Solutions for high plant efficiency

LESER Pilot operated safety valves

• Highest blow-off capacity of all series
• Tightness right up to set pressure
• Operating pressures up to 96% of the set pressure
• Back pressures up to 70% of the set pressure
• Backflow preventer integrated as a standard component 
• Integrated Piping prevents damage and freezing

Supplementary Loading System

Equipment that enables the following safety valve characteristics:

• Tightness right up to set pressure
• Operating pressures up to 97% of the set pressure 
• Low loss of medium due to short opening times
• Function test and valve adjustment possible during operation
• Suitable for all media temperatures

Industries

• Chemical 
• Oil & Gas 
• Petrochemical 
• Energy 
• Technical Gases 
• LNG and LPG 
• General industries 

Approvals

LESER High Efficiency safety valves are designed, marked, produced and approved according to the requirements of the following regulations:

Valve Types

• Type 811 
• Pilot operated / Pop Action
• DN 25 - DN 200 (1" - 8")

• Type 821 
• Pilot operated / Modulate Action
• DN 25 - DN 200 (1" - 8")

• Type 702, 712, 714, 731 
• Supplementary Loading System
• (additional option for safety valves)

Technical data pilot operated safety valves

• Nominal Diameter at Inlet
  • DN 25 - DN 200 | 1" - 8"
• Actual Orifice Diameter d₀
  • 11 mm - 180 mm | 0.433 in - 7.087 in
• Actual Orifice Area A₀
  • 95 mm² - 25,446.9 mm² | 0.147 in² - 39.443 in²
• Pressure
  • 2.5 bar - 426 bar | 36 psig - 6170 psig
• Temperature (in accordance with DIN EN)
  • -48 °C to 200 °C | -54.4°F to 392°F
• Body Material
  • 1.0619, 1.4408 | SA 352 LCB, SA 216 WCB, SA 351 CF8M
• Valve Connection
  • Flange in accordance with DIN EN 1092, ASME B 16.5 or JIS 2220
• Load Type
  • Medium controlled

Products range

High Efficiency Type 811

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 seal sealings or metal-to-metal sealing

High Efficiency Type 821

LESER Type 821 Modulate Action pilot-operated safety valves open in proportion to system overpressure to decrease product loss, reduce emissions and limit noise. Set pressure is not affected by back pressure. The modulate action pilot control can be vented to the outlet of the main valve for additional safety

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
• Typical blowdown max. 7%
• Complete stainless steel construction of pilot valve
• Certified for air, gas and liquid service (ASME Section VIII) and air, gas, steam and liquid service (DIN EN ISO 4126, AD 2000-Merkblatt)

Soft seal sealings or metal-to-metal sealings

Case Study

LESER LNG POSVs support high plant efficiency in liquefaction process

• Industry/Application:
  • LNG / natural gas liquefaction plant
• LESER Solution:
  • POSV, Compact Performance, API
• Customer since:
  • For more than 20 years
• Quantity of Valves Supplied:
  • 288 safety valves: 6 Type 811, 47 Type 459 and 235 Type 526

The Challenge
The liquefaction process must be designed efficiently so that the LNG can be offered economically. The necessary cryogenic media temperatures of -161 to -164 °C represent a challenge for the technical design of the individual components in the plant. This also applies in particular to the safety valves, which must function reliably as the final protection in the event of overpressure, even at the cryogenic process and Russian ambient temperatures. 
Linde expected its suppliers to provide a reliable and punctual delivery in addition to solving the technical requirements.
 
Why did the customer choose LESER products?
LESER valves meet all requirements for use in natural gas liquefaction plants and offer a complete product range. The valves are designed in the low-maintenance “Durable Design” and can be adapted to the plants by various options.