being built to order, to required sizes up to a belt length of 9 m (30 ft) and a belt width of 610 mm (24 in). The pneumatic drive operates on a simple and novel principle, using only two cylinders (see diagram).
A simplified system
which
drawing
of Turbo
uses Schrader
Tools’ pneumatic
conveyor
drive
equipment. Typical balanced
The cylinders are attached to a sprung chain mechanism and carefully synchronised so that their reciprocating motion continuously drives a ratchet. This in turn, rotates the conveyor drum via a continuous chain.
The pneumatics were supplied by the Leeds branch of Schrader official stockists, Economatics Ltd. Turbo Tools Ltd
Rotork
‘E’ range
number
34 on Reader
of process
control
Enquiry
Service
The additions, which nearly double the choice of thrust and stroke combinations, result from three years’ applications 522
card
actuators
Five new sizes have been added to the ‘E’ range of electrohydraulic modulating process control actuators manufactured Rotork Controls Ltd. valve control specialists of Bath, Avon.
globe
‘E’ range
actuators
fitted
values for application
to Hymatic
in a Dutch
8 in.
refinery.
There are, however, many control valves which need a greater force in one direction than the other; so, by varying the strength of the return spring in the actuator, Rotork have been able to produce additional units providing either for increased hydraulic force with reduced spring force, or vice-versa.
Speed is variable up to 25 ft min-r (7.6 m min-‘) by means of an adjustable balanced needle valve-designed by Turbo Tools-which works off the exhausts of the two cylinders.
Circle
Rotork
by
The full range now comprises eleven actuators providing for operating strokes between 1.57 in (40 mm) and 6 in (152 mm) with a choice of balanced or biased power/spring thrust for those strokes in which experience has shown this to be desirable. Typical applications where the new versatility in specification will be of benefit are butterfly valves, which usually require a higher opening force against line pressure tending to close the valve, and single-seated globe valves for which the maximum force direction will vary, depending on whether line pressure is below or above the seat. Typically, a valve requiring, say, a thrust of 4,000 Ibs in one direction and only 800 Ibs in the other-over a 3 ins stroke-would previously have needed E43, with a weight
Vacuum
News
Table 1. Rotork ‘E’ range process control
actuator
performance *
data *
*
*
*
E21
ES41
E31
E41
E42
E43
E51
E61
E52
E53
El1
in
2
1.57
2.55
3.15
3.15
3.15
4
5
6
6
6
mm
51
40
65
80
SO
80
102
127
152
152
152
lbf
950
2700
1570
2700
1810
880
4850
8300
2420
2420
15400
kN
4.23
12.02
6.99
12.02
8.05
3.92
21.58
36.94
10.77
10.77
68.53
lbf
700
2440
1450
1160
2850
4810
5040
9320
5040
16700
17190
kN
3.12
10.86
6.45
5.16
12.68
21.4
22.43
41.47
22.43
74.32
76.50
lb
71
152
88
152
142
127
360
570
370
370
920
kg
32
69
40
69
65
58
164
260
168
168
420
in/set
.13
-07
.lO
.07
.07
-07
-22
.22
.22
.22
.22
1.8
1.8
5.6
5.6
5.G
5.6
5.6
STROKE
SPRING THRUST
POWER
APPROX WEIGHT
NET
APPROX AVERAGE SPEED
mm/s=
3.3
1.8
2.5
1.8
-
Showing the new, extended Rotork ‘E’ range of process control actuators. The five sizes marked differential spring/power thrust for more economic motorisation of certain types and applications fills a previous gap in the operating stroke between the E31 and E51.
saving of 65% and reduction in cost of about 44%. Valves requiring a 6 in stroke would previously have needed the largest E71 actuator, whereas now many can be powered by the E52 and E53 sizes with equally significant savings. Rotork Controls Ltd Circle number
35 on Reader
Enquiry
Service
card
Key actuator To give design engineers an additional safety factor on pneumatic circuits, Schrader Pneumatics are now offering key-actuated versions of their midget spool and midget poppet valves. Valves are supplied with a removable key (plus a duplicate) which prevents the operation-or closedown-of a circuit or machine by any unauthorised personnel. The key locks the valve in the open position. The midget spool version is available with either a three or four-way valve (3/2 or 5/2) ; the midget poppet version is three-way only (3/2). Port size in all cases is l/8 in BSP. The actuators are designed for panel mounting and have a 1.3/l 6 in x 26 Whitworth neck thread with a hexagonal nut. Schrader Circle number
36 on Reader
Enquiry
gases. With this system users can now effectively own mixtures at their own desired concentrations.
The mass flowmeters can be directly calibrated for any gas, or if user contemplates blending different gases, air calibration can be supplied, and the operator would apply a simple conversion factor. The gas blending systems are packaged in Nuclear Instrument Modules (NIM) that become part of a NIM frame suitable for mounting as a standard 8: in x 19 in relay rack panel. Applications include the instantaneous blending of calibration gases for gas chromatographs, sputtering processes, and semiconductor manufacture. Another use is the manufacture of controlled sample atmospheres for air pollution studies. It likewise eliminates storage decay of preblended mixtures and the storage of cylinders of different concentrations. Teledyne Circle number
37 on Reader
Hastings-Raydist
Enquiry
Service
card
card
Digital Gas blending
blend their
The system is inherently a mass flow system and requires no correction for pressures and temperature changes. Changes in the blending ratios are made by selecting suitable range transducers and by adjusting a single 0 to 100% counter dial located on the control panel.
Pneumatics Service
have been added to provide of valves. The E41 size also
l
system
Teledyne Hastings-Raydist of Hampton, Virginia, U.S.A. announces the Hastings Gas Blending System for instantaneous blending of gases with blend ratios from 1 : 1 to ppm capability with typical accuracy of 2%. The system is a combination of their proven reliable linear mass flowmeters and automatic flow controller. It has been adapted to accept and compare the signals from two linear mass flowmeters, each monitoring a separate gas line. The controller adjusts automatically to discharge the desired percentage of each of two
display
thermocouple
gauge
controller
Detek Sensors, Inc. of Cupertino, California has introduced a digital display thermocouple gauge controller, to supply and to operate four thermocouple gauge tubes sequentially. The controller, designated QUAD TC-100, is a first in the industry. Models are available with optional BCD output and alarm levels. The controller operates response thermocouple The QUAD TC-100
Detek’s Model TG-6343 super fast gauge tube (response time, less than 0.1 s).
is a half-rack
mounting
unit. Detek Sensors Inc
Circle number
38 on Reader
Enquiry
Service
card 523