Safety / Pressure Relief Valves

LESER Safety Valve

LESER Safety Valves are developed and manufactured for the international market in Germany. With a capacity of over 130,000 valves a year, LESER is the largest manufacturer of safety valves in Europe and a leader in much of the world.

LESER provides a full line of pressure relief valves, as shown below, which is supported by a broad range of authorized repair centers and assemblers worldwide.

Extensive stock of valves is maintained at the LESER US facility in Charlotte, North Carolina to guarantee short delivery times. A full range of spare parts, including springs, discs, nozzles, bellows kits, lifting devices, gaskets etc. are also kept in inventory to handle quick shipment requirements.

LESER is able to supply valves into applications requiring the UV stamp, CE mark, Canadian CRN Certification and other world-wide approvals from stock. LESER US maintains a fully operational assembling and setting facility which is certified by the ASME, National Board.

API 526 Series

Safety valves from the API 526 Series product group meet all the requirements of API 526 such as standardized capacity and nominal diameter through the entire D to T orifice product range as well as standard center to face dimensions which offer 100% compatibility. Product features include:

  • Valve sizes 1" through 8", D through T Orifice
  • Materials: WCB, CF8M, WC6, LCB, special alloys
  • Design according to API 526
  • Great variety of options and flanged connections available
  • Standard metal sealing with optional o-ring disc readily available
  • Single trim for steam, gas and liquid

Compact Performance 437 / 459 Series

Threaded and flanged safety valves with compact dimensions for economical protection of small and midsized capacities. Many orifice diameters, seals and connections offer a very wide area of application. Product features include:

  • Great variety of threaded or flanged connections
  • Valve sizes from 1/2" through 2"
  • Broad set pressure range up to 11600 psig
  • Wide range of materials and options to fit any application
  • Stellited metal sealing for longer product life
  • Soft seat for superior tightness
  • Single trim for steam, gas and liquid

High Performance 441 Series

Flanged safety valves with especially high capacity for their size. With a large quantity of valve sizes, pressure ranges and product options, they have proven themselves as a universal safety valve for many applications. Product features include:

  • Great variety of types, materials and options to fit any application
  • Valve sizes from DN 20 through DN 400, 1" through 16"
  • Flange connections according to DIN EN, ASME and other
  • High capacity compared to the API requirements
  • Standard metal sealing
  • Single trim for steam, gas and liquid

Critical Service 447 Series

PTFE-lined flanged safety valves for corrosive media such as chlorine, acids, and lyes. With their highly resistant lining they offer a safe solution for corrosive media. Product features include:

  • Valve sizes 1" through 4"
  • Flange connections according to ASME
  • Body is resistant against most chemicals by special coating PTFE lining or special metals
  • A PTFE or metal bellows protects the bonnet area against product influences
  • Smooth inside surface avoid adherence of corrosive matters
  • Single trim for gas and liquid

High Efficiency 800 Series

Pop Action and Modulate Action Pilot-operated safety valves for optimal tightness right up to set pressure. Product features include:

  • Valve sizes 1" through 8", D through T orifice
  • Materials: WCB, LCB, CF8M
  • Full bore for higher capacity based on nominal size.
  • Internal tubing means: No leakage, no freezing
  • Backflow preventer as standard reduces cost and eases ordering

Best Availability 310 Series Change-over Valves

Change-over valves are used for increased plant availability in cases where a process or application cannot or should not be switched off. Product features include:

  • Uninterrupted operation
  • Simple handling
  • Heavy-duty design
  • Low pressure loss due to streamlined construction
  • Compact construction for space saving installation

Web Based Downloadable Certificates / Test Reports

The Certificates area gives the customer the opportunity to download and save the ordered certificates for individual safety valves or for an entire order. The only thing that is needed is either the serial and article number of the safety valve, or the customer and LESER job number.

Horizontal Installation / Shipping

LESER confirms that it is possible to install every LESER spring loaded safety valve in a non-upright position if some simple criteria are met.

The following LESER design features enable horizontal installation:

  • One piece spindle
  • Bushing between spindle and adjusting screw
  • Widely spaced top and bottom guiding
  • Reduced guiding surface area
  • Self-draining and flat bottomed body bowl

LESER Valves are shipped horizontally on a pallet, in card board boxes or crates. The design features described above ensure that horizontal shipping is unproblematic. Valves shipped horizontally require less space which in turn leads to less freight charges.

Sizing of Safety Relief Valves

LESER offers the VALVESTAR Safety Relief Sizing Program for use on its own Website (no download necessary). New users: click on the "New User Registration" link to create your own username and password, and begin using the software.

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