Flow Control
1020CZ125
Brooks Instrument GT1020 Variable-Area Flowmeter
About this part
Brooks Instrument 1020CZ125 identifies a configured GT1020 industrial variable-area flowmeter for visual gas or liquid flow measurement. The GT1020 uses a tapered borosilicate-glass metering tube and float within a protective housing. A documented unit bearing this identifier has horizontal 1/2-inch ANSI Class 150 flanged connections, a percent-of-maximum scale, and an alarm module; these are retained as observed configuration details because Brooks’ current GT1000 literature does not fully decode the compact legacy suffix CZ125
Configurations vary. Verify the exact unit before choosing a replacement.
No archived photo available
Key Facts
Specifications
| Manufacturer | Brooks Instrument |
| Product family | GT1000 Series |
| Model family | GT1020 |
| Measurement principle | Variable area; a float rises within a vertically installed tapered glass tube until fluid and gravitational forces reach equilibrium |
| Measured media | Gas or liquid |
| Standard flow accuracy | ±2% of full scale; Class 2.5 according to VDI/VDE |
| Optional flow accuracy | ±1% of full scale; Class 1.6 according to VDI/VDE |
| Repeatability | ≤0.5% of full scale |
| Ambient temperature | 33 to 125°F (1 to 52°C) |
| Metered-fluid temperature | 33 to 250°F (1 to 121°C) |
| Metering tube | Borosilicate glass |
| Window | Polycarbonate with ultraviolet inhibitor |
| Housing | Epoxy-painted cast aluminum |
| End-fitting options | Brass or 316/316L stainless steel |
| Seal options | Viton fluoroelastomer, Buna-N, Kalrez perfluoroelastomer, or EPDM; Kalrez and EPDM are limited to stainless-steel-body configurations |
| Connection options | NPT female, Rc/BSP threaded, or ANSI B16.5 Class 150 raised-face flange |
| Connection orientation | Horizontal or vertical inlet and outlet arrangements, according to base model |
| Scale construction | Single or dual detachable aluminum plate |
| Nominal scale lengths | 127, 200, or 250 mm |
| Scale formats | Direct-reading engineering units, millimeters, or percent of maximum flow with factor tag |
| Flow alarms | One or two adjustable alarm points; inductive sensors are used for meter sizes 2 and 6, while reed-switch alarms are offered for sizes 7 through 13 |
Identifier interpretation
The base model can be related to Brooks’ published GT1020 configuration, but the compact legacy suffix must remain intact unless the original order record or nameplate data are available.
GT1000 maximum pressure by meter size
Family-level maximum non-shock operating pressures at fluid temperatures through 250°F (121°C). The applicable row depends on the configured meter size and must not be selected from connection diameter alone.
| Meter size | NPT threaded maximum | ANSI Class 150 RF maximum | PED note |
|---|---|---|---|
| 2 | 500 psig (34.5 bar) | 240 psig (16.5 bar) | Sound Engineering Practice |
| 6 | 450 psig (31 bar) | 240 psig (16.5 bar) | Sound Engineering Practice |
| 7 | 300 psig (20.7 bar) | 240 psig (16.5 bar) | Sound Engineering Practice |
| 8 | 250 psig (17 bar) | 240 psig (16.5 bar) | Sound Engineering Practice |
| 9 | 200 psig (13.8 bar) | 200 psig (13.8 bar) | Sound Engineering Practice |
| 10 | 175 psig (12.1 bar) | 175 psig (12.1 bar) | Sound Engineering Practice |
| 12 | 100 psig (6.9 bar) | 100 psig (6.9 bar) | Not available for EU/EFTA use under the cited GT1000 documentation |
| 13 | 75 psig (5.2 bar) | 75 psig (5.2 bar) | Not available for EU/EFTA use under the cited GT1000 documentation |
Current retrofit path
Brooks positions the GT1600 Series as a configurable retrofit for GT1000 flowmeters. This is a family-level replacement path, not an exact successor assignment for 1020CZ125. A replacement must be configured to match the original tube and flow range, float, process-connection arrangement, connection size and type, seal material, scale, accuracy, alarm requirements, calibration conditions, and hazardous-location approvals.
Installation and safety notes
- Install the flowmeter with flow entering at the bottom and leaving at the top, within 5 degrees of true vertical.
- Open process valves slowly and avoid pressure or flow surges that can damage the glass tube.
- Do not operate above the pressure or temperature limit for the configured meter size and connection type.
- Secure the meter window before operation. The protective sleeve must remain over the glass tube on meter sizes 7 through 13.
- Confirm alignment between the tube reference mark and scale reference mark before operation and after reassembly.
- Use the complete GT1000 manual for alarm wiring and hazardous-location installation requirements.
Documentation Downloads
Local PDF copiesPart Photos
0 imagesHistorical archive images for identification, labels, connectors, and condition reference, not current inventory.
Historical Listings & Prices
Historical listing data, not a current offerRecorded price context is shown when available. Based on 0 archived listing records; not a current offer, appraisal, or confirmed sale price.
View archived listing titles
- Brooks Instruments GT1020 Industrial Glass Tube Variable Area Flowmeter W/Alarm