leser safety valve data sheet quotation

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.

Project: Gas mixing panel Gas: Oxygen Pressure Safety Valve Size: G3/8” or ½” + Material: Brass or Equivalent suitable oxygen service + Set pressure: 170 bar + Working pressure: 150 bar + Q’ty: 1 Pc - Document request: + Detail drawing with a material component + Certification oxygen cleaned + Certificate type approval for Oxygen

The basis is the especially efficient LESER safety valve High Performance Type 441 for high discharge capacities. Flange facings groove-groove according to DIN EN 1092 make it suitable for refrigeration technology applications. In addition, it provides high functional tightness and reduces emissions.

Leser Safety Valve for Steam, Gases & Liquids, WCB Body/316L seat/hardened MT440SS Disc or 316SS Body/316L seat/disc, flanged ends to either DIN, AS Tables or Ansi 150#RF (or Ansi 300#RF x Ansi 150#RF)

VARIVENT® Safety valves 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.

VARIVENT® Safety valves 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.

Full-life safety valves open pop action so that it is possible to release high mass flow rates or quick occurring pressures. They are often used in steam or gas applications. These valves  open completely even at small pressure rises and can therefore discharge the full mass flow.

Normal stroke safety valves are optimal pressure relief valves. They have got a wide proportional area so that they steadily activate during pressure relief and pressure peaks. Their long proportional phase have nearly full-life character. These similar properties can reduce big mass flows. They are also used as overflow valves and when smaller sizes of full-life safety valves are still to big.

To guarantee that all product touched surfaces can be cleaned hygienically (CIP) or sterilized (SIP) it is possible to get the valves with optional pneumatic lifting device.

Safety valves prevent tanks against overpressure for example vessels within a sterilization process or during tank filling. They protect fermentation tanks prior damages in case of unexpected disturbance.

Normal stroke safety valves are optimal pressure relief valves. They have got a wide proportional area so that they steadily activate during pressure relief and pressure peaks. Their long proportional phase have nearly full-life character. These similar properties can reduce big mass flows. They are also used as overflow valves and when smaller sizes of full-life safety valves are still to big.

Very good cleanability - this is the requirement  for the design of the LESER Clean Service safety valves. These valves are equipped with the HyTight Assembly which offers optimal cleaning possibilities.

Safety valves of the VARIVENT series have got gas sealed lifting devices of the valve disk. This design makes enables the lifting of the valve disk during pipe cleaning to clean all inner parts including seat area and O-Ring. There are either manual as well as pneumatic lifting devices available.

The Safety Relief Valves series 488 were developed in close cooperation with plant owners and engineers. They reliably protect process plants from overpressure without putting hygienic requirements at risk. The whole series has been designed and officially approved according to international standards (DGR 97/23/CG, ASME, GOST, etc.).

A variant for steam, gas and liquid of each valve has been type-tested by TÜV in accordance with German regulations. They comply with the EU directive for pressure equipment and bear the CE symbol. The VARIVENT(R) Safety Valve Type 488 fulfills the special cleaning and performance abilities which are required for the food, brewery und beverage industry. It has a wide performance area so that is very good applicable for large plants.

A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits. Pilot-operated relief valves are a specialized type of pressure safety valve. A leak tight, lower cost, single emergency use option would be a rupture disk.

Safety valves were first developed for use on steam boilers during the Industrial Revolution. Early boilers operating without them were prone to explosion unless carefully operated.

Vacuum safety valves (or combined pressure/vacuum safety valves) are used to prevent a tank from collapsing while it is being emptied, or when cold rinse water is used after hot CIP (clean-in-place) or SIP (sterilization-in-place) procedures. When sizing a vacuum safety valve, the calculation method is not defined in any norm, particularly in the hot CIP / cold water scenario, but some manufacturers

