Brochure

MK-88xx Series, MK-89xx Series
Valve Actuators, Proportional
Model Chart
Specifications
Accessories
Proportional pneumatic actuator with 100 in.
2
(645 cm
2
) effective area. MK-88xx Series used to
control 2-1/2 in. through 4 in. valves requiring 1 in.
stroke. MK-89xx Series used to control 5 in. and 6 in.
valves requiring 2 in. nominal stroke. Used with
VB-931x and discontinued VB-921x, VB-922x valves.
Features:
• Heavy duty aluminum construction.
• Large diaphragm area provides the required force to
modulate large valves.
• Valve stroke indicated in 1/8 in. increments.
Model No.
Nominal Spring Range
a
a
Nominal (no load) spring ranges are based on maximum 1 in. (25.4 mm) or 2 in. (50.8 mm) stroke.
Nominal Stroke
For Use with
Valve Bodies
psig kPa in. mm
MK-8801 3 to 8 21 to 55
125.4
2-1/2 to 4 in.
VB-9213
VB-9223
VB-9313
MK-8811 5 to 10 34 to 69
MK-8821 8 to 13 55 to 90
MK-8901 3 to 8 21 to 55
250.8
5 in. and 6 in.
VB-9213
VB-9223
VB-9313
MK-8911 5 to 10 34 to 69
MK-8921 8 to 13 55 to 90
Construction
Housing Die cast aluminum.
Diaphragm Replaceable beaded molded neoprene.
Stroke Refer to Model Chart.
Spring Retracts actuator shaft and raises valve stem on loss of air pressure.
Nominal spring range Refer to Model Chart.
Starting point Adjustable r1 psi (7 kPa).
Maximum air pressure 30 psig (207 kPa).
Ambient temperature limits
Shipping -40 to 220qF (-40 to 104qC).
Operating -20 to 220qF (-29 to 104qC).
Air connection 1/8 in. FNPT.
Valve linkage Order separately AV-496-0-0-1.
Valve stroke position indication 1/8 in. (3 mm) increments.
Mounting In any upright position with actuator head above 45q of the center line of the valve body.
Dimensions
MK-88xx Series 11-3/4 H x 10-1/2 W x 10-1/2 D in. (298 x 267 x 267 mm).
MK-89xx Series 12-3/4 H x 10-1/2 W x 10-1/2 D in. (342 x 267 x 267 mm).
Model No. Description
AK-42309-500 Positive positioner with linkage.
TOOL-095-1 Pneumatic calibration tool kit.
Maintenance Parts
PNV-202 Diaphragm (2 required).
PNV-312 Rolling diaphragm.
MK
-
88
x
Series
,
MK-89
x
Series
MK-88xx Series
MK-89xx Series
F-27383-1 © Copyright 2006 TAC. All Rights Reserved. 61