OPERATING PRINCIPLE

The HEDLAND Flow Meter is a variable area type flow meter, using a sharp-edged annular orifice, formed between the piston (4) and the tapered metering cone (3). The piston assembly, containing a permanent ring magnet, is held in a no flow* position, at the base of the cone, by a calibrated retention spring (6).

Flow through the meter creates a pressure differential across the piston orifice, moving the piston against the retaining spring. Piston movement and orifice area are proportional to the rate of flow. Therefore, the greater the rate of flow, the further the piston moves along the tapered metering cone.

Externally, the flow indicator ring (5) encircling the rugged flow meter body (2) is magnetically coupled to the high flux density magnet, mounted in the piston assembly (4). The orange line on the indicator ring is simply read against the pre-calibrated scale (7), mounted on the inner surface of the transparent Lexan dust guard.

*The Hedland Flow Meter is not bidirectional. The piston acts as a check valve to block flow in reverse direction.

RUGGED CONSTRUCTION

Offered in a variety of construction materials, including; anodized aluminum, brass, stainless steel and high impact resistant polysulfone, this simple variable-area flow meter performs as a reliable, relatively trouble-free flow rate indicator, monitoring a wide range of liquids and gases (including aggressive chemicals), under various pressures, temperatures and other rigorous conditions frequently required in industrial class applications.

OPERATES IN ANY POSITION

The HEDLAND In-line Flow Meter is simple (and less costly) to install. It can be installed directly into horizontal or vertical lines or, with an optional inverted flow scale, this flow meter can monitor flow in a downward (i.e. gravity-feed) line.

ACCURACY WITHIN ± 4%

NO FLOW STRAIGHTENERS OR SPECIAL PIPING

Thiscompactflow meter does not require any flow straighteners, or special lengths of straight inlet piping to stabilize turbulent flow patterns. It can be installed immediately adjacent to a right angle elbow or other piping fixture, giving you greater system design flexibility, as well as saving time and money during installation.

RELATIVELY INSENSITIVE TO SHOCK AND VIBRATION

This piston-type variable-area design is inherently less sensitive to shock and vibration than other variable-area designs. The unique magnetic coupling also eliminates the need for mechanical linkages that can wear or loosen over the functional life of the meter.

GOOD VISCOSITY STABILITY

The piston's sharp-edged orifice also assures greater operating stability and accuracy over a wide range of viscosities.

In a 3" meter, a tripling of viscosity (44-130 SSU) produces no measurable change in reading. The 1/4" meter (the most viscosity sensitive), produces a 1.5% change in the reading over the same range.

Consult factory for further details on viscosities over 200 SSU.

DIRECT READING

The linear movement of the flow indicator ring (traversing the outer surface of the fl low meter body) provides a quick direct visual reading, against the vertically graduated flow scale (mounted on the inner surface of the transparent dust cover), eliminating the need for further calculations or corrections.

The standard flow scale, for fluids, is calibrated in GPM and LPM, at 1.0 specific gravity for water and water-based fluids, or at .876 specific gravity for oil and petroleum-based fluids. Special scales are available in other units of measurement or specific gravities.

The pneumatic flow meter is offered with a unique multi-pressure flow scale, calibrated to indicate flow rate, in standard cubic feet per minute (SCFM) at various pressures from 40 to 130 PSI. See "Pneumatic Flow Meter" section for further details.

NO ELECTRICAL CONNECTIONS