The earliest and simplest safety valve was used on a 1679 steam digester and utilized a weight to retain the steam pressure (this design is still commonly used on pressure cookers); however, these were easily tampered with or accidentally released. On the Stockton and Darlington Railway, the safety valve tended to go off when the engine hit a bump in the track. A valve less sensitive to sudden accelerations used a spring to contain the steam pressure, but these (based on a Salter spring balance) could still be screwed down to increase the pressure beyond design limits. This dangerous practice was sometimes used to marginally increase the performance of a steam engine. In 1856, John Ramsbottom invented a tamper-proof spring safety valve that became universal on railways. The Ramsbottom valve consisted of two plug-type valves connected to each other by a spring-laden pivoting arm, with one valve element on either side of the pivot. Any adjustment made to one of valves in an attempt to increase its operating pressure would cause the other valve to be lifted off its seat, regardless of how the adjustment was attempted. The pivot point on the arm was not symmetrically between the valves, so any tightening of the spring would cause one of the valves to lift. Only by removing and disassembling the entire valve assembly could its operating pressure be adjusted, making impromptu "tying down" of the valve by locomotive crews in search of more power impossible. The pivoting arm was commonly extended into a handle shape and fed back into the locomotive cab, allowing crews to "rock" both valves off their seats to confirm they were set and operating correctly.

Safety valves also evolved to protect equipment such as pressure vessels (fired or not) and heat exchangers. The term safety valve should be limited to compressible fluid applications (gas, vapour, or steam).

For liquid-packed vessels, thermal relief valves are generally characterized by the relatively small size of the valve necessary to provide protection from excess pressure caused by thermal expansion. In this case a small valve is adequate because most liquids are nearly incompressible, and so a relatively small amount of fluid discharged through the relief valve will produce a substantial reduction in pressure.

Flow protection is characterized by safety valves that are considerably larger than those mounted for thermal protection. They are generally sized for use in situations where significant quantities of gas or high volumes of liquid must be quickly discharged in order to protect the integrity of the vessel or pipeline. This protection can alternatively be achieved by installing a high integrity pressure protection system (HIPPS).

In the petroleum refining, petrochemical, chemical manufacturing, natural gas processing, power generation, food, drinks, cosmetics and pharmaceuticals industries, the term safety valve is associated with the terms pressure relief valve (PRV), pressure safety valve (PSV) and relief valve.

The generic term is Pressure relief valve (PRV) or pressure safety valve (PSV). PRVs and PSVs are not the same thing, despite what many people think; the difference is that PSVs have a manual lever to open the valve in case of emergency.

Relief valve (RV): an automatic system that is actuated by the static pressure in a liquid-filled vessel. It specifically opens proportionally with increasing pressure

Pilot-operated safety relief valve (POSRV): an automatic system that relieves on remote command from a pilot, to which the static pressure (from equipment to protect) is connected

Low pressure safety valve (LPSV): an automatic system that relieves static pressure on a gas. Used when the difference between the vessel pressure and the ambient atmospheric pressure is small.

Vacuum pressure safety valve (VPSV): an automatic system that relieves static pressure on a gas. Used when the pressure difference between the vessel pressure and the ambient pressure is small, negative and near to atmospheric pressure.

Low and vacuum pressure safety valve (LVPSV): an automatic system that relieves static pressure on a gas. Used when the pressure difference is small, negative or positive and near to atmospheric pressure.

In most countries, industries are legally required to protect pressure vessels and other equipment by using relief valves. Also, in most countries, equipment design codes such as those provided by the ASME, API and other organizations like ISO (ISO 4126) must be complied with. These codes include design standards for relief valves and schedules for periodic inspection and testing after valves have been removed by the company engineer.

Today, the food, drinks, cosmetics, pharmaceuticals and fine chemicals industries call for hygienic safety valves, fully drainable and Cleanable-In-Place. Most are made of stainless steel; the hygienic norms are mainly 3A in the USA and EHEDG in Europe.

The first safety valve was invented by Denis Papin for his steam digester, an early pressure cooker rather than an engine.steelyard" lever a smaller weight was required, also the pressure could easily be regulated by sliding the same weight back and forth along the lever arm. Papin retained the same design for his 1707 steam pump.Greenwich in 1803, one of Trevithick"s high-pressure stationary engines exploded when the boy trained to operate the engine left it to catch eels in the river, without first releasing the safety valve from its working load.

