Flow Control
1024CH21C91AA
Brooks Instrument Glass-Tube Variable-Area Flowmeter
About this part
1024CH21C91AA is a configured Brooks Instrument model 1024 industrial glass-tube variable-area flowmeter. Brooks documentation identifies the 1024 form as the vertical-inlet, vertical-outlet member of the GT1000 family. Stored photographs verify one exact unit's serial and 450-psig-at-250 °F nameplate limit, plus an SCFM gas data tag; glare prevents a reliable full-scale reading. The legacy suffix is not equivalent to the current 1024N ordering-code format, so calibration and material details still require the unit's original records
Configurations vary. Verify the exact unit before choosing a replacement.
Key Facts
Specifications
| Manufacturer | Brooks Instrument, LLC |
| Model/configuration identifier | 1024CH21C91AA |
| Product family | GT1000 industrial glass-tube variable-area flowmeters |
| Connection orientation | Vertical inlet and vertical outlet; established by the Brooks 1024 base-model designation |
| Measuring principle | Mechanical variable-area indication using a float in a tapered glass tube |
| Supported media | Gas or liquid; the exact unit is calibrated and scaled for a specific application |
| Basic indication | Local visual flow indication; no electrical power is required for the basic meter |
| Accuracy options | GT1000 family: standard ±2% of full scale, Class 2.5 per VDI/VDE; optional ±1% of full scale, Class 1.6 per VDI/VDE. Exact unit option is unresolved |
| Repeatability | GT1000 family: ≤0.5% of full scale |
| Scale construction and lengths | GT1000 family options: single or dual detachable aluminum scale; nominal lengths 127, 200 or 250 mm; direct-reading, millimeter or percent graduations. Exact unit selection is unresolved |
| Ambient temperature | GT1000 family: 33 to 125 °F (1 to 52 °C) |
| Process-fluid temperature | GT1000 family meter limit: 33 to 250 °F (1 to 121 °C), subject to the configured materials and accessories |
| Metering tube | Borosilicate glass |
| Housing and window | GT1000 family: epoxy-painted cast-aluminum housing with a UV-inhibited polycarbonate window |
| End-fitting options | GT1000 family: brass or 316/316L stainless steel; exact unit material is unresolved |
| Seal options | GT1000 family: Viton fluoroelastomer, Buna-N, Kalrez perfluoroelastomer or EPDM, with availability dependent on body material; exact unit material is unresolved |
| Process-connection options | GT1000 family: female NPT or Rc/BSPT threaded connections, or ANSI Class 150 raised-face flanges on stainless-steel fittings; exact unit type and size are unresolved |
| Required alignment | Mount with the inlet at the bottom and within 6 degrees of true vertical |
Identifier interpretation and configuration boundary
The base model can be interpreted from Brooks documentation, but the remaining characters cannot safely be decoded with the current ordering table.
GT1000 maximum operating pressure by meter size
Brooks’s family table gives maximum non-shock pressure at fluid temperatures up to 250 °F (121 °C). The meter size encoded in this legacy identifier has not been established, so these ratings must not be assigned to the exact unit without nameplate or tube verification. Sizes 12 and 13 also carry special PED restrictions in the 2018 literature.
| Meter size | NPT threaded connection | ANSI Class 150 RF flange |
|---|---|---|
| 2 | 500 psig / 34.5 bar | 240 psig / 16.5 bar |
| 6 | 450 psig / 31 bar | 240 psig / 16.5 bar |
| 7 | 300 psig / 20.7 bar | 240 psig / 16.5 bar |
| 8 | 250 psig / 17 bar | 240 psig / 16.5 bar |
| 9 | 200 psig / 13.8 bar | 200 psig / 13.8 bar |
| 10 | 175 psig / 12.1 bar | 175 psig / 12.1 bar |
| 12 | 100 psig / 6.9 bar | 100 psig / 6.9 bar |
| 13 | 75 psig / 5.2 bar | 75 psig / 5.2 bar |
Safety and installation notes
The glass measuring tube is pressure-containing equipment and requires controlled startup and complete depressurization before service.
- Keep the meter within the specified vertical alignment, with flow entering at the bottom.
- Open process valves slowly and avoid pressure or flow surges.
- Do not exceed the configured pressure or temperature limits and do not service the meter while pressurized.
- For meter sizes 7 through 13, the protective sleeve must remain over the glass tube and the meter windows must be secured.
- A liquid-filled meter isolated by closed inlet and outlet valves must be drained to prevent rupture from thermal expansion.
- Verify scale alignment after initial installation and whenever the flowmeter is reassembled.
Replacement relationship
Brooks positions the GT1600 series as the current configurable replacement platform for GT1000 installations. Replacement selection is configuration-dependent rather than a universal substitution.
Documentation Downloads
Local PDF copiesPart Photos
5 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 $149.99 to $149.99. Based on 1 archived listing record; not a current offer, appraisal, or confirmed sale price.
View archived listing titles
- BROOKS INSTRUMENTS 1024CH21C91AA VARIABLE AREA FLOW METER