Ashcroft 1279 Duragauge Pressure Gauge

Overview

The Ashcroft 1279 Duragauge is a 4½-inch ASME-style process pressure gauge built for plants that need dependable, high-accuracy pressure indication in demanding service. The 1279 pressure gauge uses a solid-front case design with a blow-out back, so any overpressure event vents safely away from the operator rather than through the dial face, a safety feature that has made the Duragauge series a standard specification across refineries and chemical plants. Internally, the gauge relies on a Bourdon tube movement built from 400-series stainless steel with a Teflon-coated pinion, giving the 1279 gauge long service life and a stable, micrometer-adjustable pointer even after repeated pressure cycling.

Seven Star LLC is an experienced supplier of the Ashcroft 1279 Duragauge pressure gauge to industrial buyers throughout Oman and the GCC, giving plant engineers a verified sourcing route for a gauge that is widely specified on process instrumentation datasheets across the region. Because the 1279 gauge is offered dry, field-fillable, liquid-filled or hermetically sealed, one gauge family can be matched to changing site conditions.

Measurement and Operating Principle

Like other Bourdon tube gauges, the Ashcroft 1279 converts applied process pressure into the mechanical deflection of a curved, flattened tube sealed at one end. As pressure rises, the tube tries to straighten, and that motion is transferred through a rotary movement to the pointer across the dial. The 1279 Duragauge achieves ±0.5% of span accuracy, meeting ASME B40.100 Grade 2A, across pressure ranges spanning vacuum and compound service up to 30,000 psi, which lets one gauge platform cover everything from low-pressure utility lines to high-pressure hydraulic and wellhead service.

The rotary, adjustable movement inside the 1279 gauge is built to resist wear from continuous pressure cycling, and the micrometer pointer adjustment allows field technicians to fine-tune indication without opening the movement. Dampening options include liquid fill, a throttle screw, or Ashcroft’s Plus! Performance package, each aimed at reducing pointer flutter on pulsating or vibrating service so operators get a readable, stable indication rather than a blurred needle.

Engineering Design of the Ashcroft 1279

The 1279 Duragauge case is available in a 4½-inch phenolic housing chosen for its chemical resistance, paired with a standard glass window, with acrylic, shatterproof glass or non-glare glass available as options depending on the site environment. Process connections include ¼-inch NPT male, ½-inch NPT male, and a 9/16-18 UNF-2B high-pressure fitting, with lower or back connection orientation and stem, surface, flush, pipe, or remote mounting options to fit almost any panel or process tap layout. Wetted parts are available in 316L stainless steel, supporting NSF-61 compliant builds for potable water and other purity-sensitive applications.

Weather protection depends on configuration: the standard case is not sealed and is intended for weather-protected locations, while liquid-filled or field-fillable versions reach IP66 or NEMA 4X, and hermetically sealed versions reach IP66 as well, giving specifiers a clear path to outdoor or washdown-rated installations. Ashcroft backs the 1279 gauge with a ten-year pressure system warranty, reflecting the durability built into the Bourdon tube and movement assembly.

Key Features

• 4½-inch ASME B40.100 Grade 2A gauge with ±0.5% of span accuracy
• Solid-front case with blow-out back for operator safety under overpressure
• Pressure ranges from vacuum and compound service up to 30,000 psi
• 400-series stainless steel movement with Teflon-coated pinion for long service life
• Available dry, field-fillable, liquid-filled or hermetically sealed
• 316L stainless steel wetted parts available for NSF-61 compliant installations
• Multiple process connection sizes and mounting styles for flexible installation
• Ten-year pressure system warranty backing the Bourdon tube and movement

Industrial Applications

The Ashcroft 1279 pressure gauge is specified across refineries, chemical and petrochemical plants, offshore oil rigs, water and wastewater pressure control, mining and metals, and equipment skids wherever a safe, accurate process pressure reading is required at the panel or process tap. The datasheet also lists cryogenics, pulp processing and specialized OEM equipment among typical uses, where high pressure and mechanical vibration would quickly degrade a lower-grade indicator.