Although the lever safety valve was convenient, it was too sensitive to the motion of a steam locomotive. Early steam locomotives therefore used a simpler arrangement of weights stacked directly upon the valve. This required a smaller valve area, so as to keep the weight manageable, which sometimes proved inadequate to vent the pressure of an unattended boiler, leading to explosions. An even greater hazard was the ease with which such a valve could be tied down, so as to increase the pressure and thus power of the engine, at further risk of explosion.

Although deadweight safety valves had a short lifetime on steam locomotives, they remained in use on stationary boilers for as long as steam power remained.

Weighted valves were sensitive to bouncing from the rough riding of early locomotives. One solution was to use a lightweight spring rather than a weight. This was the invention of Timothy Hackworth on his leaf springs.

These direct-acting spring valves could be adjusted by tightening the nuts retaining the spring. To avoid tampering, they were often shrouded in tall brass casings which also vented the steam away from the locomotive crew.

The Salter coil spring spring balance for weighing, was first made in Britain by around 1770.spring steels to make a powerful but compact spring in one piece. Once again by using the lever mechanism, such a spring balance could be applied to the considerable force of a boiler safety valve.

The spring balance valve also acted as a pressure gauge. This was useful as previous pressure gauges were unwieldy mercury manometers and the Bourdon gauge had yet to be invented.

Paired valves were often adjusted to slightly different pressures too, a small valve as a control measure and the lockable valve made larger and permanently set to a higher pressure, as a safeguard.Sinclair for the Eastern Counties Railway in 1859, had the valve spring with pressure scale behind the dome, facing the cab, and the locked valve ahead of the dome, out of reach of interference.

In 1855, John Ramsbottom, later locomotive superintendent of the LNWR, described a new form of safety valve intended to improve reliability and especially to be tamper-resistant. A pair of plug valves were used, held down by a common spring-loaded lever between them with a single central spring. This lever was characteristically extended rearwards, often reaching into the cab on early locomotives. Rather than discouraging the use of the spring lever by the fireman, Ramsbottom"s valve encouraged this. Rocking the lever freed up the valves alternately and checked that neither was sticking in its seat.

A drawback to the Ramsbottom type was its complexity. Poor maintenance or mis-assembly of the linkage between the spring and the valves could lead to a valve that no longer opened correctly under pressure. The valves could be held against their seats and fail to open or, even worse, to allow the valve to open but insufficiently to vent steam at an adequate rate and so not being an obvious and noticeable fault.Rhymney Railway, even though the boiler was almost new, at only eight months old.

Naylor valves were introduced around 1866. A bellcrank arrangement reduced the strain (percentage extension) of the spring, thus maintaining a more constant force.L&Y & NER.

All of the preceding safety valve designs opened gradually and had a tendency to leak a "feather" of steam as they approached "blowing-off", even though this was below the pressure. When they opened they also did so partially at first and didn"t vent steam quickly until the boiler was well over pressure.

The quick-opening "pop" valve was a solution to this. Their construction was simple: the existing circular plug valve was changed to an inverted "top hat" shape, with an enlarged upper diameter. They fitted into a stepped seat of two matching diameters. When closed, the steam pressure acted only on the crown of the top hat, and was balanced by the spring force. Once the valve opened a little, steam could pass the lower seat and began to act on the larger brim. This greater area overwhelmed the spring force and the valve flew completely open with a "pop". Escaping steam on this larger diameter also held the valve open until pressure had dropped below that at which it originally opened, providing hysteresis.

These valves coincided with a change in firing behaviour. Rather than demonstrating their virility by always showing a feather at the valve, firemen now tried to avoid noisy blowing off, especially around stations or under the large roof of a major station. This was mostly at the behest of stationmasters, but firemen also realised that any blowing off through a pop valve wasted several pounds of boiler pressure; estimated at 20 psi lost and 16 lbs or more of shovelled coal.

Pop valves derived from Adams"s patent design of 1873, with an extended lip. R. L. Ross"s valves were patented in 1902 and 1904. They were more popular in America at first, but widespread from the 1920s on.

Although showy polished brass covers over safety valves had been a feature of steam locomotives since Stephenson"s day, the only railway to maintain this tradition into the era of pop valves was the GWR, with their distinctive tapered brass safety valve bonnets and copper-capped chimneys.

