leser safety valve catalogue factory

The primary purpose of a safety valve is to protect life, property and the environment. Safety valves are designed to open and release excess pressure from vessels or equipment and then close again.

The function of safety valves differs depending on the load or main type of the valve. The main types of safety valves are spring-loaded, weight-loaded and controlled safety valves.

Regardless of the type or load, safety valves are set to a specific set pressure at which the medium is discharged in a controlled manner, thus preventing overpressure of the equipment. In dependence of several parameters such as the contained medium, the set pressure is individual for each safety application.

The primary purpose of a pressure relief valve is to protect life, property and the environment. Pressure relief valves are designed to open and release excess pressure from vessels or equipment and then close again.

The function of pressure relief valves differs depending on the main type or loading principle of the valve. The main types of pressure relief valves are spring-loaded, weight-loaded and controlled pressure relief valves.

Regardless of the type or load, pressure relief valves are set to a specific set pressure at which the medium is discharged in a controlled manner, thus preventing overpressure of the equipment. In dependence of several parameters such as the contained medium, the set pressure is individual for each safety application.

Safety valves from the API product group meet all the requirements of API 526 such as standardized capacity, nominal diameter, and center to face dimensions which offers 100% compatibility. Because of their robust construction, they are especially suitable for being constructed from special materials such as Duplex, Monel, and Hastelloy.

API 526 is a purchase specification in which the nominal diameters, flange pressure ratings, center to face dimensions, flow areas, body and spring materials and their service limits are stipulated for "API safety valves" API safety valves are used worldwide in the petrochemical industry, both on- and off-shore. These applications are characterised by standardised plants, blow-down systems and long pipework sections. The LESER type 526 combines the requirements of the API standards and the ASME Code with the tried and tested service reliability of the LESER range.

Safety valves from the Clean Service product group were specially developed for the food, beverage, and pharmaceutical industries and meet all the relevant standards and regulations such as DIN 11866 or ASME BPE. With a low deadspace inlet area, the unique LESER HyTight assembly, and the optional pneumatic lifting device you have very good cleanability (CIP, SIP). With a large selection of aseptic connections (threaded, flanged, or clamped) the valve can be optimally fitted to different requirements.

The safety valves of the 48x series can be fitted with manually lockable lifting devices H4 to hold open at a small lift, and with pneumatic lifting devices H8 for automated systems (CIP process).

Safety valves from the High Performance product group offer especially high capacity for their size. With a large quantity of nominal diameters (DN), pressure ranges and product options, they have proven themselves as a universal safety valve for many applications.

Full Flanged Safety Valves with Flanged Connections open rapidly to the full design lift.They are used in particular for vapours and gases, in applications where the maximum mass flow has to be discharged rapidly. LESER type 441 is suitable for almost any industrial application, and are worldwide one of the best selling spring-loaded flange type safety valves.

Type 441 ANSI: Cast steel construction with ANSI flanges. Two body materials: stainless steel and cast steel. Center to face length in accordance with API 526, greater discharge capacity than standard API valves.

PTFE-lined safety valves from the Critical Service product group are utilized for highly corrosive media such as chlorine, acids, and lyes. With their highly resistant lining they offer a safe solution for corrosive media.

The product group Compact Performance includes threaded and flanged safety valves with compact dimensions for economical protection of small and midsized capacites. Due to its many orifice diameters, seals, and connections this product group offers a very wide area of application.

Type 437:Safety relief valve spring loaded for small mass flows (e.g. thermal expansion and overflow). Body material: stainless steel, 430 chrome steel.

Type 459/462Full lift safety valve spring loaded for the medium mass flow range (e.g. small scale or pilot plant). Two body materials: stainless steel or steel.

Change-over valves from the Best Availability product group increase plant availability.Change-over Valves are used when a plant shutdown is impossible or undesirable for process engineering or commercial reasons. With change-over valves, it is possible to switch over between parallel safety valves without interrupting operation, so as, for example, to perform maintenance work. The design of the change-over valves ensures: low pressure losses on discharge flow (3% criterion) adequate open passage in any position during the change-over process stable operation of the downstream safety valves The combination of LESER change-over and safety valves has been comprehensively tested on full flow test labs.

Safety valves from the Modulate Action product group feature a standard or proportional opening characteristic. They minimize medium loss when opening and are used for protection from pressure peaks, thermal relief, and liquids.

Relief and Safety Relief Valves with Flanged Connections are ideal relief valves for medium mass flows. Their large proportional range leads to consistent functioning and relief of pressure peaks, particularly with liquids. Both proportional and safety relief valves are characterized by particularly stable operation.

LESER Safety Valves for every industrial application Product Range Compact Performance High Performance API Clean Service H2SO4 HNO3 NH3 HCL Critical Service Modulate Action Best Availability High Efficiency Series 810 – Pop Action Type 811 Series 820 – Modulate Action Type 821

Product Range TYPE 811 TYPE 821 LESER Type 811 Pop Action pilot-operated safety valves are non-flowing, which minimizes the flow of media through the pilot for decreased emissions and extended valve life. Set pressure is not affected by back pressure. Features: • Set pressures: 36 – 1480 psig, 2.5 – 63 barg • Sizes: 1" x 2" up to 8" x 10" (DN 25 – DN 200) with API Standard Orifices and Extra (full-bore) Orifices • Adjustable blowdown of 3 – 7% • Complete stainless steel construction of pilot valve • Certified for air / gas service (ASME Section VIII, DIN EN ISO 4126, AD 2000-Merkblatt) Soft...

