Leser Valves


LESER ranks among the pioneers of mechanical engineering in Germany. The company started in Germany in 1818 as a brass foundry and developed a product portfolio of components of mechanical equipment and machines during the “industrial revolution”.

In 1885 the company developed its first safety valve for the protection of steam boilers. Even at that early date, LESER products were working for the safety of man and the environment. Since the 1970′s LESER has specialized only in safety valves.

As industrial development has progressed, the demands for safety have continuously increased. Step by step, LESER has developed its safety valves to reflect the state of the art and extended its product range to provide solutions for all sectors of industry. Investment in research and development is therefore an important impetus for new developments at LESER and in the industry as a whole. LESER sets standards – now and in the future.

Headquartered in Germany, with a state of the art factory and more than 500 employees worldwide LESER is supplying high quality safety valves over the world. Today, LESER’ s product range comprises a total of 7 product groups with 38 valve types. A variety of materials and sizes from DN 10 to DN 400 – 1/2″ to 16″, provide safe solutions for almost every industrial application. Annual production currently amounts to 90,000 safety valves.

High Performance

 Type 441, 442 DIN DN 20 – 200
  Type 441, 442 ANSI NPS 1″ – 4″
  Type 441, 442 XXL DN 200 – 400
  Type 441, 442 Full nozzle DIN DN 25 – 50
  Type 441, 442 Full nozzle ANSI NPS 1” – 4”
  Type 444 DIN DN 25 – 80
  Type 444 ANSI NPS 1” – 3”
  Type 455, 456 DN 25 – 100, NPS 1″ – 4″
  Type 457, 458 DN 25 – 150, NPS 1″ – 6″

API Series

 Type 526 NPS 1″ – 8″, Orifice D – T

High Efficiency

 Series 810 – Pop Action NPS 1″ – 8″, Orifice D – T
  Series 820 – Modulate Action NPS 1″ – 8″, Orifice D – T

Compact Performance

 Type 437 do 6 – 10 mm
  Type 438 do 10 mm
  Type 439 do 10 mm
  Type 459 do 9 – 17,5 mm
  Type 459 HDD do 6 – 13 mm
  Type 462 do 9 – 17,5 mm
  Type 462 HDD do 9- 13 mm

Clean Service

 Type 481 do 10
  Type 483 do 13 – 25mm
  Type 484 do 13 – 25mm
  Type 485 do 13 – 25mm
  Type 488 do 23 – 92mm

Critical Service

 Type 546 DN 25 – 100
  Type 5466 DN 25 – 50
  Type 447 DN 25 – 100, NPS 1″ – 4″
  Type 449 DN 25 – 100, NPS 1″ – 4″

Modulate Action

 Type 427, 429 DN 15 – 150
  Type 431, 433 DN 15 – 150
  Type 431, 433 PN 160, DN 15