Developments in high-pressure water-tube boilers for marine use placed more demands on safety valves. Valves of greater capacity were required, to vent safely the high steam-generating capacity of these large boilers.Naylor valve) became more critical.distilled feedwater and also a scouring of the valve seats, leading to wear.

High-lift safety valves are direct-loaded spring types, although the spring does not bear directly on the valve, but on a guide-rod valve stem. The valve is beneath the base of the stem, the spring rests on a flange some height above this. The increased space between the valve itself and the spring seat allows the valve to lift higher, further clear of the seat. This gives a steam flow through the valve equivalent to a valve one and a half or twice as large (depending on detail design).

The Cockburn Improved High Lift design has similar features to the Ross pop type. The exhaust steam is partially trapped on its way out and acts on the base of the spring seat, increasing the lift force on the valve and holding the valve further open.

To optimise the flow through a given diameter of valve, the full-bore design is used. This has a servo action, where steam through a narrow control passage is allowed through if it passes a small control valve. This steam is then not exhausted, but is passed to a piston that is used to open the main valve.

There are safety valves known as PSV"s and can be connected to pressure gauges (usually with a 1/2" BSP fitting). These allow a resistance of pressure to be applied to limit the pressure forced on the gauge tube, resulting in prevention of over pressurisation. the matter that has been injected into the gauge, if over pressurised, will be diverted through a pipe in the safety valve, and shall be driven away from the gauge.

There is a wide range of safety valves having many different applications and performance criteria in different areas. In addition, national standards are set for many kinds of safety valves.

Safety valves are required on water heaters, where they prevent disaster in certain configurations in the event that a thermostat should fail. Such a valve is sometimes referred to as a "T&P valve" (Temperature and Pressure valve). There are still occasional, spectacular failures of older water heaters that lack this equipment. Houses can be leveled by the force of the blast.

Pressure cookers usually have two safety valves to prevent explosions. On older designs, one is a nozzle upon which a weight sits. The other is a sealed rubber grommet which is ejected in a controlled explosion if the first valve gets blocked. On newer generation pressure cookers, if the steam vent gets blocked, a safety spring will eject excess pressure and if that fails, the gasket will expand and release excess pressure downwards between the lid and the pan. Also, newer generation pressure cookers have a safety interlock which locks the lid when internal pressure exceeds atmospheric pressure, to prevent accidents from a sudden release of very hot steam, food and liquid, which would happen if the lid were to be removed when the pan is still slightly pressurised inside (however, the lid will be very hard or impossible to open when the pot is still pressurised).

VALVESTAR is a unique software used to size and calculate a LESER safety valve. It operates according to worldwide leading codes and standards, such as API, ASME VIII or AD 2000-Merkblatt, while considering the entire product range of LESER.

The customer is lead step-by-step throughout the sizing-process which makes sizing and measuring easy and most importantly more safe. VALVESTAR is available in more than 15...

... have been type tested as well. These pressure regulators have safety valves which will slam shut in the event of emergencies, such as the gas reaching too high a pressure level. The valve ...

This product has hydraulically actuated class A gas safety valves to EN 161 used for automatic shut-off. It shuts off when unstimulated for gas and air, or even biologically produced methane. It has AISi ...

The S 104 Safety Shut Off valve is mainly used to avoid any damage to components as well as to avoid too high or too low pressure in the gas train. This could cause high financial losses and/or injured ...

The S100 Safety Shut Off valve is mainly used to avoid any damage to components as well as to avoid too high or too low pressure in the gas train. This could cause high financial losses and/or injured ...

130 Series Safety valves are also available as Relief valves. Relief valves, identified by the letter R after the type number, are devices with an operational function, ...

... potential risks, BHGE’s line of Consolidated safety valves offers extreme dependability in potentially dangerous circumstances. With a range of styles, models, and configurations to choose from, our safety ...

ASME Sections I & VIII air and steam capacity certified safety valve for overpressure protection of steam power boilers, deaerators, accumulators, pressure

Resilient-seated non-return valve as pump protection valve with innovative design and safety function. The spring-assisted disk closes independent of electric actuation. ...

Full-lift angle weight safety valve with flanged ends. The product is characterized by a high degree of tightness. Valves 570 may be applied to systems in ...

