MKA AIR SIGNAL indicators use a cast-aluminum protective cover for visible gas-flow checking. The manufacturer describes more than 50% lower weight than the conventional MKC type. Ball or float movement shows that gas is passing through the tube; standard-flow figures support model selection without providing a calibrated numerical reading.
Construction and operating specifications
| Parameter | Specification |
|---|---|
| Fluid | Gas; confirm the actual gas and reference conditions |
| Maximum temperature | 80°C |
| Pressure resistance | 1 MPa, standard version |
| Mounting orientation | Upward, downward or sideways; follow the intended flow direction |
| Transparent tube | Acrylic |
| Fittings | C3604 brass |
| Spring | SUS304 |
| Ball | Nylon 66; cylindrical float may be used depending on specification |
| O-ring | Nitrile rubber |
| Protective cover | Cast aluminum |
| Standard connection | Rc female; R male or mixed arrangements on request |
| SUS fitting option | Available on request |
Flow-presence indication
Observe the ball or float to confirm that gas is moving through the transparent tube. The standard-flow values below guide selection, but this family does not supply a quantitative flow reading. A visible change in float position must not be converted into a calibrated L/min value. Where approximate flow indication is needed, assess the appropriate tapered-tube family; where numerical measurement or a remote alarm is required, specify that function separately.
Complete models, dimensions and flow data
| Model | Port | Length (mm) | Width (mm) | Depth (mm) | Standard minimum flow (L/min) | Standard maximum flow (L/min) |
|---|---|---|---|---|---|---|
| MKA0-1TA | Rc1/8 | 80 | 30 | 22 | 30 | 150 |
| MKA20-2TA | Rc1/4 | 80 | 30 | 22 | 30 | 150 |
| MKA20-3TA | Rc3/8 | 86 | 30 | 22 | 30 | 150 |
| MKA30-2TA | Rc1/4 | 100 | 44 | 32 | 60 | 300 |
| MKA30-3TA | Rc3/8 | 104 | 44 | 32 | 60 | 300 |
| MKA30-4TA | Rc1/2 | 110 | 44 | 32 | 60 | 300 |
| MKA35-4TA | Rc1/2 | 124 | 49 | 44 | 100 | 1000 |
| MKA35-6TA | Rc3/4 | 124 | 49 | 44 | 100 | 1000 |
| MKA45-6TA | Rc3/4 | 142 | 62 | 50 | 200 | 1000 |
| MKA45-8TA | Rc1 | 142 | 62 | 50 | 200 | 1000 |
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.
Smallest-model designation
The 1/8-inch model is printed as MKA0-1TA in both the English and Japanese product tables. That designation is retained in the table above. Confirm the complete order code with the supplier when selecting this smallest 80 × 30 × 22 mm configuration; do not silently substitute an inferred model number. The remaining listed models retain their MKA20, MKA30, MKA35 and MKA45 designations.
Alternative threaded ordering examples
| Published alternative connection example | Arrangement |
|---|---|
| MKA20-3TOA | R male at both ends |
| MKA20-3TOMA | R male inlet |
| MKA20-3TMOA | R male outlet |
These codes are examples of alternative threaded arrangements. Confirm the installed dimensions and availability of the requested fitting configuration rather than transferring the standard model dimensions automatically.
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.
Materials and installation checks
The standard assembly uses an acrylic tube, C3604 brass fittings, SUS304 spring, Nylon 66 ball and nitrile-rubber O-ring; a cylindrical float may be used for some specifications. Match the materials to the actual gas and service conditions. The spring-supported design permits upward, downward or sideways mounting, while the inlet and outlet must still follow the intended flow direction. Keep the tube accessible for observation. Check the fittings and tube for leakage or damage during commissioning. The standard maximum temperature is 80°C and pressure resistance is 1 MPa.
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 any nonstandard flow requirement for a specific selection, and confirm the fitting material and connection arrangement. Retain the complete internal-selection suffix when choosing the TA, TFA or TAR form.