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Brand: LESER
LESER Type 444 Stainless Steel Full Lift Safety Valve
Description
Compact stainless steel safety valve for pressures up to 16 bar
The LESER Type 444 is a full-lift safety valve in the LESER High Performance series with a deep-drawn 316L stainless steel body, offered with DIN flanges (PN 16) or ANSI flanges (Class 150). It is aimed at applications up to 16 barg where a compact, lightweight stainless valve is wanted, for example in textile dyeing machines, filter constructions and OEM equipment. The valve relieves within a 5% pressure increase and covers nominal sizes from DN 25 inlet up to DN 80.
The design is conventional, with a closed bonnet and a metal seat. Valve body, seat, disc, guide, spindle and bonnet are all 1.4404 / 316L, with a PTFE-glass guide bushing, EPDM-FDA O-rings and a stainless steel spring. LESER supplies its metal-seated valves with Nanotightness as standard, which it states exceeds the functional tightness requirement of API 527 by 50%. A packed lever (H4) or a cap (H2) is available.
Technical specifications
| Parameter | Specification |
|---|---|
| Type | LESER Type 444 DIN / Type 444 ANSI, full lift, conventional |
| Set pressure (CE) | 0.1 to 16 bar (1.5 to 232 psig) |
| Set pressure (ASME) | 1 to 16 bar (15 to 232 psig) |
| Temperature | -45 to 200 °C (-49 to 392 °F) |
| Orifice letters | G to N |
| Inlet connection | DIN EN 1092 DN 25 to DN 80, PN 16; or ANSI Class 150 |
| Body material | 1.4404 / SA 479 316L |
| Bellows | None available |
| Seat seal | Metal-to-metal |
| Bonnet | Closed; cap H2 or packed lever H4 |
| Delivery time (LESER web page) | 2 weeks for standard configurations |
Sizes and article numbers, DIN version
| Size | Orifice d0 / area A0 | Weight | Article no. (cap / lever) |
|---|---|---|---|
| DN 25 x 50 | 23 mm / 416 mm² | 7 kg | 4444.3642 (H2) / 4444.3644 (H4) |
| DN 40 x 80 | 37 mm / 1075 mm² | 13 kg | 4444.3662 / 4444.3664 |
| DN 50 x 80 | 46 mm / 1662 mm² | 14 kg | 4444.3672 / 4444.3674 |
| DN 65 x 100 | 60 mm / 2827 mm² | 23 kg | 4444.3682 / 4444.3684 |
| DN 80 x 100 (0.1-6.8 bar) | 74 mm / 4301 mm² | 24 kg | 4444.3692 / 4444.3694 |
| DN 80 x 100 (6.81-16 bar) | 74 mm / 4301 mm² | 24 kg | 4444.3702 / 4444.3704 |
The ANSI version is listed in sizes 1 x 2 in. to 3 x 4 in. with article numbers starting 4444.8902. Higher pressure stainless valves are covered by other LESER High Performance types such as the Type 441/442 ANSI valve.
Selection and documents
Valve sizing must follow the required relieving capacity, set pressure and medium, and LESER provides the Valvestar sizing program for this. The attached LESER High Performance extended catalog (07/2016) contains the materials, dimensions, pressure-temperature ratings and options for Type 444. Check the LESER web page for the current data, since the catalog is older. For a quotation, send the article number or size, set pressure, medium and flange standard. Related valves are listed under Safety Relief Valves.
Datasheets & Documents
- Catalog LESER High Performance extended catalog (EN, 07/2016): Types 441, 444, 455, 457 and more Download
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About brand
Safety valves are the whole business at LESER, which traces its origins to Hamburg in 1818. The range runs from small threaded valves to API 526 flanged valves and pilot-operated designs. Seven Star LLC lists LESER safety relief valves across these product groups and sources them, with the manufacturer's documentation, for pressure equipment in Oman.
LESER safety valve product groups
LESER sorts its valves into named groups, and the type number identifies the design:
- API: Type 526 flanged safety relief valves to API 526 dimensions
- High Performance: Type 441/442 flanged valves, and Type 455/456 and 457/458 for high pressure
- Compact Performance: threaded Types 437, 459 and 462
- High Efficiency: pilot-operated safety valves such as the pop action Type 811
- Critical Service: Types 447 and 449 for corrosive media, the 447 with PTFE-lined wetted parts
- Clean Service: hygienic valves for food and pharmaceutical plants
Modulate Action valves and change-over valves, which let one of two safety valves be taken offline, complete the listing.
Where LESER safety valves are used
LESER safety valves protect pressure vessels, heat exchangers, boilers, compressors, pumps and piping against overpressure in oil and gas, refining, petrochemical, power, industrial gas, food and pharmaceutical plants throughout the GCC. Spring-loaded valves are the standard choice. Pilot-operated valves are selected where operating pressure runs close to set pressure or back pressure is high.
Ordering LESER valves: what we need
A safety valve is always built to a set pressure, so a type number alone cannot be quoted. Please send the nameplate data of the existing valve (type, article or job number, serial number, set pressure, orifice) or a full data sheet: medium and its state, set pressure, operating and relieving temperature, back pressure, required capacity, inlet and outlet size and rating, body and trim material, design code (ASME Section VIII or PED) and options such as bellows, lifting lever or sour service materials. We verify the selection against LESER documentation and supply the manufacturer's certificates on request.
Browse LESER products by category: Safety Relief Valves.
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Frequently Asked Questions
What set pressure range does the LESER Type 444 cover?
0.1 to 16 bar (1.5 to 232 psig) according to CE; 1 to 16 bar according to ASME.
What is the body material?
1.4404 / SA 479 316L stainless steel, with a deep-drawn body.
What sizes are available?
DIN inlet DN 25 to DN 80, or ANSI 1 x 2 in. to 3 x 4 in., in orifices G to N.
What temperature range applies?
-45 to 200 °C (-49 to 392 °F).
Is a bellows available?
No. The Type 444 is a conventional design without bellows.
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