Process plants across Oman and the GCC, including facilities in Muscat, Sohar, and Salalah, rely on the 1279 Duragauge for both new installations and instrumentation replacement programs, and Seven Star LLC supports these projects as a trusted supplier of genuine Ashcroft pressure gauges. That includes helping engineers match wetted material, range, and connection size to the exact process tap before the gauge is ordered, avoiding costly re-specification once equipment reaches site.

Technical Specifications

Materials, Temperature Limits and Environmental Performance

Material selection on the Ashcroft 1279 extends well beyond the 316L stainless steel option already noted. The Bourdon tube is available in 316L stainless steel, 316 stainless steel, K-Monel® 500, or phosphor bronze, and the socket in 316L stainless steel, steel, Monel® 400, or brass, with the tube-to-socket joint either welded or silver brazed depending on the material pairing chosen. Welded pressure systems tolerate short-term exposure to roughly 750°F (400°C) and silver-brazed joints to 450°F (232°C) before the joint itself ruptures, a margin worth knowing when gauges are specified into fire-exposed process areas. The case itself is phenolic, with a threaded polycarbonate ring and a polycarbonate pressure relief back, both meeting UL 94 V-0, and the dial is aluminium carrying a black scale on a white background.

Ambient and process temperature limits on the 1279 gauge depend on the fill selected. Dry gauges are rated -20°F to 200°F ambient and -20°F to 250°F process; glycerin-filled units 20°F to 150°F; and silicone, Halocarbon®, or PLUS!™ Performance builds -40°F to 150°F ambient with process service to 200°F. Indication shifts approximately 0.4% for every 25°F of deviation from the 68°F reference temperature, a correction worth applying when the gauge sits on hot service in Omani summer ambient conditions.

Specification and Ordering Notes

Process connections can be ordered lower, back, top, or side at the 3 o’clock or 9 o’clock position, giving panel designers more freedom than the lower-and-back pairing alone. Optional extras on the Ashcroft 1279 Duragauge include custom dial printing, safety glass, the DuraVis™ retroreflective dial for low-light plant rooms, oxygen service cleaning, traceable calibration certificates, and an IP65 dry case rating, while siphons, needle valves, and snubbers are offered as companion accessories for steam and pulsating service. The datasheet lists CE, CRN and NSF-61 approvals, so it can be specified into projects that require documented pressure-equipment conformity.

Get a Quote

Seven Star LLC is an experienced supplier of genuine Ashcroft 1279 Duragauge pressure gauges for buyers across Oman and the GCC. Contact our instrumentation team for range selection, material specification, and a formal quotation for your Ashcroft 1279 gauge requirement.

Ordering Code Structure

The 1279 is configured through a model code that starts with 451279 for the 4.5 inch phenolic-case process gauge. The system material code sets the tube and connection: A is a bronze tube with brass connection up to 1,000 psi, P is a K-Monel 500 tube with Monel 400 connection up to 30,000 psi, R is a 316L tube with steel connection up to 20,000 psi, and S is a 316 tube with 316L connection up to 20,000 psi and NSF-61 compliance.

The case design is S for a solid front dry case, SH for dry and hermetically sealed, or SL for liquid filled with glycerin as standard. Connection sizes include 1/4 NPT, 1/2 NPT and the 9/16-18 UNF-2B Aminco fitting, which is standard above 20,000 psi, and the connection can be lower, back, side at 3 or 9 o'clock, or top.

Options and Special Preparation

Ashcroft lists a wide range of options for the 1279, including PLUS! Performance dampening, silicone or Halocarbon fills, overload and underload stops, maximum and minimum pointers, red set hands, safety or non-glare glass, and the DuraVis retroreflective dial. Tags, custom dial marking and a 2-pipe mounting bracket are also available.

For special service, options cover oxygen cleaning to ASME B40.100 level IV (not available above 10,000 psi), mercury-free gauges, absolute-pressure calibration with the pointer offset by 14.7 psi, material certification per EN 10204 3.1, positive material identification, hydrostatic or pneumatic testing and traceable calibration certificates.

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