Series-LF441

Supported Applications

The Weiss LF441 Series consists of 4" liquid-filled pressure gauges designed for general service conditions. These instruments measure pressure, vacuum, or compound ranges on air, oil, water, gas, and other media that do not attack brass. Documented applications include compressors, pumps, hydraulic equipment, plumbing, heating systems, and outdoor installations.

Operating Conditions & Performance

The LF441 series operates within a process temperature range of -40-140°F (-40-60°C) and an ambient operating temperature of -40-140°F (-40-60°C). Accuracy is rated at ±1.0% Full Scale, conforming to ASME B40.100 Grade 1A standards. The gauges feature a glycerine fill fluid to dampen vibration and pulsation effects.

Standard measurement ranges cover vacuum (30" Hg/0), compound scales (e.g., 30" Hg/0/15 psi & kPa through 30" Hg/0/300 psi & kPa), and pressure-only spans from 0/15 psi & kPa up to 0/10,000 psi & kPa. The series supports a maximum continuous operating pressure of Up to 1000 psi for standard configurations.

Configuration Options

The LF441 series is configured with specific range codes and connection types as defined in the ordering guide (e.g., LF441 - - ). Key construction features include:

• Housing & Window: 4" Type 304 stainless steel thin line case with a clear acrylic window and crimped, polished stainless steel ring.
• Movement Components: Phosphor bronze tube (sensing element), brass socket with threaded restrictor, white aluminum dial with black and red markings, and a black anodized aluminum pointer.
• Process Connection: Standard 1/4 NPT Lower connection; variants include codes such as "4L" for lower mount configurations.

The series supports several optional features and accessories. Available options include back flanges, 1/2 NPT connections, lead-free brass internals for potable water applications, custom dial markings, and alternative scale ranges (PSI only, PSI & BAR, or PSI & kg/cm²).

Key Product Differences

Variants within the LF441 series are distinguished by their measurement range codes and connection suffixes. The standard catalog includes pressure-only models ranging from 0/15 psi to 0/10,000 psi (e.g., model code "015" through "10000") as well as vacuum and compound ranges denoted by prefixes such as "VAC", "V15", "V30", up to "V300". Connection suffixes like "4L" indicate the standard ¼ NPT Lower mounting orientation, while other connection codes may denote alternative configurations.

Installation notes specify that Weiss gauges should always be installed with a shut-off valve for removal. For applications involving pressure spikes, surges, or pulsations, a pressure snubber is recommended in conjunction with the gauge. In steam service, protection from excessive temperature via a coil type siphon is required.