Intake Air Shut-off Valve

Model 4261M

Overview

Diesel run-away is a potential problem that can

cause damage to equipment. A diesel engine
can run away and self destruct on hydrocarbon
vapors, even if the engine’s primary source of fuel
is taken away.
An air intake shut-off valve is recommended
for diesel engines which have a possibility of
encountering hydrocarbon vapors.

4261M Intake Air Shut-off Valve

Typical applications Operation

l Oil field - drilling rigs, mud trucks, wireline The 4261M Intake Air Shut-off Valves from AMOT
feeders, crude haulers, welders and other use the best available technology to shut down a
machinery run-away diesel by positively choking off engine
intake air. They are 2.8, 3.5, 5.5 and 8.0 inch
l On/off shore - compressors, gen sets, fire diameter, remotely operated butterfly valves
pumps and welders designed to be installed in the engine intake.
l Construction - ideal for trenchers, gas co When a condition is detected that could damage
service trucks, sewage pumpers the engine (over temperature, over speed), the
valve trips shut, closes off the air intake and
l Transporters - aircraft refuelers and all stops the engine to prevent serious damage.
combustable chemicals or hazardous waste
Figure 1 illustrates a typical installation of a
safety control actuated butterfly valve. In the
event of a 4110 Speed Sensing Valve detecting
Key features and benefits an over speed condition, it vents the control oil
pressure. The drop in pressure to the 4261M
l Compact design - easy, low cost installation trips the valve to close the engine air intake. The
l Corrosive resistant, anodized aluminum and orifice is installed to ensure that pressure drops
stainless steel construction are felt at the valve in large volume systems.

l Use stand-alone or in complete runaway All sizes of valve have a choice of actuator
shut-down system operation: Electric Solenoid operated;
Hydraulic operated; Pneumatic operated;
l Remote re-set facility - flexible control and Pneumatic/Manual operated.
l Best available technology - ‘Butterfly Valve’
design

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 www.amot.com
 Intake Air Shut-off Valve - Model 4261M
Typical applications
Hydromechanical Automatic System (Safety Control)
SAFETY CONTROL
ACTUATED VALVE
l Engines without electricity/air supply
MODEL 426M0*A041-AA
l Offshore engines

System trips on loss of lube oil pressure. The

overspeed valve will vent off oil pressure to trip
system.
Model 4261M0 A041-AA
Hydromechanical safety controlled valve (trips
on loss of pressure).

LUBE OIL ORIFICE

PRESSURE

Figure 1
VENT
4110
OVERSPEED
SENSING
VALVE

Automatic, Pneumatic System with Manual Override

l Offshore
PULL TO RESET l Hazardous areas
PUSH TO STOP

M
PNEUMATIC ACTUATOR
4261M0*A021-AA Three-way air valve is pulled to pressurise
VENT 4057 (Trips on system and open the 4261M valve. During a
3-WAY AIR pressure loss)
3 VALVE run-away, overspeed sensing valve vents off
AIR SUPPLY
30-50 PSI 1
2 air pressure to trip the valve. Shut down can
also be initiated by pushing three-way air valve
knob.

ORIFICE Model 4261M0 A021-AA (air to run)

4261M0 A025-AA (air to close)
Pneumatic actuator
Spring return operated 4261M
VENT

4110
OVERSPEED
SENSING
VALVE

Figure 2

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 page 2
 Intake Air Shut-off Valve - Model 4261M
Typical applications continued
Electro/Pneumatic Automatic System (Manual Pneumatic)

l Tank trucks Magnetic pick-up (or alternator) sends RPM

signal to speed switch. When RPM indicates
l Oil field trucks
run-away condition, speed switch trips,
l Construction machinery activating 3-way solenoid valve and closing
intake air shut-off valve. Protected toggle
l Industrial engines
switch activated test circuit allows systems to
be tested at 67% of run-away speed.

Model 4261M0 A027-AA

Manual pneumatic operated 4261M

Optional airline

FigureCable
3

Model 4261M0*A027-AA
Electronic Manual System

l Fire trucks The 4261 is manually cocked to run the engine

and the solenoid built into it must be energised
l Manned construction equipment
to shut down. This system is widely used even
though it is not fail safe. Wire breakage or loss
of electrical power will disable the system, so
frequent testing by actuation is recommended.
-
+
Model 4261M0 A127-AA
Model 4261M0*A172-AA Electric solenoid operated 4261M