Flanged safety and relief valves, standard or full-lift valves; even though as overflow-valves; material steel / nodular iron or complete stainless steel; ...

A Conventional Safety Relief Valve (PRV) uses a spring to keep the valve closed until the process nears the set pressure. The spring force pushes the valve’s disc against ...

Flanged safety valve that meet requirements of ASME Secc. VIII and API 526 available in different material options to fulfill any customer requirement.

Flange Full Lift Safety Valves can be used on systems where the discharge is relatively simple. The pressure in the discharge system can be atmospheric, at a constant level or where the ...

Pilot Type Pressure Relief Valve Market Size is projected to Reach Multimillion USD by 2028, In comparison to 2021, at unexpected CAGR during the forecast Period 2022-2028.

Browse Detailed TOC, Tables and Figures with Charts which is spread across 116 Pages that provides exclusive data, information, vital statistics, trends, and competitive landscape details in this niche sector.

This research report is the result of an extensive primary and secondary research effort into the Pilot Type Pressure Relief Valve market. It provides a thorough overview of the market"s current and future objectives, along with a competitive analysis of the industry, broken down by application, type and regional trends.It also provides a dashboard overview of the past and present performance of leading companies. A variety of methodologies and analyses are used in the research to ensure accurate and comprehensive information about the Pilot Type Pressure Relief Valve Market.

The Global Pilot Type Pressure Relief Valve market is anticipated to rise at a considerable rate during the forecast period, between 2023 and 2028. In 2021, the market is growing at a steady rate and with the rising adoption of strategies by key players, the market is expected to rise over the projected horizon.

Due to the COVID-19 pandemic, the global Pilot Type Pressure Relief Valve market size is estimated to be worth USD million in 2022 and is forecast to a readjusted size of USD million by 2028 with a CAGR of % during the review period. Fully considering the economic change by this health crisis, DNBelow =20 accounting for % of the Pilot Type Pressure Relief Valve global market in 2021, is projected to value USD million by 2028, growing at a revised % CAGR in the post-COVID-19 period. While Oil and Gas segment is altered to an % CAGR throughout this forecast period.

China Pilot Type Pressure Relief Valve market size is valued at USD million in 2021, while the US and Europe Pilot Type Pressure Relief Valve are USD million and USD million, severally. The proportion of the US is % in 2021, while China and Europe are % and % respectively, and it is predicted that China proportion will reach % in 2028, trailing a CAGR of % through the analysis period. Japan, South Korea, and Southeast Asia are noteworthy markets in Asia, with CAGR %, %, and % respectively for the next 6-year period. As for the Europe Pilot Type Pressure Relief Valve landscape, Germany is projected to reach USD million by 2028 trailing a CAGR of % over the forecast period.

The global key manufacturers of Pilot Type Pressure Relief Valve include Curtiss Wright Corp., GE Co., LESER GmbH and Co. KG, Crompton Greaves Ltd, Pentair Ltd., Weir Group PLC, Alfa Laval AB, Bopp and Reuther Sicherheits- und Regelarmaturen GmbH and Crane Co., etc. In 2021, the global top five players have a share approximately % in terms of revenue.

In terms of production side, this report researches the Pilot Type Pressure Relief Valve capacity, production, growth rate, market share by manufacturers and by region (region level and country level), from 2017 to 2022, and forecast to 2028.

In terms of sales side, this report focuses on the sales of Pilot Type Pressure Relief Valve by region (region level and country level), by company, by Type and by Application. from 2017 to 2022 and forecast to 2028.

Pilot Type Pressure Relief Valve market is segmented by Type and by Application. Players, stakeholders, and other participants in the global Pilot Type Pressure Relief Valve market will be able to gain the upper hand as they use the report as a powerful resource. The segmental analysis focuses on production capacity, revenue and forecast by Type and by Application for the period 2017-2028.

Use of Oil and Gas, Power, Chemical, Food and Beverages, Pulp and Paper, Pharmaceuticals and in multiple sectors has led to significant growth in demand for Pilot Type Pressure Relief Valve in the market

This Pilot Type Pressure Relief Valve Market Research/Analysis Report Contains Answers to your following Questions ● What are the global trends in the Pilot Type Pressure Relief Valve market? Would the market witness an increase or decline in the demand in the coming years?

