LESER Type 811 821 High Efficiency Safety Valves DN25 DN200 Pop Action Gas Pilot Operated Safety Relief Valve

The LESER Type 811/821 Pilot-Operated Safety Relief Valves are engineered for high-efficiency pressure protection in demanding industrial applications. The Type 811 features a rapid pop action for abrupt opening, ideal for gas applications, while the Type 821 offers modulate action for proportional opening, minimizing product loss and noise in vapor, gas, and liquid systems. Both valves comply with API 526 standards, ensuring 100% compatibility with high-pressure systems up to 426 bar. With exceptional tightness up to 97% of set pressure and robust construction, these valves are perfect for industries like chemical processing, oil and gas, and LNG/LPG operations.

• High Efficiency Design: Type 811 (Pop Action) opens abruptly, Type 821 (Modulate Action) opens proportionally for reduced emissions and noise.
• API 526 Compliance: Ensures compatibility with industry standards for seamless integration.
• Exceptional Tightness: Maintains tightness up to 97% of set pressure for minimal leakage.
• High Back Pressure Handling: Operates with back pressures up to 70% of set pressure.
• Wide Pressure Range: Supports 2.5–426 bar (36–6170 psig) for versatile applications.
• Robust Materials: Constructed with SA 216 WCB, SA 351 CF8M, and optional high-alloy materials like Monel and Hastelloy.
• Integrated Backflow Preventer: Standard component enhances safety and reliability.
• Supplementary Loading System: Enables function testing and adjustment during operation.

The LESER Type 811/821 valves are optimized for high-pressure safety applications:

• Chemical Industry: Protects reactors and waste gas systems with high-pressure relief.
• Oil and Gas: Ensures safety in upstream, midstream, and downstream processes.
• Petrochemicals: Handles high-pressure refining and pipeline systems.
• Energy Sector: Safeguards steam and gas turbine systems.
• LNG and LPG: Provides reliable pressure relief for liquefied gas applications.

Type 811 offers pop action for abrupt opening in gas applications, while Type 821 uses modulate action for proportional opening, reducing emissions and noise.

Yes, both Type 811 and 821 meet API 526 standards for full compatibility.

Yes, they support back pressures up to 70% of set pressure, outperforming spring-loaded valves.

They are certified to ASME Sec. VIII Div. 1, PED, DIN EN ISO 4126-4, AD 2000-Merkblatt A2, AQSIQ, EAC, and classification societies (LR, RINA, DNV GL, BV).

They maintain tightness up to 97% of set pressure, with increasing closing forces near set pressure.

For more information about the LESER Type 811/821 Safety Relief Valves, pricing, or to request a demo, contact our team:

• Email: edward.zhao@gongboshi.com
• Phone: +8615000725058
• Website: https://www.shgongboshi.com/

• LESER High Performance Valves: For high-pressure and high-capacity applications.
• LESER Compact Performance Valves: For smaller systems requiring tight shutoff.
• LESER API Series: API-compliant valves for oil and gas industries.
• LESER Clean Service Valves: For hygienic applications in pharmaceuticals and food processing.