Connecting two unequal tube outside diameters in a single streamlined body, Pioneer Industries Brass Double Ferrule Reducing Unions eliminate multi-fitting adaptation assemblies while ensuring zero-leakage performance under severe vibration and pressure cycling.
The Brass Double Ferrule Reducing Union directly couples two lengths of tubing of different outside diameters along a single straight axis. Each port features a dedicated twin-ferrule mechanical compression assembly precisely sized for its respective tubing diameter.
Engineered from high-tensile brass bar stock (ASTM B16 C36000) or hot-forged brass (ASTM B283), this fitting eliminates the need for compounding adapters or bushings, delivering an unobstructed flow profile with minimal pressure loss and absolute containment integrity up to 5,000 PSI.
Exported internationally by Pioneer Industries Mumbai to control panel builders, pneumatic system integrators, and industrial machinery manufacturers.
Components are precision CNC-machined from premium extruded brass (IS 319 / ASTM B16 / CW614N) with micro-smooth surface finishes. Every production lot undergoes rigorous metallurgical spectrometry, optical CMM dimensional checks, and helium leak detection, accompanied by authentic EN 10204 Type 3.1 Mill Test Certificates.
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Precision CNC-machined internal bores ensure smooth, concentric fluid flow between differing tube IDs, preventing turbulence and pressure surges.
Each tube port operates independently, allowing distinct tubing wall thicknesses and materials (such as brass, copper, or nylon) to be secured with equal sealing efficacy.
Metric tubing 6 mm to 25 mm OD (MPRU Series) and fractional tubing 1/8" to 1" OD (IPRU Series) across standard reduction combinations.
Explore comprehensive engineering dimensional configurations for Metric Series and Fractional Series, Operating Parameters, and Certified Metallurgy. Manufactured according to ASME B31.3, ISO 19879, and international instrumentation standards.
| Part No. | Tube O.D. | E mm | h mm | H mm | H 1 mm | F | F 1 | G | G 1 | l | L | Working Pressure | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| T mm | T1 mm | 5,000 PSI / 345 Bar | |||||||||||
| MPRU-06-03 | 6 | 3 | 2.4 | 14 | 14 | 12 | 15.3 | 12.9 | 17.7 | 15.3 | 24.6 | 38.6 | 5,000 PSI / 345 Bar |
| MPRU-06-04 | 6 | 4 | 2.4 | 14 | 14 | 12 | 15.3 | 13.7 | 17.7 | 16.1 | 25.4 | 39.4 | 5,000 PSI / 345 Bar |
| MPRU-08-06 | 8 | 6 | 4.8 | 15 | 16 | 14 | 16.2 | 15.3 | 18.6 | 17.7 | 27.4 | 42.3 | 5,000 PSI / 345 Bar |
| MPRU-10-06 | 10 | 6 | 4.8 | 18 | 19 | 14 | 17.2 | 15.3 | 19.5 | 17.7 | 29.5 | 44.5 | 5,000 PSI / 345 Bar |
| MPRU-10-08 | 10 | 8 | 6.4 | 18 | 19 | 16 | 17.2 | 16.2 | 19.5 | 18.6 | 30.0 | 45.1 | 5,000 PSI / 345 Bar |
| MPRU-12-06 | 12 | 6 | 4.8 | 22 | 22 | 14 | 22.8 | 15.3 | 22.0 | 17.7 | 29.5 | 47.0 | 5,000 PSI / 345 Bar |
| MPRU-12-08 | 12 | 8 | 6.4 | 22 | 22 | 16 | 22.8 | 16.2 | 22.0 | 18.6 | 30.2 | 47.8 | 5,000 PSI / 345 Bar |
| MPRU-12-10 | 12 | 10 | 7.9 | 22 | 22 | 19 | 22.8 | 17.2 | 22.0 | 19.5 | 31.0 | 48.7 | 5,000 PSI / 345 Bar |
| MPRU-16-12 | 16 | 12 | 9.5 | 24 | 25 | 22 | 24.4 | 22.8 | 22.0 | 22.0 | 31.8 | 52.0 | 5,000 PSI / 345 Bar |
