Indicate Positive, Negative or Differential, Accurate within 1%
Magnehelic® Differential Pressure Gages is a versatile low differential pressure gauge with a wide choice of 81 models and 27 options to choose from. Applies to a variety of applications.
Features
-
Easy to read gage through undistorted plastic face permits viewing from far away
-
Patented design provides quick response to pressure changes means no delay in assessing critical situations
-
Durable and rugged housing and high-quality components combine to provide longservice life and minimized down-time
-
High accuracy option is twice as accurate as the standard Magnehelic® gage.
-
Bezel provides flange for flush mounting in panel.
-
Clear plastic face is highly resistant to breakage. Provides undistorted viewing of pointer and scale.
-
Precision litho-printed scale is accurate and easy to read.
-
Red tipped pointer of heat treated aluminum tubing is easy to see. It is rigidly mounted on the helix shaft.
-
Pointer stops of molded rubber prevent pointer over-travel without damage.
-
"Wishbone" assembly provides mounting for helix, helix bearings and pointer shaft.
-
Jeweled bearings are shock-resistant mounted; provide virtually friction-free motion for helix. Motion damped with high viscosity silicone fluid.
-
Zero adjustment screw is conveniently located in the plastic cover, and is accessible without removing the cover. O-ring seal provides pressure tightness.
-
Helix is precision made from an alloy of high magnetic permeability. Mounted in jeweled bearings, it turns freely, following the magnetic field to move the pointer across the scale.
-
Calibrated range spring is flat spring steel. Small amplitude of motion assures consistency and long life. It reacts to pressure on diaphragm. Live length adjustable for calibration.
-
Silicone rubber diaphragm with integrally molded O-ring is supported by front and rear plates. It is locked and sealed in position with a sealing plate and retaining ring. Diaphragm motion is restricted to prevent damage due to overpressures.
-
Die cast aluminum case is precision made and iridite-dipped to withstand 168 hour salt spray corrosion test. Exterior finished in baked dark gray hammerloid. One case size is used for all standard pressure options, and for both surface and flush mounting.
-
OVERPRESSURE PROTECTION
Blowout plug is comprised of a rubber plug on the rear which functions as a relief valve by unseating and venting the gage interior when over pressure reaches approximately 25 psig (1.7 bar). To provide a free path for pressure relief, there are four spacer pads which maintain 0.023" clearance when gage is surface mounted. Do not obstruct the gap created by these pads. The blowout plug is not used on models above 180" of water pressure, medium or high pressure models, or on gages which require an elastomer other than silicone for the diaphragm. The blowout plug should not be used as a system overpressure control. High supply pressures may still cause the gage to fail due to over pressurization, resulting in property damage or serious injury. Good engineering practices should be utilized to prevent your system from exceeding the ratings of any component.
-
O-ring seal for cover assures pressure integrity of case.
-
Samarium Cobalt magnet mounted at one end of range spring rotates helix without mechanical linkages.
Product Applications
-
Filter Monitoring
-
Air Velocity with Dwyer Pitot Tube
-
Blower Vacuum Monitoring
-
Fan Pressure Indication
-
Duct, Room or Building Pressures
-
Clean Room Positive Pressure Indication
Specifications
-
Service: Air and non-combustible, compatible gases (natural gas option available). Note: May be used with hydrogen. Order a Buna-N diaphragm. Pressures must be less than 35 psi.
-
Wetted Materials: Consult factory.
-
Housing: Die cast aluminum case and bezel, with acrylic cover, Exterior finish is coated gray to withstand 168 hour salt spray corrosion test.
-
Accuracy: ±2% (-HA model ±1) of FS (±3% (-HA ±1.5%) on -0, -100PA, -125PA, -10MM and ±4% (-HA ±2%) on -00, -60PA, -6MM ranges), throughout range at 70°F (21.1°C).
-
Pressure Limits: -20 in Hg. to 15 psig.† (-0.677 bar to 1.034 bar); MP option: 35 psig (2.41 bar), HP option: 80 psig (5.52 bar).
-
Enclosure Rating: IP67.
-
Overpressure: Relief plug opens at approximately 25 psig (1.72 bar), standard gages only. See Overpressure Protection note on Catalog page.
-
Temperature Limits: 20 to 140°F (-6.67 to 60°C). -20°F (-28°C) with low temperature option.
-
Size: 4" (101.6 mm) diameter dial face.
-
Mounting Orientation: Diaphragm in vertical position. Consult factory for other position orientations.
-
Process Connections: 1/8" female NPT duplicate high and low pressure taps - one pair side and one pair back.
-
Weight: 1 lb 2 oz (510 g); MP & HP 2 lb 2 oz (963 g).
-
Standard Accessories: Two 1/8" NPT plugs for duplicate pressure taps, two 1/8" pipe thread to rubber tubing adapters and three flush mounting adapterswith screws. (Mounting and snap ring retainer substituted for three adapters in MP & HP gage accessories.)
-
Agency Approval: Meets the technical requirements of EU Directive 2011/65/EU (RoHS II). Note: -SP models not RoHS approved.
Note: For applications with high cycle rate within gage total pressure rating, next higher rating is recommended. See Options Page.
