Product description
In-line flow restrictors for precise and tamper-proof gas flow control
In-Line Flow Restrictors manufactured from sintered porous metal provide accurate and fixed gas flow limitation in compressed gas systems. These devices are designed as a reliable and cost-effective alternative to traditional flow controllers, needle valves and calibrated orifices.
Installed directly in gas supply lines and distribution manifolds, in-line flow restrictors prevent excessive gas flow caused by ruptured gas lines, malfunctioning valves or failing pressure regulators. They are widely used in safety-critical and high-purity gas applications.
Operating principle
In-line flow restrictors operate using sintered porous media containing a large number of small, interconnected pathways. Gas flows through these tortuous passages, creating controlled resistance and limiting the downstream flow rate.
This flow control mechanism provides:
precise and fixed flow limitation
laminar downstream gas flow
reduced turbulence compared to single orifice devices
lower risk of particulate fouling
stable performance without moving parts
Unlike traditional single bore orifice devices, porous metal restrictors distribute flow across multiple pathways, reducing erosion, pressure spikes and plugging risk.
Material construction
In-line flow restrictors are typically manufactured with a stainless steel porous element integrated into stainless steel fittings. Alternative materials and fitting configurations are available depending on application requirements.
Key material characteristics include:
all-metal construction for durability
corrosion resistance
high mechanical strength
dimensional stability
compatibility with high purity gases
no moving parts and no power requirement
The absence of mechanical components ensures long-term reliability and tamper-proof operation.
Flow performance and operating conditions
In-line flow restrictors are calibrated for specific gases and operating pressures to ensure accurate and repeatable performance.
Typical performance characteristics include:
standard flow tolerance of approximately ±7.5% at rated pressure and gas type
downstream flow rates ranging from 1 SCCM up to 60 SLPM
operating pressures up to 110 psig (standardised to atmosphere)
sustained operating temperatures up to 450°C in inert gas applications
calibration using gases such as N2, He, H2, Air, O2 or Ar
Other gases can be correlated using nitrogen calibration data.
Typical applications
Medical gas systems
Chemical processing
Pharmaceutical production
Semiconductor manufacturing
Food and beverage processing
Aerospace applications
Leak detection systems
Chromatography equipment
Replacement of flow controllers or needle valves
OEM system integration
They are particularly suitable for inert, highly toxic and pyrophoric gases where controlled flow is critical for safety.
Features and benefits
Improved gas safety management in case of system failure
Reliable and tamper-proof fixed flow control
No moving parts and no power requirement
Laminar downstream flow
Reduced particulate fouling compared to single orifice restrictors
Prevention of pressure surges and shock
Long service life under demanding conditions
Configuration and quotation
In-line flow restrictors are supplied based on specific application parameters. To ensure correct sizing and calibration, the following information is required:
gas type and operating temperature
inlet pressure
desired downstream flow rate
downstream pressure
fitting size, type and material
Technical support is available to assist in selecting the appropriate flow restrictor configuration for your system.