| MPRU-25-18 | 25 | 18 | 15.1 | 35 | 38 | 30 | 31.3 | 24.4 | 26.5 | 22.0 | 38.6 | 61.0 | 5,000 PSI / 345 Bar |
| MPRU-25-20 | 25 | 20 | 15.9 | 35 | 38 | 32 | 31.3 | 26.0 | 26.5 | 22.0 | 39.9 | 62.3 | 5,000 PSI / 345 Bar |
| Part No. | Tube O.D.T in | Tube O.D.T T1 in | E Min | h in | H in | H 1 in | F | F 1 | G | G 1 | l | L | Working Pressure |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| IPRU-02-01 | 1/8 | 1/6 | 1.27 | 7/16 | 7/16 | 5/16 | 12.7 | 8.63 | 15.24 | 10.92 | 20.60 | 30.91 | 5,000 PSI / 345 Bar |
| IPRU-03-02 | 3/16 | 1/8 | 2.28 | 7/16 | 1/2 | 7/16 | 13.71 | 12.70 | 16.00 | 15.24 | 23.36 | 36.57 | 5,000 PSI / 345 Bar |
| IPRU-04-02 | 1/4 | 1/8 | 2.28 | 1/2 | 9/16 | 7/16 | 15.24 | 12.70 | 17.78 | 15.24 | 24.63 | 38.60 | 5,000 PSI / 345 Bar |
| IPRU-04-03 | 1/4 | 3/16 | 3.04 | 1/2 | 9/16 | 1/2 | 15.24 | 13.71 | 17.78 | 16.00 | 25.40 | 39.37 | 5,000 PSI / 345 Bar |
| IPRU-05-02 | 5/16 | 1/8 | 2.28 | 9/16 | 5/8 | 7/16 | 16.25 | 12.70 | 18.54 | 15.24 | 25.90 | 39.87 | 5,000 PSI / 345 Bar |
| IPRU-05-04 | 5/16 | 1/4 | 4.82 | 9/16 | 11/16 | 9/16 | 16.25 | 15.24 | 18.54 | 17.78 | 27.43 | 42.16 | 5,000 PSI / 345 Bar |
| IPRU-06-02 | 3/8 | 1/8 | 2.28 | 5/8 | 11/16 | 7/16 | 16.76 | 12.70 | 19.30 | 15.24 | 26.92 | 40.89 | 5,000 PSI / 345 Bar |
| IPRU-06-04 | 3/8 | 1/4 | 4.82 | 5/8 | 11/16 | 9/16 | 16.76 | 15.24 | 19.30 | 17.78 | 28.44 | 43.18 | 5,000 PSI / 345 Bar |
| IPRU-06-05 | 3/8 | 5/16 | 6.35 | 5/8 | 7/8 | 5/8 | 16.76 | 16.25 | 19.30 | 18.54 | 29.46 | 44.19 | 5,000 PSI / 345 Bar |
| IPRU-08-02 | 1/2 | 1/8 | 2.28 | 13/16 | 7/8 | 7/16 | 22.86 | 12.70 | 21.84 | 15.24 | 28.44 | 45.21 | 5,000 PSI / 345 Bar |
| IPRU-08-04 | 1/2 | 1/4 | 4.82 | 13/16 | 7/8 | 9/16 | 22.86 | 15.24 | 21.84 | 17.78 | 29.46 | 46.99 | 5,000 PSI / 345 Bar |
| IPRU-08-06 | 1/2 | 3/8 | 7.11 | 13/16 | 1 | 11/16 | 22.86 | 16.76 | 17.78 | 19.30 | 30.98 | 48.51 | 5,000 PSI / 345 Bar |
| IPRU-10-06 | 5/8 | 3/8 | 7.11 | 15/16 | 1 | 11/16 | 24.38 | 16.76 | 21.84 | 19.30 | 31.75 | 49.27 | 5,000 PSI / 345 Bar |
| IPRU-10-08 | 5/8 | 1/2 | 10.41 | 15/16 | 1-1/8 | 7/8 | 24.38 | 22.86 | 21.84 | 21.84 | 31.75 | 52.07 | 5,000 PSI / 345 Bar |
| IPRU-12-04 | 3/4 | 1/4 | 12.70 | 1-1/16 | 1-1/8 | 9/16 | 24.38 | 15.24 | 21.84 | 17.78 | 31.75 | 49.27 | 5,000 PSI / 345 Bar |
| IPRU-12-06 | 3/4 | 3/8 | 7.11 | 1-1/16 | 1-1/8 | 11/16 | 24.38 | 16.76 | 21.84 | 19.30 | 33.27 | 50.80 | 5,000 PSI / 345 Bar |
| IPRU-12-08 | 3/4 | 1/2 | 10.41 | 1-1/16 | 1-1/8 | 7/8 | 24.38 | 22.86 | 21.84 | 21.84 | 33.27 | 53.59 | 5,000 PSI / 345 Bar |
| IPRU-12-10 | 3/4 | 5/8 | 12.70 | 1-1/16 | 1-1/8 | 1 | 24.38 | 24.38 | 21.84 | 21.84 | 33.27 | 53.59 | 5,000 PSI / 345 Bar |
| IPRU-16-08 | 1 | 1/2 | 10.41 | 1-3/8 | 1-1/2 | 7/8 | 31.24 | 22.86 | 26.41 | 21.84 | 40.89 | 63.24 | 5,000 PSI / 345 Bar |
| IPRU-16-12 | 1 | 3/4 | 19.05 | 1-3/8 | 1-1/2 | 1-1/8 | 31.24 | 24.38 | 26.41 | 21.84 | 40.38 | 62.73 | 5,000 PSI / 345 Bar |
| Operating Parameter | Standard Specification | Severe Service / High-Pressure Rating |
|---|---|---|
| Fluid Media Compatibility | Compressed Air, Mineral Oils, Hydraulic Fluids, Inert Gases | Natural Gas, Vacuum lines, Steam & Glycol circuits |
