Series-WM2-WMT2

Supported Applications

The Dwyer Series WM2 and WMT2 Multi-Jet Water Meters are mechanical totalizing flow meters designed for commercial and industrial applications. The product overview identifies specific uses including irrigation, cooling systems, filtration systems, and general water monitoring. These units measure water flow with a multi-jet design intended to provide accuracy across wide flow ranges, even in low-flow conditions.

Operating Conditions & Performance

The series is rated for a maximum process temperature of 104°F (40°C) and a pressure rating of 232 psi (16 bar). Accuracy specifications are defined by flow regime: ±5% at Transitional Flow and ±2% at Nominal Flow. The meters feature an internal strainer to protect the measuring mechanism.

Measurement ranges vary by model size, covering:

• GPM (Gallons Per Minute): 1 to 20 GPM, 2 to 30 GPM, 3 to 50 GPM, 5 to 100 GPM, and 8 to 160 GPM.
• m³/h: 0.12 to 1.5 m³/h, 0.2 to 2.5 m³/h, 0.28 to 3.5 m³/h, 0.48 to 6 m³/h, 0.8 to 10 m³/h, and 1.2 to 15 m³/h.

Installation requires a horizontal orientation with the register face pointing up; deviation from this position may cause leakage or meter damage. The tap height should be higher than the meter for accurate measurement.

Configuration Options

The series encompasses two primary configurations: mechanical totalizers (WM2) and pulsed-output models (WMT2). Both share common physical dimensions, wetted materials, and pressure/temperature limits but differ in output functionality.

• Series WM2: Features a magnetically driven, hermetically sealed register that displays total water usage. The display is completely separated from the water to prevent leaking or fogging. Display maximums range up to 9,999,999.99 Gallons or equivalent m³ values depending on the model.
• Series WMT2: Includes a pulse output with frequency proportional to flow rate generated by a reed switch. Pulse options are available at rates of 0.1 gal/pulse, 1 gal/pulse, 10 gal/pulse, and 100 gal/pulse (or 1 L, 10 L, 100 L per pulse). These models require an external power supply rated at 0.01 A @ 24 VAC/DC.

Process Connections:

• A Series (NPT): Available with NPSM couplings ranging from 1/2" to 2-1/2" Spud sizes, corresponding to meter body sizes of 5/8" through 2".
• B Series (BSPT): Available with BSPP couplings for metric pipe sizes including 15 mm, 20 mm, 25 mm, 32 mm, 40 mm, and 50 mm.

Wetted Materials:

• Body: Brass, polyethylene
• Couplings: Brass
• Measuring Chamber: Polyethylene, ABS plastic, ferrite, acetal

Key Product Differences

The primary distinction between the two series is the presence of an electrical output. The WM2 models provide a mechanical totalizing display only. The WMT2 models add color-coded lead wires (4.5' / 1.5 m long) and require external power to generate pulse signals.

Model selection varies by coupling type, size, and for the WMT2 series, by pulse rate configuration. Specific model numbers in the A Series with a "*" designation indicate that an inlet filter is not included. Display maximums differ between GPM-based models (up to 9,999,999.99 Gallons) and m³/h-based models (values such as 99,999,9999 or 999,999,9999 depending on the specific model row).

Dimensions scale with size; for example, a Size 5/8" unit has an overall length of 6-1/2 (165) mm and weighs 3.75 lb (1.7 kg), while a Size 2" unit measures 11-13/16 (300) mm in length and weighs 18.74 lb (8.5 kg). The series is not field serviceable; units requiring repair must be returned to the manufacturer.