LESER in Panama: safety relief valves for steam, gas and liquids
German safety relief valves — overpressure specialists since 1818
LESER (Hamburg, Germany — founded in 1818) is a safety relief valve manufacturer with more than two centuries of history, specialized in overpressure protection. Its portfolio covers every industrial application: steam, gas, liquids, two-phase fluids, cryogenics, sanitary processes and high pressures, with ASME Section I & VIII certification (V / UV stamps), PED 2014/68/EU (CE), TÜV, API 526, ATEX and TA-Luft. The High Performance family (Type 441) is its main line; the API, Compact, Clean, Critical, Pilot Operated and Change-Over series cover the other process requirements. Beiton provides sizing to ASME/API, technical selection by fluid and condition (steam, gas, liquid, two-phase), direct import, certified test bench work and genuine spare parts.
Product lines we represent
We work with the complete LESER portfolio. If you need a piece of equipment or a line that isn't listed, get in touch — we source that too.
High Performance — Global standard
- Type 441 — Flanged PRV, the world's best seller (steam, gas and liquid)
- Type 437 — Compact threaded PRV for fast installation
- Type 458/459 — Reinforced construction for critical service
- Type 4412 — Jacketed version for viscous fluids
API Series — Petrochemicals and refineries
- Type 526 — Flanged API 526 valve, DN25–DN200
- API materials: WCC, LCC, WC6, CF8M, duplex
- Conventional, bellows-balanced and pilot-operated
- Built to API 520/521/526/527
Compact Performance — OEM, skids and panels
- Type 481/483 — Compact threaded PRV for air, gas and liquids
- Type 485/487 — Compact flanged versions
- Design optimized for tight spaces and OEM series
Clean Service — Pharmaceuticals, food and beverage
- Type 481/483 CLEAN — Sanitary stainless steel, internal finish down to Ra 0.375 μm
- Tri-clamp / ASME BPE connections
- Compliant with FDA, EHEDG and 3-A Sanitary
- CIP/SIP designs with full traceability
Critical & Pilot Operated — Demanding processes
- Type 459 — Cryogenic service (LNG, LPG, liquid N₂/O₂)
- POSV Type 810/811 — Pilot-operated up to 420 bar
- Operation up to 98 % of set pressure
- Modulating-action valves for reactors and compressors
Special systems and accessories
- Change-Over Valves Type 320/330 — Redundant PRVs with no process shutdown
- Supplementary Loading System (SLS) — Operation up to 95 % of Pset
- Rupture discs and combined disc + PRV assemblies
- Silencers, relief headers and block valves
They make one thing only: safety relief valves
LESER doesn't make pumps, doesn't make control valves, doesn't make actuators: it is devoted entirely to safety relief valves. That focus shows in the Type 441, its benchmark safety relief valve, and in a modular concept that makes it possible to deliver specific configurations in weeks instead of months.
VALVESTAR® — Free online sizing
LESER makes VALVESTAR® available, its online safety relief valve sizing software used by project engineers worldwide. It calculates the required orifice, checks back pressure and generates a technical calculation report compliant with ISO 4126, API 520/521/526 and ASME VIII. At Beiton we use it on every quote to deliver traceable sizing and a ready datasheet.
Open VALVESTAR®Global certifications
Every LESER valve arrives with full traceability and certification to the global codes your plant or end client requires.
Best-selling LESER equipment
Type 441 — High Performance
The world's best-selling safety relief valve. Flanged ASME/PED PRV for steam, gas and liquids, with a certified discharge coefficient and broad D–T orifice coverage.
Type 526 — API 526
Flanged API 526 safety relief valve for refineries and petrochemicals. Available in WCC, LCC, WC6 and CF8M, conventional or bellows-balanced for variable back pressure.
Type 459 — Critical Service
PRV for critical and cryogenic service: LNG, LPG, liquid nitrogen and oxygen. Reinforced construction with a thermal extension and seals rated for low temperatures.
Type 483 Clean Service
Sanitary 316L stainless safety relief valve with an internal finish down to Ra 0.375 μm and clamp connections. Designed for pharmaceuticals, food and beverage, CIP/SIP compatible.
POSV Type 810 — Pilot Operated
Pilot-operated valve up to 420 bar that allows operation up to 98 % of the set pressure without leakage. Ideal for processes that run close to set point with no leakage.
Type 320 — Change-Over
Manual three-way changeover for redundant systems with two PRVs. Lets you service one valve without stopping the process, per PED and ASME inspection.
Type 437 — Threaded HP
Threaded version of the High Performance family for fast installation on small boilers, pressure vessels and utility lines. NPT/BSP, bronze or stainless steel.
Supplementary Loading System
Supplementary loading system that lets the process run at up to 95 % of the set pressure with no leakage. Ideal where operating margin is critical.
Where we apply LESER
Need technical advice on LESER?
Our engineering team knows the LESER portfolio in depth. We help you select the right equipment, size it for your application and carry out commissioning.