Flow Control
L-478
Brooks Instrument 1250AR6091MRAVB Sho-Rate Variable-Area Flow Meter — Archive Identifier
About this part
Brooks Instrument L-478 is a configured flow meter for industrial automation and process equipment.
Configurations vary. Verify the exact unit before choosing a replacement.
Key Facts
Specifications
| Manufacturer | Brooks Instrument |
| Product line | Sho-Rate 1250 Series |
| Observed manufacturer configuration code | 1250AR6091MRAVB |
| Base model | 1250A |
| Measuring principle | Variable area, using a tapered borosilicate-glass metering tube and float |
| Scale length | 65 mm |
| Tube number | R6091 |
| Scale | Millimeter reference scale with standard data tables |
| Float | Glass ball, 1/4-inch diameter |
| Wetted end blocks and connections | Aluminum, 1/8-inch FNPT |
| Valve | Standard inlet cartridge valve |
| Valve material | Brass, as specified for aluminum end blocks |
| Valve O-ring | Buna |
| Model 1250 accuracy | ±5% of full scale at reference conditions for listed gases |
| Repeatability | 0.25% of full scale |
| Published reference conditions | 70°F (21.1°C) and 14.7 psia (1 bar absolute) |
| Maximum pressure | 200 psig (13.8 bar) |
| Conservative maximum temperature | 200°F (93°C), following the installation manual's explicit operating caution |
| Supported arrangements | Panel mounting or optional leveling tripod base |
What Does L-478 Mean?
L-478 is not a segment of the Brooks ordering code. The manufacturer identity associated with this archive record is the complete observed code 1250AR6091MRAVB.
| Segment | Field | Interpretation |
|---|---|---|
| L-478 | Identifier boundary | Archive or secondary identifier; no official Brooks model-code meaning is documented |
| 1250A | Base model | 65 mm tube flow meter |
| R6091 | Tube number | R6091 metering tube |
| M | Gas or liquid field | Millimeter reference scale with standard data tables |
| R | Unit of measure | Millimeter |
| A | Wetted end blocks | Aluminum with 1/8-inch FNPT connections |
| V | Valve designation | Standard inlet valve |
| B | Valve O-ring | Buna; documented for aluminum configurations |
R6091 Reference Capacity
The Brooks capacity table associates R6091 with a glass float and publishes air and water reference capacities. These values do not establish the archived meter's process fluid or calibrated range.
| Tube | Float | Float diameter | Air reference capacity | Water reference capacity |
|---|---|---|---|---|
| R6091 | Glass | 1/4 inch | 15,750 ccm | 375 ccm |
Millimeter-Scale Use
A millimeter indication is not a direct universal flow reading. Use the flow-curve document supplied for the configured tube.
Safety and Service Notes
Observe the restrictions for a pressurized glass-tube meter.
- Use only with compatible, non-hazardous fluids.
- Do not use toxic fluids or fluids that react with glass, including steam, alkalis, fluorine, hydrofluoric acid, molten metal, or water above 140°F (60°C).
- Select process-compatible aluminum, brass, Buna, glass, and other wetted materials before installation.
- Introduce flow and pressure slowly, check for leakage, and protect the meter from pressure or flow surges.
- Completely drain liquid before closing adjacent inlet and outlet valves to prevent rupture from thermal expansion.
Documentation Downloads
Local PDF copiesPart Photos
2 imagesHistorical archive images for identification, labels, connectors, and condition reference, not current inventory.
Historical Listings & Prices
Historical listing data, not a current offerThe typical recorded price range is $320.00 to $320.00. Based on 1 archived listing record; not a current offer, appraisal, or confirmed sale price.
View archived listing titles
- BROOKS INSTRUMENT 1250AR6091MRAVB SHO-RATE GLASS TUBE FLOW MASTER L-478