● What is the estimated demand for different types of products in Pilot Type Pressure Relief Valve? What are the upcoming industry applications and trends for Pilot Type Pressure Relief Valve market?

● What Are Projections of Global Pilot Type Pressure Relief Valve Industry Considering Capacity, Production and Production Value? What Will Be the Estimation of Cost and Profit? What Will Be Market Share, Supply and Consumption? What about Import and Export?

● What are the factors contributing to the final price of Pilot Type Pressure Relief Valve? What are the raw materials used for Pilot Type Pressure Relief Valve manufacturing?

● How big is the opportunity for the Pilot Type Pressure Relief Valve market? How will the increasing adoption of Pilot Type Pressure Relief Valve for mining impact the growth rate of the overall market?

Our research analysts will help you to get customized details for your report, which can be modified in terms of a specific region, application or any statistical details. In addition, we are always willing to comply with the study, which triangulated with your own data to make the market research more comprehensive in your perspective.

12.8.4 Bopp and Reuther Sicherheits- und Regelarmaturen GmbH Pilot Type Pressure Relief Valve Product Model Numbers, Pictures, Descriptions and Specifications

Series 437Materials How to Order Numbering System Article Numbers Available Connections Dimensions and Weights Pressure Temperature Ratings Accessories and Options Caps and Levers Metal Seat Soft Seal Heating Jacket Spare Parts Approvals Series 437 Capacities Type 437 Capacities Type 438 / 439 Specification Sheet

Series 459Materials How to Order Numbering System Article Numbers Available Connections Dimensions and Weights Pressure Temperature Ratings Accessories and Options Caps and Levers Balanced Bellows Metal Seat Soft Seal Heating Jacket Lift Indicator Spare Parts Approvals Series 459 Capacities Series 459 Specification Sheet

LESER s compact performance valves are spring loadedsafety relief valves of specially compact design, developed in close cooperation with plant engineers and service specialists to protect special processes and installations against overpressure. Extensive testing at the LESER ASMEcertified test lab together with up to date manufacturing processes ensure the reliability of these state of the art products.

LESER s compact performance valves are designed andmanufactured to highest standards and compliant with and approved according to ASME (Sec. VIII, Div. 1), the Canadian CRN, the European PED standard (CE), the German AD 2000Merkblatt A2 and those of many other countries, covering requirements from end-users, OEM s and engineering companies worldwide.

Features and BenefitsLESER s compact performance valves cover a large variety of types, materials and options to fit any application: Scope of Design q Four valve sizes from 1/2 through 11/2 q Four orifice sizes from 0.3*D through F q Threaded or flanged connections ANSI or DIN, Inlet rating: class 150# to 2500# q Standard metal sealing: Type 437 and Type 459 or q Soft seal: Type 438, 439 and 462 q Optional stainless steel bellows for back pressure compensation q Packed or plain lifting lever or gastight cap q Heating jacket available for high viscosity fluids Compact design and High Performance q Single trim for steam, gas and liquid for less spare parts and easier maintenance q Broad set pressure range up to 11600 psig q Self-draining body design, avoids residues and reduces corrosion q One-piece spindle reduces friction q Unobstructed seat bore for maximum capacity compared to nominal size q Heavy duty design Type 459M q Various materials: chrome steel, stainless steel, Monel or Hastelloy q All parts machined from bar stock for complete valves from special materials within short time q Variety of capacities and versions, multiple choice of connections to fit any application Ease of plant design, installation, operation and maintenance q Replaceable nozzle and disc q Hardened or optional stellited metal sealing for longer product life q Soft seat for superior tightness q Ringless design, no adjustments

Common Features q Compact design q High capacity compared to nominal sizes: for most common valve size 3/4 x 1 up to 1.5 D-orifice capacity * q Four different orifice sizes available q Wide range of set pressures q Optional balanced bellows q Three body materials: cast iron, carbon steel, stainless steel q Various connections

Selection of Threaded Safety Relief ValvesCriteria Set Pressure High Flow Capacity is required > 2700psig > 6000psig D Orifice F Orifice Series Type 437 1 437 438 439 459 1 459 462 Flanged SRV e.g. 526

