Brooks Model 1305 Glass-Tube Variable-Area Flowmeter
About this part
Brooks 1305EJ1BCJ2BA is a threaded, size-8 Model 1305 variable-area flowmeter. Its documented corresponding configuration uses an R-8M-75-1 borosilicate-glass metering tube, an 8-RJ-39 stainless-steel float, and an on-tube GPM scale for water at specific gravity 1.0 and viscosity 1.0 cP. The material code specifies 316 stainless-steel fittings, Viton O-rings, and aluminum side plates. This configuration has a 5 GPM full-scale water capacity, 1/2-inch female NPT vertical connections, and no accessory
Configurations vary. Verify the exact unit before choosing a replacement.
ManufacturerBrooks Instrument Model 1305 / GT130x Series
Part number1305EJ1BCJ2BA
Product familyConfiguration-specific
Device typeFlowmeter
Configuration statusConfiguration varies
Application classIndustrial automation and process equipment
CategoryFlow Control
Specifications
Identification
Manufacturer
Brooks Instrument; legacy records identify Emerson Electric Co., Brooks Instrument Division
Product family
Model 1305, GT130x Series
Measurement principle
Variable area, free-float indication
Construction
Single glass metering tube in a bolted side-plate housing
Configured Flow Range
Full-scale water capacity
5.00 GPM
Reference fluid
Water, specific gravity 1.0 and viscosity 1.0 cP
Scale
Direct-reading GPM scale printed on the tube
Pressure drop at full-scale flow
34 inches water column
Configured Metering Elements
Meter size
Size 8
Metering tube
R-8M-75-1
Float
8-RJ-39, 316 stainless steel
Performance
Standard flow accuracy
±10% of full scale from 100% to 10% of scale reading
Repeatability
1% of full scale
Scale length
75 mm (3 inches)
Process Connections
Connection type and size
1/2-inch female NPT inlet and outlet
Connection orientation
Vertical; inlet at bottom and outlet at top
Materials
Metering tube
Borosilicate glass
Fittings
316 stainless steel
O-rings
Viton fluoroelastomer
Side plates
Aluminum
Protective tube sleeve
UV-stabilized polycarbonate
Window
Scratch-resistant, UV-stabilized polycarbonate
Bolts
300-series stainless steel
Ratings
Maximum operating pressure
200 psig (13.8 bar)
Maximum compatible-fluid temperature
250°F (121°C); fluid-compatibility restrictions still apply
Ambient temperature range
33 to 125°F (1 to 52°C)
PED category
SEP
Dimensions
Overall height
7.75 inches (196.85 mm)
Width
2.375 inches (60.33 mm)
Depth
2.375 inches (60.33 mm)
Nominal weight
3.8 lb (1.7 kg) for stainless-steel construction
Accessories
Factory accessory code
A — none
What Does 1305EJ1BCJ2BA Mean?
The legacy 1305E base is decoded through Brooks' documented 1305F configuration table and the stock-item cross-reference that associates both complete identifiers with the same item.
Segment
Field
Interpretation
1305E
Base model
Legacy threaded Brooks Model 1305. Later Brooks documentation uses the 1305F base for the corresponding configuration.
J1
Tube designator
Size-8 R-8M-75-1 metering tube; 75 mm scale and 1/2-inch female NPT connections.
BC
Float designator
8-RJ-39 float; the Brooks capacity table assigns this float a 5.00 GPM water capacity and 34-inch-water-column pressure drop.
J2
Scale
On-tube GPM scale for water at specific gravity 1.0 and viscosity 1.0 cP.
B
Materials of construction
316 stainless-steel fittings, Viton O-rings, and aluminum side plates.
A
Accessory
No accessory.
Replacement and Cross-Reference Boundaries
Cross-references are useful for sourcing and configuration interpretation but are not presented as aliases for the original manufacturer identifier.
Identifier
Relationship
Boundary
1305FJ1BCJ2BA
Later Brooks configuration associated with the same defense stock item
Supports decoding the unchanged J1-BC-J2-B-A suffix; it is not presented as the literal identifier printed on every 1305E unit.
NSN 6680-01-263-4067
Government stock-item cross-reference for 1305EJ1BCJ2BA and 1305FJ1BCJ2BA
A procurement identifier, not a Brooks model alias.
G400223-1
Equipment-manufacturer/customer drawing cross-reference under the same stock item
Do not treat as a Brooks model alias without the controlling drawing.
Brooks GT1600 Series
Current Brooks family configurable to retrofit GT130x meters
Replacement selection must match flow range, dimensions, connections, materials, pressure rating, and process conditions; no exact GT1600 ordering code was established.
Installation and Safety Notes
The Model 1305 is a glass-tube instrument and must be installed and operated within the manufacturer's mechanical and fluid-compatibility restrictions.
Mount within 6 degrees of true vertical, with the inlet at the bottom and outlet at the top.
Keep the protective sleeve over the glass tube and fasten the meter windows securely.
Avoid pressure and flow surges, and never service or repair the meter while it is pressurized.
The 250°F rating does not override chemical-compatibility limits. Brooks prohibits use with toxic fluids or fluids that react with glass, including water above 140°F, steam, alkalis, fluorine, hydrofluoric acid, and molten metal.
Install new O-rings whenever the meter is removed for service, then have qualified personnel pressure-test it before returning it to operation.