How to Find the Right Product Group Valve Finder No No No No No No Critical Service Clean Service Best Availability Mediumcontrolled Changeover valve Bursting disc Spring loaded Safety Valves High operating to set pressure ratio, high backpressure or low total height? Clean Service application? Critical Service / highly corrosive application? API specified application? Additional components beyond safety valves Steam, gas and liquid application with low capacity in relation to valve size? High Performance API Compact Performance Modulate Action High Efficiency Orifice F Yes Yes Yes Yes Yes...

LWN 487.71-E 00/02 Contents Chapter/Page General Valve Finder 00/01 Chapter/Page Sizing & Selection How to Construct the Article Number 02/01 How to Construct the Remaining Order Code 02/02 Reference: Identifying the Flange Pressure Rating (ASME) 02/03 Reference: Identifying the Article Number, Series 810 02/05 Reference: Identifying the Article Number, Series 820 02/07 Reference: Application range Soft seal disc / Metal disc 02/09 Reference: • Option Codes for Connections acc. to DIN EN 1092 • Option Codes for Connections acc. to JIS B2220 02/11 02/12 Reference: Option Codes for Flange...

01/01 LWN 487.71-E Series 810 and 820 Overview LESER Pilot Operated Safety Valve (POSV) LESER Pilot Operated Safety Valves (POSVs) are designed according to the API 526 standard. The full range of sizes from 1" x 2" up to 8" x 10" (DN 25 – DN 200) with all orifices from D – T is available for pressure ratings up to pressure class 600 x 150. Beyond API 526, LESER offers so-called Extra Orifices (also known als Full Port or Full Bore nozzles, see page 01/09). The Extra Orifices provide maximum capacity in relation to valve size. In addition, LESER POSVs come in two different functional...

Product Description Series 810 and 820 Specifications and Approvals The LESER Pilot Operated Safety Valve (POSV) comprises the POSV main valve and a pilot valve based on either the Pop Action (Series 810) or the Modulate Action (Series 820) designs. The table below shows their common and their specific features. Specification at a glance Product Description 1) The possible flange pressure ratings depend on the size of the valve. Refer to page 02/11 to verify the correct option codes and availability of DIN EN and JIS flange ratings. LESER Pilot Operated Safety Valve (Main Valve and Pilot...

01/03 LWN 487.71-E Product Description Good Reasons for the LESER Pilot Operated Safety Valve Pilot operated safety valves have been a proven technology for many decades especially in ASME oriented regions. However, some of the older designs show potential for improvement in areas like external tubing, capacity and delivery times. Based on customer feed back and extended research and using Computational Fluid Dynamics (CFD), Rapid Prototyping and one of the most modern factories for safety valves, LESER has developed the latest POSV on the market. The new LESER POSV offers unique benefits...

LWN 487.71-E 01/04 Product Description Feature Benefit for user Benefit for assembler / maintenance High capacity / small size EXTRA ORIFICE Higher capacity for same valve size with Extra Orifice types. For details see page 01/09 Smaller valve sizes possible Small footprint in system -20% Others LESER POSV 20% less space requirement than typical competitive designs Space-saving system designs possible Small footprint in system Modular system Pop Action and Modulate Action pilot valves can be exchanged without tubing modification Easy later upgrade Less spare parts stock required. Easy...

Applications – Functional Areas Across applications, there are four main functional requirements covered by the LESER Pilot Operated Safety Valve (POSV). High Back Pressure Applications • LESER POSVs can be operated in applications with a back pressure ratio (i.e. a ratio of back pressure / set pressure) of up to 70%. Spring loaded safety valves can be typically used up to 50% of back pressure. • The absolute maximum back pressure is determined by the pressure class of the main valve outlet. Typically, LESER POSVs can be used for much higher back pressures than spring loaded safety valves....

Product Description LWN 487.71-E 01/06 Applications – Examples Compressors in Gas Main Systems Pressure relief devices in these applications must allow for high operating pressures in relation to set pressure, which are required for efficient gas transport. Additionally, compressor vibrations put through requirements on the tightness of the safety valve. LESER Series 810 and 820 POSVs offer an ideal solution for these conditions because: • they enable highest possible operating pressure to set pressure ratios facilitating maximum energy density of transport medium • they are not susceptible...

Product Description 01/07 LWN 487.71-E Sour Gas Applications (NACE) LESER Pilot Operated Safety Valves (POSVs) are available for sour gas (H2S) service. Regulatory Requirements The material requirements for hydrogen sulfide (H2S) service (sour gas service) are specified in the NACE standards, MR0175/ISO 15156 (Upstream processes), and MR0103 (Downstream processes). Since the body of the pilot valve is manufactured from stainless steel, only the spring in the pilot valve of the Series 810 Pop Action POSV and the dome spring in the main valve need to be replaced for compliance with these NACE...