MKCM AIR SIGNAL flow switches combine a magnetic float and reed switch with a protective CAC902 cover. The standard acrylic tube allows local observation of float movement, while an electrical contact changes state at a specified factory-set gas-flow threshold. OFF and ON versions are listed separately for each port size.
Construction and operating specifications
| Parameter | Specification |
|---|---|
| Fluid | Gas; confirm the actual gas and reference conditions |
| Maximum temperature | 60°C |
| Pressure resistance | 1 MPa, standard version |
| Mounting orientation | Upward, downward or sideways; follow the intended flow direction |
| Standard connection | Rc female; R male or mixed arrangements on request |
| Maximum operating voltage | 300 V AC/DC |
| Maximum operating current | 0.5 A AC/DC |
| Contact capacity | 50 VA |
| Factory setting | Specify operating flow within the model range; not field-adjustable |
| Standard flow tube | Acrylic |
| Protective cover | CAC902 |
| Fittings | C3604 brass; SUS can be requested |
| Spring | SUS304 |
| Magnetic float | Acrylic or nylon; aluminum may be used for some specifications |
| Standard O-ring | Nitrile rubber |
| Reed switch | Magnetically operated contact |
| Standard lead length | 200 mm; other lengths or cabtyre cord on request |
| Heat-resistant option | Up to 100°C; brass tube and fluororubber seal |
| Pressure-resistant option | Up to 5 MPa; brass tube and fluororubber seal |
| Special-version visibility | Float cannot be observed through the brass tube |
Contact action and selection of operating flow
A magnetic float moves with gas flow and actuates a reed switch at the specified threshold. Select OFF when the contact should open as flow decreases, or ON when it should close as flow decreases. Keep the complete TA-OFF or TA-ON suffix in the order and wiring documentation. The threshold is set before shipment and cannot be adjusted later in the installation.
Factory setpoint range and line capacity
The operating-flow selection range is separate from the maximum flow through the assembly. The 20 body group allows a factory threshold of 1–40 L/min while listing 300 L/min maximum line flow; the 30 group lists 5–100 L/min and 600 L/min. The 35 group lists 30–150 L/min and 1,500 L/min, and the 45 group lists 50–300 L/min and 3,000 L/min. A maximum line-flow value must not be used as an available switch setpoint.
Complete models, dimensions and flow data
| Model | Port | Length (mm) | Width (mm) | Depth (mm) | Minimum bore (mm) | Factory setpoint selection range (L/min) | Maximum line flow (L/min) |
|---|---|---|---|---|---|---|---|
| MKCM20-1TA-OFF | Rc1/8 | 80 | 30 | 22 | 6.5 | 1 to 40 | 300 |
| MKCM20-1TA-ON | Rc1/8 | 80 | 30 | 22 | 6.5 | 1 to 40 | 300 |
| MKCM20-2TA-OFF | Rc1/4 | 80 | 30 | 22 | 6.5 | 1 to 40 | 300 |
| MKCM20-2TA-ON | Rc1/4 | 80 | 30 | 22 | 6.5 | 1 to 40 | 300 |
| MKCM20-3TA-OFF | Rc3/8 | 86 | 30 | 25 | 6.5 | 1 to 40 | 300 |
| MKCM20-3TA-ON | Rc3/8 | 86 | 30 | 25 | 6.5 | 1 to 40 | 300 |
| MKCM30-2TA-OFF | Rc1/4 | 100 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM30-2TA-ON | Rc1/4 | 100 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM30-3TA-OFF | Rc3/8 | 104 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM30-3TA-ON | Rc3/8 | 104 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM30-4TA-OFF | Rc1/2 | 110 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM30-4TA-ON | Rc1/2 | 110 | 44 | 32 | 9.5 | 5 to 100 | 600 |
| MKCM35-4TA-OFF | Rc1/2 | 124 | 49 | 44 | 13.5 | 30 to 150 | 1500 |
| MKCM35-4TA-ON | Rc1/2 | 124 | 49 | 44 | 13.5 | 30 to 150 | 1500 |
| MKCM35-6TA-OFF | Rc3/4 | 124 | 49 | 44 | 13.5 | 30 to 150 | 1500 |
| MKCM35-6TA-ON | Rc3/4 | 124 | 49 | 44 | 13.5 | 30 to 150 | 1500 |
| MKCM45-6TA-OFF | Rc3/4 | 142 | 62 | 50 | 18.0 | 50 to 300 | 3000 |
| MKCM45-6TA-ON | Rc3/4 | 142 | 62 | 50 | 18.0 | 50 to 300 | 3000 |
| MKCM45-8TA-OFF | Rc1 | 142 | 62 | 50 | 18.0 | 50 to 300 | 3000 |
| MKCM45-8TA-ON | Rc1 | 142 | 62 | 50 | 18.0 | 50 to 300 | 3000 |
Dimensions are in millimetres and the flow unit is retained as L/min. Select the complete gas-model designation, connection size and required installation envelope together. A matching thread size alone does not make different TA, TFA or TAR constructions interchangeable.
The protective cover is a casting, so overall dimensions at the casting surface can show individual variation. Check the detailed installation drawing and surrounding clearance before specifying a mounting arrangement.
Gas conditions and interpretation of flow data
Specify the gas, normal flow, operating pressure and temperature when selecting the device. Gas density depends on those conditions, so the pressure-resistance limit must not be treated as a flow-calibration reference pressure. The values here are reproduced in L/min without conversion to normal or standard litres per minute. Confirm the applicable reference conditions and unit basis for the intended installation before comparing them with another instrument or a normalized-flow requirement.
Electrical installation and special constructions
Observe the 300 V AC/DC, 0.5 A AC/DC and 50 VA contact limits together. The maximum voltage and current do not authorize a load above the contact-capacity limit. Protect the reed switch from overcurrent and wiring faults, and check the influence of nearby magnets or ferromagnetic parts. Alarm-detection duty is recommended wherever practicable, with the effect of a malfunction considered in the equipment design. Heat-resistant options up to 100°C and pressure-resistant options up to 5 MPa replace the transparent tube with C3604 brass and use fluororubber seals; their floats cannot be visually inspected. Confirm the selected option, operating threshold and lead arrangement.
Product and dimensional illustrations
Ordering information
Provide the complete model, gas type, normal flow and its unit basis, operating pressure and temperature, inlet and outlet connections, and available installation space. State OFF or ON contact action, the required switching flow within the permitted range, lead length and any special heat- or pressure-resistant version.