Series-NF252

Supported Applications

Weiss Instruments Series NF252 leakproof pressure gauges are stainless steel cased industrial instruments designed for severe applications involving vibration, corrosion, and pulsating conditions. The product overview identifies suitability for agricultural equipment, hydraulic systems, oil field equipment, pumps, compressors, and car wash systems.

Operating Conditions & Performance

The Series NF252 is a 2 1/2" non-liquid filled gauge with Type 304 stainless steel case construction. It features Type 316 Stainless Steel wetted parts, including the tube and socket (with threaded restrictor). The series supports pressure ranges from Vacuum to 6,000 psi, covering vacuum, compound, and pressure applications.

Accuracy for Series NF252 is specified as ±1.6% of span. Process connections are available in 1/4" NPT bottom or center back configurations. The dial consists of ABS material with white background and black/red markings indicating psi & kPa units, protected by a clear acrylic window.

Series Envelope Capabilities

The broader Weiss stainless steel industrial gauge family supports expanded capabilities beyond the NF252 model:

• Ranges: Vacuum to 15,000 psi across various series.
• Accuracy Classes: ±1.6% of span (Series LF251/LF252/NF252), 1% of span (Series LF441/LF442/NF402), and 1/2% of span (Series LF602/NF602).
• Case Sizes: Available in 2 1/2", 4", and 6" diameters.
• Filling Media: Glycerine is standard for liquid-filled models (+20°F to +150°F); Silicone is available as a special order (-40°F to +150°F).

Safety & Standards

The manufacturer advises reading ANSI B40.1 before installation or use due to explosion risks from misuse. A specific warning notes that glycerine can combine with strong oxidizing agents (including chlorine, nitric acid, and hydrogen peroxide) resulting in an explosion; users should consult the factory for proper filling media in hazardous service.

Configuration Options

The Series NF252 is offered as a non-liquid filled gauge with specific construction details:

• Housing: 2 1/2" Type 304 stainless steel case with polished stainless steel bayonet lock ring.
• Movement & Pointer: Stainless steel movement; black anodized aluminum adjustable pointer.
• Dial Markings: psi and kPa units on white ABS dial.

The broader series supports various mounting configurations depending on the specific model family (LF or NF) and case size. Options include direct, wall, or panel mounting styles such as U-Clamp (e.g., Series LF251U/LF252U), Front Flange (e.g., Series LF442F/NF602BF variants in other sizes), and Back Flange.

Wetted Materials by Model

• Series NF252: Type 316 Stainless Steel tube and socket with threaded restrictor.
• Liquid-Filled Variants (LF Series): Phosphor Bronze tubes are used in lower pressure ranges (up to 6,000 psi for LF251), while higher pressures utilize Type 316 Stainless Steel.

Key Product Differences

The Weiss industrial gauge line distinguishes between liquid-filled and non-liquid filled models. The Series NF252 is a non-liquid filled variant, whereas the LF series (e.g., LF251, LF442) are liquid-filled.

Case Size & Accuracy Differences

• 2 1/2" Cases: Series NF252 and LF252 offer ±1.6% of span accuracy; the bayonet ring style is standard for these sizes.
• 4" Cases: Series NF402 (non-filled) and LF442 (liquid-filled) provide 1% of span accuracy with safety glass windows on liquid-filled models.
• 6" Cases: Series NF602 and LF602 offer the highest accuracy at 1/2% of span, featuring tempered or safety glass windows and micro-adjustable pointers. The 6" cases include a blow-out disc for pressure relief in non-filled models.

Mounting & Connection Variations

While Series NF252 supports bottom or center back connections, other series members may be restricted to specific orientations. For example, the 4" LF441 and 6" LF602/NF602 models are listed with 1/4" NPT bottom connections only in their respective specification tables.