Series-NF601

Supported Applications

Weiss Instruments Series NF601 leakproof pressure gauges are stainless steel cased, liquid-filled 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 supports pressure ranges from vacuum to 15,000 psi across various model families within the stainless steel industrial gauge line. Accuracy varies by case size and construction: ±1.6% of span for 2 1/2" models (LF251/LF252/NF252), 1% of span for 4" models (LF441/LF442/NF402), and 1/2% of span for 6" models (LF602/NF602). Wetted materials include Phosphor Bronze, Type 316 Stainless Steel, and Brass. Standard filling medium is glycerine rated from +20°F to +150°F; silicone fill is available as a special order for -40°F/150°F service.

Process connections are provided in 1/4" NPT bottom or center back configurations depending on the specific series. A warning notes that glycerine can combine with strong oxidizing agents including chlorine, nitric acid, and hydrogen peroxide to result in explosion; users should consult the factory for proper filling medium in hazardous service and reference ANSI B40.1 before installation.

Configuration Options

The series encompasses multiple case sizes (2 1/2", 4", 6") with options for liquid-filled or non-liquid filled configurations, crimped ring or bayonet lock rings, and various mounting styles. Available panel mounting options include:

• U-Clamp mounting: Series LF251U, LF252U
• Front Flange mounting: Series LF251F, LF252F, LF442F
• Back Flange mounting: Series LF441BF, LF442BF, LF602BF, NF402BF, NF602BF

Dial materials vary by series; 2 1/2" models feature ABS white dials with black and red markings (psi & kPa), while 4" and 6" models utilize white aluminum dials. Window options include clear acrylic, safety glass, or tempered glass depending on the model.

Key Product Differences

Differences across the series are defined by case size, accuracy class, wetted material composition, and mounting configuration:

• Liquid Filled 2 1/2" (LF251/LF252): Type 304 stainless steel cases with crimped rings. LF251 uses Phosphor Bronze tubes to 6,000 psi and Brass sockets; LF252 utilizes Type 316 Stainless Steel for both tube and socket up to 10,000 psi.
• Liquid Filled 4" (LF441/LF442): Thin line or standard cases with crimped rings. LF441 features Phosphor Bronze tubes and Brass sockets for ranges to 1,000 psi; LF442 uses Type 316 stainless steel wetted parts for ranges up to 15,000 psi.
• Liquid Filled 6" (LF602): Bayonet ring cases with Type 316 stainless steel tubes and sockets; accuracy is 1/2% of span. Ranges extend from vacuum to 15,000 psi.
• Non-Liquid Filled Industrial Cases: Series NF252 (2 1/2"), NF402 (4"), and NF602 (6") feature bayonet lock rings. The NF602 includes a blow out disc on the case back.