The LESER Type 441/442 Full Lift Safety Relief Valves are designed for high-capacity pressure relief in demanding industrial applications. Engineered to open rapidly within a 5% overpressure range, these spring-loaded valves ensure maximum mass flow discharge for steam, gases, and liquids. Compliant with standards like PED, ASME Section VIII, and AD 2000-Merkblatt A2, they are available in DIN and ASME flange configurations, making them a versatile choice for industries such as chemical processing, petrochemicals, and power generation. With robust construction and a high discharge capacity, the Type 441/442 valves are among the best-selling spring-loaded flange safety valves worldwide.
| Parameter | Type 441/442 DIN | Type 441/442 ANSI | Type 441/442 XXL |
|---|---|---|---|
| Set Pressure (CE) | 0.1–40 bar (1.5–580 psig) | 1–40 bar (15–580 psig) | 0.2–25 bar (2.9–362 psig) |
| Temperature Range (CE) | -270°C to 450°C (-454°F to 842°F) | -268°C to 538°C (-450°F to 1000°F) | -45°C to 400°C (-49°F to 752°F) |
| Nominal Diameter at Inlet | DN 20–DN 400 (NPS 3/4–16) | NPS 1–8 | DN 200–400 (NPS 8–16) |
| Actual Orifice Diameter (d₀) | 18–295 mm (0.71–11.61 in) | 18–165 mm (0.71–6.5 in) | 165–295 mm (6.5–11.61 in) |
| Actual Orifice Area (A₀) | 254–68347 mm² (0.394–105.938 in²) | 254–21382 mm² (0.394–33.142 in²) | 21382–68347 mm² (33.142–105.938 in²) |
| Flange Rating Inlet | PN 10–PN 40 | ASME Class 150–300 | PN 10–PN 25, ASME Class 150–300 |
| Body Material | 0.6025, 0.7043, 1.0619, 1.4408 (Gr. 60-40-18, SA 216 WCB, SA 351 CF8M) | SA 216 WCB, SA 351 CF8M | 1.0619, 1.4408 (SA 216 WCB, SA 351 CF8M) |
| Bellows Material (Optional) | Stainless steel, elastomer | Stainless steel, elastomer | Stainless steel |
| Seat Gasket | Metallic, sealing plate, O-ring | Metallic, sealing plate, O-ring | Metallic, sealing plate |
| Load Type | Spring-loaded | Spring-loaded | Spring-loaded |
The LESER Type 441/442 valves are engineered for high-capacity pressure relief in various industries:
They are suitable for steam, gases, and liquids, per AD 2000-Merkblatt A2 standards.
They open rapidly within a 5% overpressure range, ensuring maximum mass flow discharge.
Yes, they meet PED, ASME Section VIII, AD 2000-Merkblatt A2, CRN, AQSIQ, EAC, and classification society standards.
The XXL variant supports larger nominal sizes (DN 200–400) for high-flow applications.
The rolled-in seat and self-draining body design minimize wear and residue buildup.
For more information about the LESER Type 441/442 Safety Relief Valves, pricing, or to request a demo, contact our team:
