High Perfomance - Universal safety valves | LESER
High Performance
High Performance Safety Valve from LESER

Safety valves for all industrial applications

  • High capacities in comparison to nominal size
  • Wide range of nominal sizes
  • Wide range of options available
  • Excellent price-performance ratio
  • LESER Nanotightness: Exceeds the tightness requirements of API 527 by 50%


LESER High Performance safety valves are designed, marked, produced and approved according to the requirements of the following regulations:

  • LESER CE Approvel
  • LESER ASME Approvel
  • LESER EAC Approvel
  • LESER Chinese TS Approvel

Valve Types

Type 441, 442 DIN

DIN Flange

DN 20 - DN 200 (3/4" - 8")

Type 441, 442 ANSI

ANSI Flange

DN 25 - DN 100 (1" - 4")

Type 441, 442

High nominal diameter

DN 250 - DN 400 (10" -16")

Type 444 DIN

Deep-drawn body

DN 25 - DN 80 (1" - 3")

Type 444 ANSI

Deep-drawn body

DN 25 - DN 80 (1" - 3")

Type 441, 442 Full nozzle DIN


DN 25 - DN 50 (1" - 2") 

Type 441, 442 Full nozzle ANSI


DN 25 - DN 100 (1" - 4") 

Type 455, 456

High pressure with seat

DN 25 - DN 100 (1" - 4") 

Type 457, 458

High pressure with seat

DN 25 - DN 150 (1" - 6") 

Technical data High Perfomance

Nominal Diameter at Inlet
DN 20 - DN 400 | 3/4" - 16"
Actual Orifice Diameter d₀
18 mm - 295 mm | 0.71 in - 11.61 in
Actual Orifice Area A₀
254 mm² - 68349 mm² | 0.394 in² - 105.942 in²
0.1 bar - 300 bar | 1.5 psig - 4,350 psig
Temperature (in accordance with DIN EN)
-270 °C to 550 °C | -454 °F to 1,022 °F
Body Material
0.6025, 0.7043, 1.0619, 1.4408, 1.0460 / 1.0425, 1.4571, 1.4404, 1.4581, 1.7357 | Cast iron, Ductile Gr. 60-40-18, SA 216 WCB, SA 351 CF8M, carbon steel, 316Ti, SA 479 316L, SA 351 CF10M , SA 217 WC6
Valve Connection
Flange in accordance with DIN EN 1092 or ASME B 16.5
Bellows Material (optional)
Stainless steel, elastomer
Load Type
Oil Refinery at Twilight

Case Study

Bottom Up Valves at Aerzen.


OEM for different industries

LESER Solution:

High Performance and API

The challenges
As an internationally operating OEM Aerzener Maschinenfabrik has to fulfil a many local, legal requirements as well as customer specifications, of e.g. pressure equipment. Every region has its own set of rules: For example in Europe applies the pressure equipment directive and in America the ASME Code. In addition to the general requirement for global approval concepts, e.g. for pressure equipment according to PED or ASME, the trend among companies is towards modular systems. Planners are trying to use small, linkable systems in order to be able to work flexible and scalable. This makes it easier to coordinate plant capacities. This modularization considerably limits the installation space and freedom in the design or development of e.g. compressors. 

In addition to the small installation space of the above-mentioned compressors, they should be completely covered by an acoustic enclosure to reduce noise emissions. In order to reduce the size of the very cost-intensive sound enclosure, AERZEN requires special valves that are adapted to the available small installation space. Compressors are discontinuous machines for pressure generation.
In order to ensure that occurring pulsations do not impair the function of the safety valve, the set pressure of the valve is adjusted accordingly and an appropriate distance to the pressure line is ensured by design.

The LESER solution
As a renowned manufacturer of safety valves, it is advantageous to be able to react flexibly to the above-mentioned concerns, primarily to the small installation space, with its portfolio. Being able to change the installation position of safety valves is a clear advantage for the compressor designer. They are much more variable in their design and construction options and can also respond more flexibly to special customer specifications. If the progressive modularization of compressors requires more compact designs, safety valves in different mounting positions, for example, can be an answer to the problem, unlike the classic upright position. In addition, the spindle guide plays a special role here. The friction at the guiding points must be reduced as much as possible so that the spindle runs smoothly. Otherwise, a safety valve can only be installed vertically.

Why LESER safety valves?
For a global acting OEM like AERZEN, a specialist like LESER, who has not only the knowledge but also the necessary approvals, is an important component for success. LESER offers a global approval concept that allows safety valves to be used regardless of location. When ordering safety valves, only the applicable regulations must be specified in order to ensure appropriate labeling and material selection. In addition, LESER has tested and approved further installation positions in addition to the conventional installation situation, standing on the inlet pipeline. For example, some types of valves may be installed with a horizontal stem or even upside down, e.g. Types 526 and 441. For horizontal installation, care must be taken to align the outlet. Liquids, e.g. in the form of condensate, should be able to drain off downwards to avoid back pressures and even corrosion. When installed upside down, the inverted weight forces are corrected by correction factors. LESER offers not only safety valves with basic documentation and accessories but also other special documentation and options. From the “Fugitive Emission Test” with helium up to 3.2 ship class castings and from back pressures up to more than 200 bar-g to high pressure heating jackets for up to 30 bar-g, LESER sales engineers develop solutions for customer specific applications as described above for AERZEN.

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