Figure 4

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 page 3
 Intake Air Shut-off Valve - Model 4261M
Specification
Standard materials Valve body and disc Anodized aluminium
Valve shafts Stainless steel
Seals Nitrile or Viton
Safety control operator Anodized aluminum
Pneumatic cylinders Aluminum and stainless steel
Brackets Plated steel
Maximum intake Nitrile seals (standard) 93°C 200°F
air temperature Viton seals 149°C 300°F
Valve Bore Size 2.75” valve size 61mm 2.4” bore size
3.5” valve size 74mm 2.9” bore size
5.5” valve size 125mm 4.9” bore size
8.0” valve size 191mm 7.5” bore size
Net weight 2.75” valve size 1.4 - 1.8kg 3.1 - 4.0lbs
(inc. operator) 3.5” valve size 1.4 - 1.8kg 3.1 - 4.0lbs
5.5” valve size 1.8 - 2.2kg 4.0 - 4.9lbs
8.0” valve size 3.6 - 4.1kg 7.9 - 9.0lbs
Pneumatic rotary Minimum actuation pressure 310kPa 45psi
actuator Recommended actuation pressure 414 - 552kPa 60 - 80psi
Maximum actuation pressure 690kPa 100psi
Manual/pneumatic Minimum actuating pressure 207kPa 30psi
cylinder operator Maximum working pressure 1380kPa 200psi
Mechanical pull to release 67N 15lbs
Hydraulic operator Adjustable trip pressure 34 - 275kPa 5-40psi falling
Max. pressure on diaphragm 1170kPa 170psi
Electric solenoid 12VDC & 24VDC 96W
operators Maximum coil temperature 175°C 350°F
(intermittent duty) Duty cycle 12% ie 75 secs (max) on-time
followed by 540 secs (min) off-time

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 page 4
 Intake Air Shut-off Valve - Model 4261M
Dimensions
Electric Solenoid Hydraulic Safety Control

Rotary/Pneumatic Manual/Pneumatic

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 page 5
 Intake Air Shut-off Valve - Model 4261M
How to order
Use the tables below to select the unique specification of your Model 4261M Air Shut-off Valve:
Example 4261M 03 A 0 21 -AA Code Description

Basic Model Code 4261M Model

mm inches
02 71.12 2.8
03 88.9 3.5
Valve Size
05 139.7 5.5
08 203.2 8.0

Seal Material A Aluminum and Nitrile/Buna N

Standard for all actuators except electric actuator options 71&72, no

0
position switch or terminal box
1 Standard for electric actuator 71&72; no position switch or terminal box
Operators 2 Limit switch installed; for electric actuator options 71&72 only
3 Terminal box installed; for electric actuator options 71&72 only
Limit switch and terminal box installed; for electric actuator options 71&72
4
only

00 Slave operator for use on 'V' engines

11 No operator, return spring or lever fitted
21 Pneumatic rotary actuator, pressurize to run, spring return to close. NPT
threads
22 Pneumatic rotary actuator, pressurize to run, spring return to close. BSP
PL
25 Pneumatic rotary actuator, pressurize to close, spring return to open. NPT

26 Pneumatic rotary actuator, pressurize to close spring return to open. BSP

PL
Valve Actuator
27 Manual/pneumatic cylinder manually cocked to run, pressurize or manual
trip to shut down. NPT thread
28 Manual/pneumatic cylinder, manually cocked to run, pressurize or manual
trip to shut down. BSP PL
41 Safety control, NPT thread
45 Safety control, BSP PL
71 Electric Solenoid, 12 VDC, manually cocked to run, energize to shut down.

72 Electric Solenoid, 24 VDC, manually cocked to run, energize to shut down.

-AA Standard
Special Requirements
Please contact AMOT for any special requirements.

Accessories
A range of accessories can be purchased along side your 4261M valve:
Electronic Speed Switch 8210K 3-way Logic Valves 4057
see Datasheet_8210K_Electronic_Speed Switch see Datasheet_4057_3-way_valve

Mechanical Overspeed Sensing Valve 4110 Magnetic Pick-up (with boot) 11408X
see Datasheet_4110_Overspeed_Sensing_Valve see Datasheet_11408X_Magnetic_Pickup

Datasheet_4261M_Air_Shutoff_Valve_0119rev2 page 6
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USA Shanghai 201801
China
Tel +1 (281) 940 1800
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Europe, Middle East and Africa

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Suffolk, IP33 3SZ
England
Tel +44 (0) 1284 715739
Fax +44 (0) 1284 760256
Email sales@amot.com

AMOT Controls GmbH

Rondenbarg 25
22525 Hamburg
Germany
Tel +49 (0) 40 8537 1298
Fax +49 (0) 40 8537 1331
Email germany@amot.com

www.amot.com
Datasheet_4261M_Air_Shutoff_Valve_0119rev2