Series-TFM-LP

Supported Applications

The Dwyer Series TFM-LP Liquid Turbine Flow Meters are designed for industrial, commercial, and laboratory flow applications involving clean liquids. These meters utilize a turbine wheel with electro-optical detection to convert liquid flow rates into linear output signals suitable for recording and data logging. The series is compatible with the Series TM2 Flow Totalizer for remote monitoring displays.

Media compatibility requires that all wetted parts be checked against the specific liquid in use; highly corrosive liquids may damage the unit or void the warranty. A filter of 25 microns or less should be installed upstream if the liquid contains particles larger than this size. Gas flow is prohibited as it may damage the micro-turbine assembly.

Operating Conditions & Performance

The Series TFM-LP operates within a process temperature range of 41 to 131°F (5 to 55°C) and supports storage temperatures from 32 to 158°F (0 to 70°C). The meters are rated for pressures up to 500 psig (34.5 bar).

Performance specifications include an accuracy of ±1% of full-scale and repeatability of ±0.2% of full-scale. Units feature a patented Pelton Turbine Wheel design that minimizes zero drift, as no pulses are generated under zero flow conditions. The series offers measurement ranges spanning from 0.21 to 160 GPH (0.13 to 10 LPM) depending on the specific model selected.

Pressure drop varies with flow percentage; at 10% of rated flow, pressure drop is 0 psid/Bar, increasing to 10 psid (0.7 Bar) at 100% of full scale rated flow (values may vary ±10%).

Configuration Options

The series provides configurable options for output signals, power supply connections, and process fittings tailored to specific installation needs.

• Output Signals: 0 to 5 VDC analog (minimum load resistance 2.5 kΩ) or Pulse outputs (7.5 VDC peak buffered square wave).
• Housing and Materials: The body is constructed of 316SS with an IP10 (NEMA 1) enclosure rating. Wetted materials include 316 SS, acetal, sapphire, glass, epoxy, and fluoroelastomer.
• Process Connections: Compression fittings vary by model: TFM-LP03 uses 1/8" OD; models TFM-LP04 through TFM-LP07 use 1/4" OD; models TFM-LP08 and TFM-LP09 use 3/8" OD.
• Electrical Connections: A four-pin power and signal connector is standard. Operation requires a separate power adapter or mating cable assembly (e.g., A-454 for 115 VAC, A-455 for 230 VAC, or A-456 with spliced leads).
• Power Supply: Requires 11.5 to 15 VDC.

Key Product Differences

The Series TFM-LP is available in multiple models (TFM-LP03 through TFM-LP09), each defined by a specific flow range and physical dimension "A". The overall length varies from 3-27/64 inches for the smallest model to 4-1/8 inch for larger capacity units.

Model-specific ranges include:

• TFM-LP03: 0.21 to 1.6 GPH (0.13 to 1 LPM)
• TFM-LP04: 0.32 to 3.2 GPH (0.2 to 0.2 LPM) — Note: Source text lists upper limit as 0.2 LPM for this model.
• TFM-LP05: 0.79 to 7.9 GPH (0.5 to 5 LPM)
• TFM-LP06: 1.6 to 16 GPH (0.1 to 1 LPM) — Note: Source text lists lower limit as 0.1 LPM for this model.
• TFM-LP07: 3.2 to 32 GPH (2 to 2 LPM)
• TFM-LP08: 7.9 to 79 GPH (5 to 5 LPM)
• TFM-LP09: 16 to 160 GPH (1 to 10 LPM) — Note: Source text lists lower limit as 1 LPM for this model.