V/O-3-1/8 Festo Stem Actuated Valve

Technical Overview

The Festo V/O-3-1/8 is a mechanically operated 3/2-way stem actuated valve with a monostable design, capable of being configured as normally open or normally closed. It utilizes a piston seat design and direct piloting to manage a standard nominal flow rate of 140 l/min. Constructed from anodised aluminium with NBR seals, it is suitable for operating pressures between -0.95 and 8 bar and temperatures from -10 to 60 °C. It features G1/8 pneumatic connections and is designed for through-hole mounting.

Key Features

3/2-way, monostable valve function
Mechanical stem actuation
Standard nominal flow rate of 140 l/min
Piston seat design
Direct piloting
G1/8 pneumatic connections
Anodised aluminium housing material
NBR seals

Technical Specification Matrix

Parameter	Value
Valve function	3/2-way, monostable, open/closed
Type of actuation	Mechanical
Standard nominal flow rate (standardised to DIN 1343)	140 l/min
pneumatic working port	G1/8
Operating pressure	-0.95 bar ... 8 bar
Design	Piston seat
Nominal size	3.5 mm
Type of piloting	Direct
Symbol	00991832
Operating medium	Compressed air to ISO 8573-1:2010 [-:-:-]
Note on operating and pilot medium	Lubricated operation possible (in which case lubricated operation will always be required)
LABS (PWIS) conformity	VDMA24364-B1/B2-L
Ambient temperature	-10 °C ... 60 °C
Actuating force	28 N
Actuating force, normally closed	37.53 N
Product weight	90 g
Type of mounting	With through-hole
Pneumatic connection, port 1	G1/8
Pneumatic connection, port 2	G1/8
Pneumatic connection, port 3	G1/8
Material seals	NBR
Material housing	Anodised aluminium

Industrial Applications

1. Explosion-Proof Conveyor Pallet Detection

In hazardous industrial environments like automotive paint shops or grain handling facilities where electric sparks pose an explosion risk, this mechanical valve serves as a non-electrical limit switch. Mounted at the end of a conveyor section, the moving pallet physically depresses the valve's stem upon arrival, pneumatically signaling the system to stop the belt or divert the load.

Problem Solved

Eliminates the risk of electrical ignition in ATEX zones by replacing electronic sensors with a purely pneumatic position sensing solution.

Mechanical actuation140 l/min flow ratePilot signal generationExplosion-proof sensingStem actuated

2. Safety Interlock for Pneumatic Press Guards

Used as a safety component in pneumatic pressing or ironing machines, the valve is installed so that the safety door pushes the stem in when fully closed (Normally Open configuration held closed). If the operator opens the door, the stem is released, immediately venting the pilot air and cutting off the power circuit to the press cylinder, preventing operation.

Problem Solved

Prevents accidental injury by ensuring the machine cannot cycle unless the protective guard is physically engaged, utilizing the valve's high actuating force requirement (28 N) to prevent false positives.

Safety interlockMonostable functionNormally closed logicActuating force 28 NG1/8 pneumatic connection

3. Automatic Retraction for Pneumatic Drilling Feeds

In automated drilling or machining rigs, this valve acts as the depth-stop trigger. Positioned at the target drill depth, the carriage unit strikes the valve's stem, switching the 3/2-way valve to send a reversal signal to the main cylinder's directional control valve, causing the drill to retract automatically without complex electronics.

Problem Solved

Automates the reciprocating cycle of pneumatic tools reliably in oily or wet machining environments where electronic sensors might fail due to coolant exposure.

End-of-stroke sensingPiston seat designDirect pilotingOperating pressure -0.95 ... 8 barLubricated operation