Series-TFP-LI

Supported Applications

The Dwyer Series TFP-LI Liquid Turbine Flow Meters are designed for industrial, commercial, and laboratory flow applications involving clean liquids. These meters utilize a patented Pelton Turbine Wheel design with electro-optical detection to measure liquid flow rates as low as 0.13 LPM (0.21 GPH) up to 10 LPM (160 GPH). The series is suitable for recording and data logging where linear analog output signals are required.

Applications require liquids compatible with the wetted materials, which include PPS, acetal, sapphire, glass, epoxy, and fluoroelastomer. Units must be installed in clean environments; if the liquid contains particles larger than 25 microns, a filter of 25 microns or less should be installed upstream.

Operating Conditions & Performance

The Series TFP-LI 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 100 psig (6.8 bar).

Performance specifications include an accuracy of ±1% of full-scale and repeatability of ±0.2% of full-scale. Zero drift is minimized by the micro-turbine assembly design, which virtually floats in the liquid on sapphire bearings to eliminate wear under zero flow conditions.

The series provides a linear 0 to 5 VDC analog output signal with a minimum load resistance of 2.5 kΩ. A 3-1/2 digit LCD display indicates the actual flow rate in LPM (liters per minute). Pressure drop varies by percentage of rated flow, reaching up to 10 psid (0.7 bar) at 100% full scale.

Key Performance Parameters

• Accuracy: ±1% of full-scale
• Repeatability: ±0.2% of full-scale
• Process Temperature: 41 to 131°F (5 to 55°C)
• Storage Temperature: 32 to 158°F (0 to 70°C)
• Pressure Rating: 100 psig (6.8 bar)
• Output Signal: 0 to 5 VDC
• Load Resistance: Minimum 2.5 kΩ

Configuration Options

The Series TFP-LI is available in seven distinct models (TFP-LI03 through TFP-LI09), each configured for specific flow ranges and tubing connections. The meters feature a PPS body with an IP10 (NEMA 1) enclosure rating.

Model Selection by Flow Range

• TFP-LI03: .21 to 1.6 GPH (.013 to .1 LPM); 1/8" OD connection; Overall length (A) 3-27/64 in.
• TFP-LI04: .32 to 3.2 GPH (.02 to .2 LPM); 1/4" OD connection; Overall length (A) 3-13/16 in.
• TFP-LI05: .79 to 7.9 GPH (.05 to .5 LPM); 1/4" OD connection; Overall length (A) 3-13/16 in.
• TFP-LI06: 1.6 to 16 GPH (.01 to 1 LPM); 1/4" OD connection; Overall length (A) 3-13/16 in.
• TFP-LI07: 3.2 to 32 GPH (.2 to 2 LPM); 1/4" OD connection; Overall length (A) 3-13/16 in.
• TFP-LI08: 7.9 to 79 GPH (.5 to 5 LPM); 3/8" OD connection; Overall length (A) 4-1/8 in.
• TFP-LI09: 16 to 160 GPH (1 to 10 LPM); 3/8" OD connection; Overall length (A) 4-1/8 in.

Power and Accessories

A power adapter or mating cable assembly is required for operation but not included with the meter. The series supports a four-pin power and signal connector compatible with:

• A-454: 115 VAC Power Adapter and Signal Cable
• A-455: 230 VAC Power Adapter and Signal Cable
• A-456: 36" Mating Cable with Spliced Leads

The meters operate on a power supply of 11.5 to 15 VDC.

Key Product Differences

Variations within the Series TFP-LI are defined by flow range, process connection size (OD tubing), and overall physical length. Models TFP-LI04 through TFP-LI07 share a 1/4" OD compression fitting and an "A" dimension of 3-13/16 in., while models TFP-LI08 and TFP-LI09 utilize a larger 3/8" OD connection with an extended length of 4-1/8 in. The lowest range model, TFP-LI03, uses a 1/8" OD fitting.

All units feature the same black trim LCD display (1/4 in [6.35] opening) and trimpot adjustment access. While the manual references pulse outputs for the broader TF Series family, the specific TFP-LI data sheet documents only the 0 to 5 VDC analog output with integral LCD.

Caution is required regarding installation: units should not be subjected to strong magnetic fields or excessive vibration, and gas must never flow through these liquid sensors as it may damage the micro-turbine assembly. Every unit includes a calibration certificate based on deionized water; flowing liquids with different specific gravities or viscosities may affect calibration.