FLD-Water-Series

Supported Applications

The Omega FLD Series comprises direct read variable area flow meters (rotameters) designed for the measurement of water and various gases. The series is engineered for applications including metering carrier gases in chromatography, indicating and controlling gases in manufacturing processes, liquid and gas measurement in laboratories and pilot plants, as well as general flow and level indication.

Operating Conditions & Performance

The FLD Series operates with a standard accuracy of plus/minus 5% of full scale (FS) and repeatability of plus/minus 0.25%. The useful flow range is specified as a minimum ratio of 10:1, where the minimum flow rate is 10% of the maximum rate shown for each model.

Performance limits are defined by a maximum operating pressure of 200 psig/13.8 bars and a maximum operating temperature of 121 C (250 F). The series supports water measurement ranges from 0.5 to 750 mL/min for the 65 mm tube size, and includes configurations covering 1 to 500 mL/min, 1.2 to 2 L/min, 3 L/hr, 29 gph, and 0.22 to 0.45 gpm for the 150 mm tube size.

Configuration Options

The series offers configurable dimensions across two primary tube lengths: 65 mm and 150 mm. Frames are available in aluminum (black anodized) or 316 stainless steel, with flow tubes constructed from heavy walled borosilicate glass.

Float Materials

Interchangeable floats are offered in the following materials:

• Glass (suffix G)
• 316 Stainless Steel (suffix ST)
• Carboloy (suffix C)
• Red Sapphire (suffix SA)

Housing and Mounting

The standard configuration features a polycarbonate resin front shield with a longitudinal magnifier lens for enhanced reading resolution, aluminum side panels, and a 1/8 in thick white acrylic back plate. Units are designed for panel mounting (drill two 15 mm holes; maximum panel thickness 9.5 mm) or bench mounting using optional FLTR-1, FLTR-2, or FLTR-3 acrylic tripods with built-in spirit levelers.

Valve and Connection Options

Inlet and outlet connections are standard at 1/8 NPT female. Valve configurations include:

• Built-in 6-turn needle valves (standard)
• -HRV suffix: 16 turn high resolution non-rising stem valve for 150 mm meters
• -NV suffix: Unit without valve

Valve position is standard at inlets (bottom); for liquids, valves may be located at inlets or outlets (top). For vacuum services, valves must be mounted at outlets. O-rings and packing include Buna for aluminum/brass models and FKM for stainless steel meters; perfluoroelastomer and EPR are optional.

Key Product Differences

The series is organized by fluid type (e.g., FLDA Air, FLDW Water) and tube length. Model numbers follow the pattern FLD[fluid letters][4-digit tube/size/range number][float suffix][options]. For example, models such as FLDW3201S denote a 65 mm water meter with an aluminum frame and glass float, while FLDW3501C indicates a 150 mm unit with a stainless steel frame and carboloy float. Specific flow ranges are tied to the model number suffixes defined in the ordering tables.