Festo H-QS-4 Pneumatic Check Valve

Technical Overview

An ultra-lightweight (5.3g) in-line pneumatic check valve featuring anodized aluminum construction, QS-4 push-in connectors, and a 136 l/min flow rate.

Key Features

Durable, lightweight anodized aluminum housing weighing only 5.3g.
Dual QS-4 (4mm) push-in pneumatic connections for fast, secure in-line installation.
Reliable unidirectional operation across a broad -1 to 10 bar operating pressure range.
High standard nominal flow rate capacity of up to 136 l/min.
Ultra-sensitive opening differential pressure of just 0.1 bar (0.2 bar closing).
Compressed air compliance per ISO 8573-1:2010 standards.
VDMA24364-B1/B2-L LABS (PWIS) conformity for use in sensitive manufacturing lines.

Technical Specification Matrix

Parameter	Value
Valve Function	Non-return function
Pneumatic Connection 1	QS-4
Pneumatic Connection 2	QS-4
Type of Mounting	In-line installation
Standard Nominal Flow Rate	136 l/min
Operating Pressure	-1 bar to 10 bar
Ambient Temperature	0 °C to 60 °C
Housing Material	Anodised Aluminium
Housing Colour	Black
Min. Differential Pressure (Opening)	0.1 bar
Min. Differential Pressure (Closing)	0.2 bar
PWIS Conformity	VDMA24364-B1/B2-L
Physical Weight (kg)	0.01
Dimensions L x W x H (cm)	0 x 0 x 0

Industrial Applications

1. Pneumatic Gripper Pressure Maintenance

Ensures that robotic end-of-arm tooling maintains a secure grip on payloads by preventing air pressure loss if the upstream supply drops unexpectedly.

Problem Solved

Prevents sudden pressure drops in end-effector lines which could cause automated grippers to prematurely release critical components.

Non-return valveQS-4 push-in136 l/min10 barGripper actuation

2. Vacuum Lifting Circuit Isolation

Safeguards multi-cup vacuum holding systems by isolating individual vacuum cups in parallel circuits, ensuring a leak in one cup doesn't break the entire system's suction seal.

Problem Solved

Avoids total system vacuum loss by isolating compromised suction cups through a rapid 0.2 bar closing differential pressure.

-1 bar rating0.2 bar closingVacuum handlingParallel pneumatic circuit

3. PWIS-Free Automated Paint Lines

Provides unidirectional air supply in automotive and sensitive coating applications without introducing paint-wetting impairment substances.

Problem Solved

Eliminates the risk of silicone or grease contamination in sensitive painting environments while maintaining stable directional air pressure.

VDMA24364-B1/B2-LPWIS conformityAnodized aluminumIn-line installation