Series-DR

Supported Applications

The Dwyer Series DR Direct Reading Glass Flowmeters are designed for the direct flow measurement of air, water, and other commonly used gases. These variable area flow meters feature direct read scales that eliminate the need for correlation charts in standard applications.

Operating Conditions & Performance

The series operates within a process temperature limit of 250°F (121°C) and a pressure rating of 250 psig (17 bar). Accuracy is specified as ±5% FS @ 70°F (21.1°C) and 14.7 psia (1 atm absolute), with repeatability of ±0.25% of scale reading. The meters provide a turn-down ratio of 10:1.

Measurement ranges vary by model configuration:

• Air in 65 mm scales: Ranges from 0.24 SCFM (130 SCCM) to 2.2 SCFM (1000 SCCM), and 5.6 L/min (2.1 LPM) to 100 L/min (50 LPM).
• Water in 65 mm scales: Ranges from 0.02 GPH (1.5 SCCM) to 24 GPH (1500 SCCM).
• Air in 150 mm scales: Ranges from 0.33 SCFM (160 SCCM) to 2 SCFM (840 SCCM), and 3.8 L/min (1.8 LPM) to 90 L/min (44 LPM).
• Water in 150 mm scales: Ranges from 0.05 GPH (3.2 SCCM) to 21 GPH (1300 SCCM).

The series requires vertical mounting and utilizes a standard connection of 1/8" female NPT.

Configuration Options

The Series DR is available in two primary scale sizes: 65 mm and 150 mm. Models are offered with or without an integrated valve; models equipped with a valve include a standard 6-turn needle valve.

• Housing Materials: Aluminum (anodized) or 316 SS end fittings.
• Wetted Parts: Borosilicate glass flowtube; Floats are available in 316 SS or black glass as indicated by the model number. Float stops utilize PTFE material.
• O-rings: Buna-N on aluminum models and fluor elastomer on stainless steel (SS) models.

NIST traceable calibration certificates are available as options: NISTCAL-FL1 for variable area air flowmeters and NISTCAL-FL2 for variable area water flowmeters. Metric scales can be specified by adding the suffix "M" to the model number, though some specific models (e.g., DR200682) are noted as not available in metric scale.

Key Product Differences

The series distinguishes between aluminum and stainless steel construction via the model numbering system. Models without a valve follow one pattern, while those with an integrated 6-turn needle valve follow another (e.g., DR104xx vs. DR100xx). The float material is indicated by specific digits within the part number; glass floats are denoted in documentation notes.

Dimensional differences exist between scale sizes:

• 65 mm models: Height 4-1/2" [114.3], Length 5-1/2" [139.7].
• 150 mm models: Height 8-13/16" [223.84], Length 9-13/16" [249.24].