R-2-15-D is a Brooks Instrument size-2 rib-guided borosilicate metering-tube identifier used in glass-tube variable-area flowmeter assemblies. Official Brooks documentation lists the exact R-2-15-D tube with five possible float materials and float-dependent reference capacities, while Sho-Rate documentation associates the corresponding tube selection with the 150 mm Model 1355 family. The identifier does not by itself define the installed float, scale calibration, end-block material, seals, connections, valve, pressure certification, or complete flowmeter model. Stored auction records describe 1355 Sho-Rate 150 assemblies marked R-2-15-D and 150 PSI; those details are retained only as observed configuration context and must be checked on the physical meter
Configurations vary. Verify the exact unit before choosing a replacement.
Device typeGlass metering tube for variable-area flowmeters
Configuration statusConfiguration varies
Application classIndustrial automation and process equipment
CategoryFlow Control
Specifications
Identification
Tube identifier
R-2-15-D
Component type
Size-2 rib-guided borosilicate glass metering tube for a variable-area flowmeter
Sho-Rate family context
Brooks documentation associates the R-2-15-D tube selection with the 150 mm Model 1355 family; current revision-G documentation writes the corresponding tube as R-2-15-D G
Measurement
Measuring principle
Variable area: flow is indicated by a float rising in a tapered glass metering tube
Materials
Metering tube
Borosilicate glass
Configuration
Documented float materials
Glass, sapphire, 316 stainless steel, Carboloy, or tantalum; the installed float must be identified before assigning a reference capacity
Configured-unit rule
Verify the complete model code, tube revision, float material, scale or calibration table, process fluid, pressure and temperature basis, end blocks, seals, connections, valve or controller, and tube condition on the physical flowmeter
Flow
Exact-tube water capacities
Brooks R-2-15-D table lists maximum water capacities of 5.58, 10.20, 19.80, 31.90, and 34.40 cc/min for glass, sapphire, stainless-steel, Carboloy, and tantalum floats respectively
Exact-tube air capacities
Brooks R-2-15-D table lists maximum air capacities of 361, 491, 790, 1170, and 1250 scc/min for glass, sapphire, stainless-steel, Carboloy, and tantalum floats respectively, at 14.7 psia and 70 F (21 C)
Revision boundary
Current R-2-15-D G documentation gives slightly revised reference capacities; use the tube revision, installed float, direct-read scale, and calibration record for the physical assembly rather than treating either table as universal
Performance
1355 family accuracy context
Legacy 1355E documentation lists standard accuracy of +/-5% full scale and 0.5% full-scale repeatability; current 1355G documentation lists +/-3% accuracy at reference conditions and 0.25% full-scale repeatability. These are assembly/revision specifications, not standalone guarantees for an unidentified tube-and-float combination
Pressure and temperature
1355 family context
Brooks 1355 documentation lists 200 psig from 33 to 250 F (1 to 121 C), with legacy CRN documentation listing 170 psig; actual assembly materials, seals, revision, certification, and condition govern the usable limit
Documents
Hosted official documentation
Brooks manuals and data sheets containing the exact tube table and relevant Sho-Rate 1355 family context are hosted locally