Material Code 3 Body Material Chrome Steel 4 Body Material Stainless Steel Valve Code Identifies valve size, body material and orifice, refer to page 14. Code for lifting device 2 Screwed cap H2 4 Packed lever H4

The LESER metal seats (disc and nozzle) are lapped to optical flatness to ensure a tight shut off. LESER safety relief valves are supplied with a standard leak tightness according to API 527. Type 4373 Standard material for the disc is a hardened stainless steel. The combination of a hard disc material and a softer seat material (316L) provides for improved wear resistance and longer product life. Type 4374 Disc and seat are provided in 316L material for highest corrosion resistance. Any other material which is available from bar stock can be supplied as well (e.g. Hastelloy, Monel, Alloy20,). Metal seat

Application Pressure relief valves in systems to be protected from media which are viscous, sticky or have a tendency to crystallize out of solution can be fitted with a heating jacket. For type 437 the outlet body is fitted with a fabricated heating jacket. The position of the heating connections is shown in figure 1.

Discs Type 437 metal to metal seat (Item 7)Valve Size all Orifice [Inch2 ] 0.122 Type 4373 Hardened stainless steel 200.8739.9000 Type 4374 Stainless Steel 316L 200.8749.9000

Discs Type 438 soft seal with o-ring, disc material: 316L (Item 7)Valve Size all (standard version) all (long version) Orifice [Inch2 ] O-ring size ARP-no.7

Discs Type 439 with vulcanized soft seal (Item 7)Valve Size Orifice [Inch2 ] CR Neoprene K 200.9049.9051 EPDM Ethylene F 200.9049.9041 FPM (FKM) Viton L 200.9049.9071 NBR Nitrile N 200.9049.9081 FFKM ISOLAST C 200.9049.9091

Company: Location: Name: Reference: GENERAL 1 s Item No.: 2 s Tag No.: 3 s Customer: 4 q Equipment: 5 q Enquiry/Order No.: 6 q Delivery time: 7 q Number of valves: 8 q Number of spare valves: SERVICE CONDITIONS s Steam (S) 11 s Fluid and state: 12 s Molecular weight: 13 q Coefficient C: 14 q Ratio of specific heats k: 15 q Compressibility factor Z: 16 s Spec. gravity / units: 17 q Viscosity / units: 18 s Relieving temperature / units: 19 s Required capacity / units: VALVE CONSTRUCTION 27 q Orifice Designation: 28 q Connection inlet 29 q Size: 30 q Thread type or Flange class: s RJ 31 q Facing type: s RF

MATERIALS 32 q LESER Material Code s 3: Chrome steel 33 q LESER Type: s 437 s 438 s 439 34 s Inlet body: 35 q Outlet body: 36 q Disc (Type 437): s SS hardened s 316L q s other: ACCESSORIES AND OPTIONS 40 s Lifting lever: s packed H4 41 q Others (specify): SIZING AND SELECTION 42 v Required orifice area / units: 43 v Selected orifice area / units: 44 v Coeff. of discharge: 45 v Calculated capacity / units: Order Code s cap H2

Material Code 2 Body Material Carbon Steel 3 Body Material SG iron 4 Body Material Stainless Steel Valve Code Identifies valve size, body material and orifice, refer to page 14.

Application Bellows protect the guides, moving parts and the spring from dirt, corrosion, impurities or temperature to guarantee the proper function of the safety relief valve. Additionally they provide for back pressure compensation 1. Design Series 459 with balanced bellows is provided with a bonnet spacer to house the bellows. The spacer serves for cooling and shields the bellows against turbulences during discharge to avoid vibration and to guarantee longer lifetime.

The bellows for type 459/462 is back pressure compensating for orifice size 0.206 Inch2 (133 mm2). It is over compensating for orifice size 0.099 Inch2 (63,6 mm2) and under compensating for orifice size 0.373 Inch2 (241 mm2). Please ask factory for details. 2 Type 4594 with heavy duty body: up to 1022 F, the temperature limits for type 462 depend on other parts e.g. soft seal materials. 3 The so called built up back pressure limit defines limit for which the proper function of the pressure relief valve is ensured. The superimposed back pressure limit of a bellows refers only to the static stability of the bellows design and does not consider the influence of the backpressure on the opening and closing of a pressure relief valve.

