When working with potentially hazardous fluids or gasses, safety is paramount. Unexpected line, hose or fitting failures can lead to significant risks to personnel, equipment and the environment. 

Malema’s M-VF Series Excess Flow Valve offers a robust and reliable solution for automatic shut-off in such critical situations.

These safety excess flow valves are specifically engineered to provide fast, automatic shut-off when an excessive flow surge is detected in a system, making them ideal for applications involving corrosive, toxic, radioactive or flammable materials, including:

• Compressed air and gas systems
• Pollution control
• Leak detection
• Gas analyzers
• Hydraulic lines
• Sampling station operator protection
• Regulator protection
• Catastrophic failure protection

How it Works

The M-VF valve instantly detects surges in the system’s flow rate. When the surge exceeds a predetermined set point, the valve automatically closes, stopping the fluid flow. Once the line break is repaired and pressure within the system equalizes, the valve will automatically reset, allowing normal flow to resume. 

This automatic reset feature, particularly the intrinsic reset capability (up to 200 psig maximum operating pressure), adds a layer of convenience and system uptime. The valve also features controlled bleed options, and it can operate effectively with both liquids and gasses.  

The M-VF valve’s key features include:

• High reliability: ensures consistent performance in critical safety applications. 
• Field adjustable: users can adjust the shut-off point in the field by turning a screw.  
• Low pressure drop: minimizes impact on system performance during operation.  
• Right-angle flow: provides flexibility in system design and installation.  

Valves are available in various configurations to suit different technical needs:

• Five standard FNPT port sizes: 1/8, 1/4, 3/8, 1/2 and 3/4". 
• The housing, end plug and adjusting screw are available in 316 Stainless Steel or Brass. Magnets in the adjusting screws and pistons are Alnico 5. Other materials like Hastelloy and Monel are also available. 
• Standard O-rings are Viton, with options for Kalrez, Silicone, EPDM, Butyl and Nitrile for optimal chemical compatibility. 
• Maximum operating pressure of 3,000 psig and burst pressure of 5,000 psig (316 SS version).
• Maximum operating temperature of 300° F.

For detailed specifications and ordering information, please visit Malema’s website.