Sensors and Gauges
3602
Brooks (MT3602) Metal-Tube Variable-Area Flowmeter
About this part
The Brooks 3602, identified in later manufacturer literature as the MT3602, is a legacy armored metal-tube variable-area flowmeter with female NPT process connections and a vertical-inlet, horizontal-outlet geometry. Flow moves a tapered plug in a fixed orifice; an external follower is magnetically coupled to the plug for local indication without external power. Connection size, capacity, scale, seal, indicator, alarm, and accessory selections are configuration-dependent and must be established from the complete suffix and instrument nameplate
Configurations vary. Verify the exact unit before choosing a replacement.
Key Facts
Specifications
| Manufacturer | Brooks Instrument |
| Model | 3602; identified as MT3602 in later Brooks literature |
| Series | MT3600 / MT36xx Series |
| Product status | Legacy and obsolete |
| Measuring principle | Metal-tube variable-area flow measurement using a tapered plug in a fixed orifice |
| Indication | External tubular follower magnetically coupled to the metering plug |
| Media | Liquids and gases; gas service is limited to the 1/2-inch size |
| Standard accuracy | ±10% of full scale from 100% to 10% of scale |
| Optional accuracy | ±5% of full scale |
| Repeatability | 1.0% of full scale |
| Process connection | Female NPT threaded |
| Available connection sizes | 1/2 inch, 1 inch, and 1-1/2 inches |
| Connection orientation | Vertical inlet and horizontal outlet |
| Maximum threaded pressure | Up to 1,500 psig (100 bar) at 200°F (93.3°C); allowable pressure depends on temperature and configuration |
| Fluid-temperature envelope | −20°F to 500°F (−29°C to 260°C); 500°F requires the all-welded configuration, while seal and alarm options impose lower maxima |
| Ambient-temperature range | −20°F to 122°F (−29°C to 50°C) |
| Wetted construction | 316 stainless steel |
| Indicator housing | Clear-anodized aluminum with glass window standard; polished 316 stainless steel housing optional |
| Seal options | Fluoroelastomer standard; silicone, Buna-N, Kalrez, EPR, PTFE, metal, and all-welded constructions were configuration-dependent options |
| Control valve or flow controller | Available on the 1/2-inch Model 3602 in 316 stainless steel, mounted at the inlet or outlet |
| Approximate shipping weight | 5 lb (2.26 kg) for 1/2 inch; 7 lb (3.17 kg) for 1 inch; 12 lb (5.44 kg) for 1-1/2 inches |
Standard capacity selections
Brooks listed the following standard air and water full-scale capacities. These are ordering selections, not a single universal range for every Model 3602.
| Connection size | Standard air full-scale selections | Standard water full-scale selections | Service limitation |
|---|---|---|---|
| 1/2-inch female NPT | 23, 58, 120, 195, 425, 790, or 1,660 SCFH | 5, 15, 30, 50, 100, 180, or 300 GPH | Air values are referenced to 14.7 psia and 70°F; gas service requires at least 35 psig downstream pressure. |
| 1-inch female NPT | Not offered | 5, 10, or 15 GPM | Not available for gas service because of float stability. |
| 1-1/2-inch female NPT | Not offered | 20, 30, 40, or 50 GPM | Not available for gas service because of float stability. |
Configuration boundary
The base identifier 3602 does not establish one flow range or complete construction. Brooks documentation shows selectable connection size, capacity, body and float material, indicator or alarm arrangement, scale and accuracy, seal material, and accessories. Later documentation uses a 3602B-based ordering code, while surviving instruments also carry older hyphenated codes such as 3602-08A2A1C. A legacy suffix should not be translated through the later code table without the instrument nameplate, calibrated scale, or original order record.
Installation and operating essentials
- Install with the inlet at the bottom and the outlet perpendicular to the inlet.
- Align the meter within five degrees of true vertical to preserve its stated accuracy.
- Initiate flow slowly and open process valves gradually to avoid a damaging flow surge.
- Remove process pressure before servicing; Brooks warns that retained high pressure can cause serious injury or equipment damage.
Legacy replacement guidance
Brooks classifies the MT3601 and MT3602 as obsolete and offers a special-order retrofit path rather than one universal catalog replacement.
Documentation Downloads
Local PDF copiesPart Photos
44 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 $65.47 to $416.93. Based on 26 archived listing records; not a current offer, appraisal, or confirmed sale price.
View archived listing titles
- BROOKS WATER FLOW INDICATOR METER GAUGE MODEL 3602 GPH