Advance Valve Product Information

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Safety Relief Valve

Type 441/442

Full Flanged Safety Valves with Flanged Connections

Full lift safety valves 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.

There are four series available:

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.

Type 441/442 DIN

Cast construction with DIN flanges.
Two body materials: stainless steel and carbon steel.

Type 441/442 "XXL"

Robust welded construction with DIN or ANSI flanges.
Welding procedures to EN and ASME standards.
Two body materials: stainless steel and carbon steel.

Type 444

Welded construction using deep drawn body parts [3] (material: 1.4404/316L; plate thickness >4 mm); a principal characteristic feature is the smooth surface finish.

 Technical Information
Type Bonnet Flange ANSI B 16.5 Flange DIN 2501 Main Characteristic
441 ANSI closed #150...#300 1"...8" - - Cast Construction, semi nozzle
442 ANSI open
441 DIN closed - - 16...40 20...200
442 DIN open
441 "XXL" closed #150...#300 8"...16" 10...25 200...400 Welded construction, full nozzle
442 "XXL" open