Series K
Pneumatic Switch
Mechanism
Installation and Operating Manual
Non-Bleed
Switch For
Liquid Level
Switches
Read this Manual Before Installing
This manual provides information on the Series K
Pneumatic Switch Mechanism. It is important that all
instructions are read carefully and followed in sequence.
Detailed installation and hook-up instructions are included
in this manual.
Conventions Used in this Manual
Certain conventions are used in this manual to convey
specific types of information. General technical material,
support data, and safety information are presented in
narrative form. The following styles are used for notes,
cautions, and warnings.
Notes
Notes contain information that augments or clarifies an
operating step. Notes do not normally contain actions.
They follow the procedural steps to which they refer.
Cautions
Cautions alert the technician to special conditions that
could injure personnel, damage equipment, or reduce
a component’s mechanical integrity. Cautions are also
used to alert the technician to unsafe practices or the
need for special protective equipment or specific
materials. In this manual, a caution box indicates a
potentially hazardous situation which, if not avoided,
may result in minor or moderate injury.
Warnings
Warnings identify potentially dangerous situations or
serious hazards. In this manual, a warning indicates an
imminently hazardous situation which, if not avoided,
could result in serious injury or death.
Safety Messages
Follow all standard industry procedures for servicing elec-
trical equipment when working with or around high
voltage. Always shut off the power supply before touching
any components.
Low Voltage Directive
For use in Installations Category II, Pollution Degree 2.
If equipment is used in a manner not specified by the
manufacturer, protection provided by equipment may
be impaired.
Notice of Copyright, and Limitations
Copyright © 2010 Magnetrol International, Incorporated.
All rights reserved.
Magnetrol reserves the right to make changes to the
product described in this manual at any time without
notice. Magnetrol makes no warranty with respect to the
accuracy of the information in this manual.
Warranty
All Magnetrol mechanical level and flow controls are war-
ranted free of defects in materials or workmanship for five
full years from the date of original factory shipment.
If returned within the warranty period; and, upon factory
inspection of the control, the cause of the claim is
determined to be covered under the warranty; then,
Magnetrol will repair or replace the control at no cost to the
purchaser (or owner) other than transportation.
Magnetrol shall not be liable for misapplication, labor
claims, direct or consequential damage or expense arising
from the installation or use of equipment. There are no
other warranties expressed or implied, except special
written warranties covering some Magnetrol products.
Quality Assurance
The quality assurance system in place at Magnetrol guar-
antees the highest level of quality throughout the
company. Magnetrol is committed to providing full cus-
tomer satisfaction both in quality products and quality
service.
Magnetrol’s quality assurance system is
registered to ISO 9001 affirming its
commitment to known international
quality standards providing the
strongest assurance of product/service
quality available.
42-686 Series K Pneumatic Switch Mechanism
1.0
Description
The Series K is a non-bleed pneumatic switch. It incorpo-
rates a three-way pneumatic valve assembly, actuated by a
magnet swing carriage. Mechanisms are available as an
option for most Magnetrol liquid level controls.
2.0
Technology
Magnetic force and the lever mechanism transmit move-
ment from the pressure vessel to the pneumatic valve.
Figure 1 shows the position of the attraction sleeve and
magnet when the liquid level is such that the attraction
sleeve is below the field of the magnet. In this position, the
flapper has been drawn away from the valve rod, permitting
the inlet air or gas to flow to a pneumatic operator. Inlet air
pressure against the ball allows the ball to seal off the
exhaust outlet.
Figure 2 shows the position of the attraction sleeve and the
magnet when the liquid level has risen, causing the attrac-
tion sleeve to attract the magnet against the enclosing tube.
In this position, the flapper actuates the air valve, closing
the supply inlet and opening the exhaust port, which
reduces the pressure in the operator to atmospheric. This
action, “close” on high, is reversible to “open” on high with
two simple adjustments (refer to page 4).
NOTE: In order to protect the switch assembly from contaminants,
filtered and dried gas/air supply is recommended.
