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Pressure Relief Valve

  • 10% technology for minimum pressure increase up to full lift
  • extreme tightness, resulting in lowest possible product losses and reduced environmental pollution
  • set pressure close to opening pressure for optimum pressure maintenance in the system
  • particularly high flow capacity
  • valve pallet is guided inside the housing to protect against harsh weather conditions
  • can be used in explosion hazardous areas
  • best technology for API tanks

Function and Description

The D/SVL type PROTEGO® valve is a high performance pressure relief valve. It is primarily used as a device for relieving pressure in tanks, containers, and process engineering equipment. The valve offers reliable protection against overpressure and prevents excessive loss of product vapors close to the set pressure.

The device will start to open as soon as the set pressure is reached and only requires 10% overpressure to full lift. Continuous investments in and a commitment to research and development have allowed PROTEGO® to develop a low pressure valve which has the same opening characteristic as a high pressure safety relief valve.

With this “full lift type” technology, the valve can be set at just 10% below the maximum allowable working pressure of the tank and still safely vent the required mass flow.

Due to the highly developed manufacturing technology, the tank pressure is maintained up to the set pressure with a tightness that is far superior to the conventional standard. This feature is achieved by valve seats made of high quality stainless steel and with precisely lapped valve pallets (1), or with an air cushion seal (2) in conjunction with high quality FEP diaphragm. The valve pallets are also available with a PTFE seal to prevent the valve pallet from sticking when sticky products are used, and they enable the use of corrosive substances. After the overpressure is released, the valve re-seats and provides a tight seal again.

The optimized fluid dynamic design of the valve body and valve pallet is a result of many years of research, resulting in a stable operation of the valve pallet, optimized performance, and reduced product losses.


To select the nominal size (DN), use the flow capacity chart on the following page

DN50 / 2" 80 / 3"100 / 4"150 / 6"200 / 8" 250 / 10"300 / 12
a336 / 13.23412 / 16.22444 / 17.48564 / 22.20664 / 26.20687 / 27.05687 / 27.05
b200 / 7.87295 / 11.61295 / 11.61465 / 18.31550 / 21.65650 / 25.59650 / 25.59
Dimensions in mm / inches

Material selection for housing

Design AB
HousingSteelStainless Steel
Valve seatStainless SteelStainless Steel
Weather hoodStainless SteelStainless Steel
Special materials upon request

Material selection for pressure valve pallet

Design  ABCDEF
Pressure range [mbar]
[inch W.C.]
+2,0 up to +3,5
+0.8 up to +1.4
>+3,5 up to +14
>+1.4 up to +5.6
>+14 up to +35
>+5.6 up to +14
>+35 up to +60
>+14 up to +24
>+14 up to +35
>+5.6 up to +14
>+35 up to +60
>+14 up to +24
Valve palletAluminiumStainless SteelStainless SteelStainless SteelStainless SteelStainless Steel
SealingFEPFEPMetal to MetalMetal to MetalPTFEPTFE
Special materials and devices with higher set pressure or vacuum are available upon request

Flange connection type

EN 1092-1; Form B1
ASME B16.5 CL 150 R.F.
other types upon request

Design Types and Specifications

The valve pallet is weight-loaded. Higher pressures can be achieved upon request with a special spring-loaded design.

Pressure valve in basic design


Additional special devices available upon request.


Pressure: +2.0 mbar +60 mbar
+2.0 inch W.C. +24 inch W.C.
Higher pressure settings upon request.

Flow Capacity Chart

The flow capacity charts have been determined with a calibrated and TÜV certified flow capacity test rig. Volume flow V in (m³/h) and CFH refer to the standard reference conditions of air ISO 6358 (20°C, 1bar). For conversion to other densities and temperatures refer to Sec. 1: “Technical Fundamentals”.