Schneider Electric MK-8801 Catalog Page

Valve Actuators, Proportional

Proportional pneumatic actuator with 100 in.2 (645 cm 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, and VB-922x valves.

) effective area. MK-88xx Series used to

MK-88xx Series, MK-89xx Series

Features:

• Heavy duty aluminum construction.

• Large diaphragm area provides the required force to

MK-88xx Series

MK-89xx Series

modulate large valves.

• Valve stroke indicated in 1/8 in. increments.

Model Chart

Model No.

MK-8801 3 to 8 21 to 55 MK-8811 5 to 10 34 to 69

MK-8821 8 to 13 55 to 90

MK-8901 3 to 8 21 to 55 MK-8911 5 to 10 34 to 69

MK-8921 8 to 13 55 to 90

Nominal (no load) spring ranges are based on maximum 1 in. (25.4 mm) or 2 in. (50.8 mm) stroke.

Nominal Spring Range

psig kPa in. mm

Nominal Stroke

125.4

250.8

For Use with

Valve Bodies

2-1/2 to 4 in.

5 in. and 6 in.

Specifications

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 ±1 psi (±7 kPa).

Maximum air pressure 30 psig (207 kPa).

Ambient temperature limits

Shipping -40 to 220°F (-40 to 104°C).

Operating -20 to 220°F (-29 to 104°C).

Air connection 1/8 in. FNPT.

Valve linkage Order separately AV-496.

Valve stroke position indication 1/8 in. (3 mm) increments.

Mounting In any upright position with actuator head above 45° 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).

VB-9213 VB-9223 VB-9313

MK-88xx Series, MK-89xx Series

Accessories

Part Number Description

AK-42309-500 Positive positioner with linkage. TOOL-095-1 Pneumatic calibration tool kit.

Linkage

AV-496 Valve linkage.

Maintenance Parts

PNV-202 Diaphragm (2 required). PNV-312 Rolling diaphragm.