Non-magnetic
enclosing tube
R
Pivot
D
Upper
shoulder
screw
Reverse link
position for
opposite action
Actuating link
Lower shoulder
screw
Non-magnetic
enclosing tube
R
Pivot
Upper
shoulder
D
screw
Reverse link
position for
opposite action
Actuating link
Lower shoulder
screw
Magnet (swing
in position)
Attraction sleeve
Flapper
adjustment screw
Air valve
Air supply
open position
To operator
Flapper
Exhaust
closed
Falling
level
Pivot
Attraction sleeve
Flapper
adjustment screw
Air valve
Air supply
closed position
To operator
Flapper
Exhaust
open
Pivot
Magnet (swing
out position)
Rising
level
Figure 1
Attraction sleeve below field of magnet
Figure 2
Attraction sleeve in field of magnet
42-686 Series K Pneumatic Switch Mechanism
1
3.0
Enclosing tube
Reversing Pilot Action
Reverse position
Direct position
Upper shoulder
screw
Frame screw
Fall-out stop
Magnet Tab
Actuator
link
Housing
base
All Series K Pneumatic Switch Mechanisms are shipped
from the factory in the direct (close) position at high level.
They can be field modified for the reverse (open) position
by following the steps below:
1. The action can be reversed by first removing the upper
shoulder screw from the actuator link and moving it from
the direct (D) position to the reverse (R); refer to Figure 3.
2. Loosen the screw that positions the spring bracket and
move it from the direct (D) position to the reverse (R) posi-
tion; refer to Figure 4.
3. Fasten screw securely.
The switch is now setup for reverse action.
Enclosing
tube nut
Locking screw
4.0
Figure 3
Locating Air Line Connection
Caution:
Instrument is designed for dry air/gas service.
The housing base may be rotated a full 360° for your con-
venience in connecting the air supply.
1. Loosen both the special locking screw above the enclosing
tube nut and the frame screw. Refer to Figure 3.
2. Rotate the entire base to the desired position.
3. Tighten both the locking screw and the frame screw.
4.0.1 Remove complete mechanism
Enclosing tube
Direct
position
Spring
bracket
Reverse
position
Fall-out spring
1. Disconnect air line from air line adapter.
2. Loosen both the special locking screw, above the enclosing
tube nut, and the frame screw approximately 3 to 4 turns.
Refer to Figure 3.
3. Lift the entire base straight up and off the enclosing tube.
⁄
4
" NPT Air line
inlet connection
1
1
⁄
4
" NPT Outlet
connection
Figure 4
2
42-686 Series K Pneumatic Switch Mechanism
5.0
Preventive Maintenance
5.0.1 Nozzle cleaning
Enclosing tube
To clean the nozzle, follow the steps below:
1. Unscrew and remove the adapter. Refer to Figure 5.
Caution:
Do not lose the ball which will drop out when the adapter
is removed.
Socket set
screw
1
⁄
16
" Allen
wrench
Air line
adapter
Ball
Nozzle
Flapper
Actuating rod
Figure 5
2. The ball and actuating rod will now fall out when the
switch is tipped.
3. Unscrew the socket set screw with a
1
⁄
16
" Allen wrench. This
will prevent damage to the flapper when performing step 4.
4. Insert a
1
⁄
16
" diameter wire into the nozzle from the air line
connection side. Refer to Figure 6. The wire may be moved
back and forth to clean the opening of any accumulated
matter.
5. Reassemble the actuating rod, ball, and adapter; insert into
nozzle. Refer to Figure 5.
6. Securely tighten the air line adapter.
7. Readjust the flapper to its original position; refer to Nozzle
Flapper Readjustment procedure.
5.0.2 Nozzle flapper readjustment
Magnet
(yellow
or red
dot)
Enclosing tube
1. Connect an air line to the adapter.
2. Pressurize the air line.
3. Adjust the flapper with the socket set screw for the desired
action:
Direct Action
A. Hold the magnet against the enclosing tube.
B. Adjust the socket set screw with a
1
⁄
16
" Allen wrench until
the air flow stops, plus an extra one-eighth turn.
Reverse Action
A. Hold the magnet tab against the fall out stop. Refer to
Figure 3.
B. Adjust the socket set screw with a
1
⁄
16
" Allen wrench until
the air flow stops.
4. Manually actuate the switch under pressure to assure its cor-
rect actuation. The unit is now ready for service.
5. Operate control at normal process conditions to verify
adjustments.
Socket set screw
1
⁄
16
" Diameter wire
Flapper
Nozzle
Figure 6
42-686 Series K Pneumatic Switch Mechanism
3
京公网安备 11010802033920号
EEWORLD
