Purge meters are variable area flowmeters that used to measure small flowrates.
It is suitable for liquid, gas, oil and compressed air.
Ryutai Kogyo PGF-N series are calibrated to your operating temperature and pressure, as well as having scale range of your request.
It comes with stainless steel float and a metering a valve.
RCM Flo-Gard II Liquid Flow Switch – Adjustable Flow Alarm
:
RCM Flo-Gard II liquid flow switches detect when flow crosses a selected setpoint, providing a contact signal for an alarm or equipment interlock. Applications include cooling-water circuits, chillers and compatible process-liquid systems.
- Switch options: One or two independently adjustable SPDT reed switches.
- Construction: Metal body with material and seal options to suit the liquid.
- Local indication: Optional LEDs show switching status.
- Installation options: General-purpose and intrinsically safe configurations, subject to the required specification.
Monitor liquid flow at a selected operating threshold with the RCM Flo-Gard II flow switch. Its switching contacts can provide an input to an alarm, relay or equipment control circuit when flow rises or falls through the configured setpoint.
For a cooling-water or process-liquid installation, specify both the normal operating flow and the flow level at which action is required. This helps select an appropriate range and switch arrangement.
RCM Flo-Gard II reference illustration. Construction and options depend on the selected configuration.
Liquid flow monitoring applications
- Chillers and cooling circuits: Provide a flow-status input to the equipment controller.
- Heat exchangers: Signal when cooling-water flow crosses the required threshold.
- Liquid-cooled equipment: Monitor coolant circulation in machinery and packaged systems.
- Industrial utilities: Support flow alarms on compatible water, oil and process-liquid lines.
The switch provides the contact signal; the connected control system determines the alarm, shutdown or other response.
How the Flo-Gard II operates
A flow-induced differential pressure moves a bellows assembly. A magnet attached to the bellows actuates the reed switch as it passes the selected switching position.
SPDT contacts provide normally open and normally closed connections. Select the contact arrangement and control logic to suit the required response to increasing or decreasing flow.
Switch and indication options
| Option | Function | Selection guidance |
|---|---|---|
| 1S2 | One SPDT reed switch | For one switching threshold. |
| 2S2 | Two independently adjustable SPDT reed switches | For two thresholds, such as separate low-flow and high-flow signals. |
| LED | Visual switching-status indication | Useful when checking operation locally. Confirm the electrical requirements. |
| IS | Intrinsically safe configuration | Specify the hazardous-area classification and required approval when ordering. |
Operating and switching specifications
| Parameter | Specification / selection note |
|---|---|
| Standard maximum process temperature | 100°C; confirm compatibility with the selected seals and construction. |
| Maximum operating pressure | 400 psig, approximately 27.6 bar gauge. |
| Published minimum operating pressure | 10 psig, approximately 0.69 bar gauge. |
| Switch setability | ±5% of full scale. |
| Switch repeatability | ±1% of full scale. |
| Hysteresis | 13% of full scale for general-purpose versions; 7–13% for intrinsically safe versions. |
| Body and bellows options | Bronze or 316 stainless steel, depending on configuration. |
| Seal options | Buna-N, Viton, EPR or PTFE, subject to the selected specification. |
Understanding switch performance: Setability describes how closely the switching threshold can be adjusted. Repeatability describes consistency over repeated operation. Hysteresis is the separation between actuation and reset; these figures should not be treated as flow-reading accuracy.
Electrical connection
The general-purpose contacts are rated up to 10 W, 125 V AC or 175 V DC, with a maximum switching current of 350 mA. All applicable limits must be respected together; the maximum voltage and current cannot automatically be used simultaneously.
Use the contacts with a suitable control input or interface relay. Do not assume they can directly switch a pump motor or another high-power load.
Intrinsically safe versions have different electrical limits. Confirm the supplied unit’s certification, control drawing and associated circuit requirements before installation.
Request a flow switch quotation
Contact us for pricing and availability. Please include:
- Liquid name, composition and operating temperature.
- Pipe size and connection standard.
- Normal flow range and required switching setpoint.
- Operating pressure.
- One or two switches, and whether LED indication is required.
- Control-circuit voltage, load and any hazardous-area requirements.
- Quantity and existing model details, if replacing an installed unit.





