The LESER metal seats (disc and nozzle) are lapped to optical flatness to ensure a tight shut off. LESER safety relief valves are supplied with a standard leak tightness according to API 527. Type 4592 / Type 4593 Standard material for the disc is a hardened stainless steel. The combination of a hard disc material and a softer seat material (316L) provides for improved wear resistance and longer product life. Type 4594 Disc and seat are provided in 316L material for highest corrosion resistance. Any other material which is available from bar stock can be supplied as Monel, well (e.g. Hastelloy, Alloy20,). Metal seat

Application Pressure relief valves in systems to be protected from media which are viscous, sticky or have a tendency to crystallize out of solution can be fitted with a heating jacket. For type 459 the outlet body is fitted with a fabricated heating jacket. The position of the heating connections is shown in the drawing.

Balanced Bellows Design For safety relief valves with balanced bellows, the bonnet spacer required to house the bellows is fitted with an additional heating jacket. Both heating jackets are joined by a tubing.

Lift indicators are an important component for automation. They are used to monitor operating status. As an option, Series 459 can be provided with an inductive proximity switch. The lift indicator will indicate an opening of the pressure relief valve when the vessel pressure has increased so that the valve opens with a pop. LESER provides DC proximity switches type N using two-wire technology. These intrinsically safe proximity switches can be used in explosion hazard area zone 0. Other types of switches can be used as well. The lift indicator option is available for series 459 in combination with the packed lever H4 either with or without proximity switch. The connection size is M18 x 1. A = closed position B = open position

Company: Location: Name: Reference: GENERAL 1 s Item No.: 2 s Tag No.: 3 s Customer: 4 q Equipment: 5 q Enquiry/Order No.: 6 q Delivery time: 7 q Number of valves: 8 q Number of spare valves: SERVICE CONDITIONS 11 s Fluid and state: s Steam (S) 12 s Molecular weight: 13 q Coefficient C: 14 q Ratio of specific heats k: 15 q Compressibility factor Z: 16 s Spec. gravity / units: 17 q Viscosity / units: 18 s Relieving temperature / units: 19 s Required capacity / units: VALVE CONSTRUCTION 27 q Orifice Designation: 28 q Connection inlet 29 q Size: 30 q Thread type or Flange class: 31 q Facing type: s RF s RJ

MATERIALS 32 q LESER Material Code s 2: Carbon Steel 33 q LESER Type s 459 s 462 34 s Inlet Body: 35 q Outlet Body: 36 q Bonnet: 37 q Disc (metal): s SS hardened s 316L s other: ACCESSORIES AND OPTIONS 42 s Lifting lever: s plain H3 s packed H4 s cap H2 43 q Test gag: s yes s no SIZING AND SELECTION 46 v Required orifice area / units: 47 v Selected orifice area / units: 48 v Coeff. of discharge: 49 v Calculated capacity / units: Order Code

First in safety a not so brief history of LESERHistoryThe company started in 1818 as a brass foundry and over the decades developed a product portfolio of components for mechanical equipment and machines during the industrial revolution. At first LESER specialized on tough applications and its level gauges for steam boilers were famous. Soon, the company delivered their first safety valve and as a consequence of quick growing industrialization and improving demand for safety, LESER rapidly became the specialist for safety valves.

Safe solutions from the specialistToday, LESERs product range includes 23 different designs with a variety of materials and sizes from 1/2 to 16, providing safe solutions for almost every application with q Full lift safety valves q High-pressure safety valves q Safety valves according to API 526 q Relief and safety relief valves q Clean service safety relief valves q Safety valves for critical service conditions q Safety valves according to special standards and regulation q Safety valves with supplementary pneumatic load q Special versions

Where to find LESERHeadquartered in Germany, with a state-of-the-art factory and more than 290 employees, LESER is present through subsidiaries and qualified partners in over 40 countries, providing products and services worldwide.

The Safety ValveLESER LLC1664 Headland Drive Fenton, MO 63026 Phone: 636 - 343 - 8766 636 - 326 - 9185 Fax: e-mail: sales@leserusa.com www.leserusa.com