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The unique PROTEGO® valve technology minimizes product losses and reduces emissions. For isolated cases and dedicated applications, PROTEGO® offers a range of different Pressure and Vacuum Relief Valves. You can find a product overview on this page below.

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The right device for all application

Valves are subdivided into different types according to being flame transmission proof or non-flame transmission proof and by type of installation. Our range of products covers the following:

Special Features and advantages of PROTEGO® Valves

  • High flow capacity
  • PROTEGO® Valves open later and close earlier ensuring optimized pressure management and saving of inert gases
  • Reduction of product losses
  • Improved tightness


Read more on "Safe Protection of Storage Tanks with Pressure / Vacuum Valves and Flame Arresters"

Valve Technology

Closed vessels or tanks filled with liquids must have an opening through which the accumulated pressure can be released and vacuum in the tank or vessel compensated. For that purpose PROTEGO® Overpressure and Vacuum Relief Valves are provided with weight-loaded or spring-loaded valve discs. In the case of overpressure in the tank, the overpressure valve disc guided in the housing is lifted and releases the volume flow into the atmosphere. When there is a vacuum in the tank, the overpressure of the atmosphere lifts the vacuum disc and the tank is vented.

Operation of the valve under pressure in the tank

Operation of the valve under vacuum in the tank

Pressure and Vacuum Relief Valve

PROTEGO® pressure and vacuum relief valves with full-lift pallet discharge the flow within 10% overpressure from the set pressure to a fully opened valve (full-lift).

Unless otherwise agreed, all PROTEGO® Valves are designed to our 10% technology.

Advantages of the PROTEGO® 10% technology:

  • Maintenance of pressure up to just below the maximum permissible (tank) pressure
  • Minimization of product losses
  • Reduction of emissions


More about PROTEGO® Valve Pallets

PROTEGO® 10% Technology

Discharge with full-lift pallet - CLOSED

Discharge with full-lift

Opening characteristics of valves with different overpressure levels

PROTEGO® Pilot Operated Relief Valves discharge the volume flow without requiring pressure increase. Pilot valves are generally used wherever the valve must be very tightly sealed up to the set pressure. The pilot valves are produced according to API 2000 and have an optimized volume flow.


Advantages of PROTEGO® VN-A-PC, Pressure/Vacuum Pilot-Operated Relief Valve

  • Materials: Stainless steel and low temperature carbon steel
  • Size: DN 4”/4” to DN 12”/16”
  • Temperature range: -200°C to +60°C
  • Set pressure range: +20 to +1034 mbar
  • Set vacuum range: -2,2 to -7 mbar
  • Conformity per API 2000 7th Ed. and ISO 28300
  • Cryogenic Functional Test (per ISO 21013-4)
  • Blow down < 7%
  • Extremely tight valve seat to valve pallet seal

PROTEGO® Emergency Pressure Relief Valves must be used when extremely high venting rates are required due to fire on the outer surface.


PROTEGO® Diaphragm Valves are used at weather-related low temperatures and in sticky, polymerizing media because of their flexible diaphragms. They are the only valves worldwide which are frost-proof down to temperatures of -40°C.


Video "PROTEGO® UB/SF Deflagration- and Endurance burning-proof": watch video 

Video"PROTEGO® UB/SF Frost-Proof Pressure and Vacuum Diaphragm Valve": watch video

Benefits of PROTEGO® Diaphragm Valves

  • high performance seal reducing product loss below EPA’s 500ppm rule preventing environmental pollution
  • set pressure close to opening pressure enables optimum pressure maintenance in the system
  • liquid column height is monitored by level indicators 
  • freeze protection at sub-zero conditions
  • hinged design – maintenance friendly
  • self draining function for condensate
  • particularly suitable for problematic products such as monomers, polymerizing media and vapours with a tendency to condensate, etc.

Special Valves Solutions

Alcohol Applications

PROTEGO® Valves with integrated Flame Arrester

Styrene Application

PROTEGO® UB/SF - Diaphragm Valve with integrated Flame Arrester

Acrylate Applications

PROTEGO® UB/SF - Diaphragm Valve with integrated Flame Arrester

Interested in Valves?

Contact our specialists for your individual requirements.

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