| Working Pressure Range | Vacuum to 5,000 PSI (345 Bar) depending on tube size | Proof pressure tested to 1.5× design working pressure |
| Helium Leak Integrity | < 1 × 10⁻⁹ mbar·l/s | Suitable for ultra-clean analytical & vacuum systems |
| Temperature Envelope | -200°C to +200°C (-328°F to +392°F) | Cryogenic to moderate steam and hot oil service |
| Turns From Finger-Tight | 1-1/4 Turns (sizes 1/4" to 1" / 6mm to 25mm) | 3/4 Turn (sizes 1/16" to 3/16" / 2mm to 4mm) |
| Compatible Tubing | Seamless Copper (ASTM B75, B88), Brass (ASTM B135) | Nylon, PU, PTFE (with Pioneer brass tube inserts) |
Pioneer Industries manufactures Brass Double Ferrule Reducing Union using high-tensile extruded brass bar stock and forgings with controlled microstructural annealing:
| Component / Grade | Material Standard | Composition / Chemistry |
|---|---|---|
| Fitting Body / Bar | ASTM B16 / IS 319 Gr. 1 / CW614N | Cu: 60.0–63.0%, Pb: 2.5–3.7%, Fe: 0.35% Max, Zn: Balance |
| Forged Elbows / Tees | ASTM B283 / CW617N C37700 | Cu: 57.0–60.0%, Pb: 1.5–2.5%, Fe: 0.30% Max, Zn: Balance |
| Front & Back Ferrules | ASTM B16 / Cold-Worked Annealed | Controlled Alpha-Beta phase balance for clean collet swaging |
| Optional Naval Brass | ASTM B21 / CW712R C46400 | Cu: 59.0–62.0%, Sn: 0.5–1.0%, Pb: 0.20% Max, Zn: Balance |
Our manufacturing, swaging tolerances, and quality verification strictly adhere to international engineering benchmarks:
Brass Double Ferrule Reducing Union components are deployed across demanding industrial instrumentation, process lines, and pneumatic circuits, including:
Stepping down 1/2″ or 3/8″ supply lines to 1/4″ instrument impulse tubing.
Connecting larger air distribution tubing to compact cylinder control lines.
Downsizing flow lines to match heat exchanger coil inlet diameters.
Transitioning from primary pump feed tubing to localized bearing feeder lines.
Downsizing from 1/4″ bulk carrier gas lines to 1/8″ analytical columns.
Transitioning between high-volume reservoir lines and brake actuator tubing.
Reliable, vibration-proof diameter transitions in engine room monitoring circuits.
Quickly transitioning between bench supply tubing and smaller test specimen ports.
Pioneer Industries’ Brass Double Ferrule Reducing Union components are trusted across critical global industrial sectors:
Expert engineering insights and technical guidance regarding swaging mechanics, pressure thresholds, tubing compatibility, and installation protocols for Brass Double Ferrule Reducing Union.
A Brass Double Ferrule Reducing Union is a straight coupling fitting that joins two bare tubes of different outside diameters using double-ferrule compression assemblies on each end.
A reducing union connects two bare tubes of different sizes. A reducer has one compression tube port and one bare tube stub intended to insert into another fitting port.
Metric Series MPRU covers 6mm to 25mm steps (e.g., 10mm × 6mm, 12mm × 8mm), and Fractional Series IPRU covers 1/8″ to 1″ combinations (e.g., 3/8″ × 1/4″, 1/2″ × 3/8″, 1/2″ × 1/4″).
Rated up to 5,000 PSI (345 Bar) for sizes 1/8″ to 1/4″ and 3,200 PSI for 1/2″, determined by the smaller tube size per ASME B31.3.
Manufactured from extruded brass bar stock ASTM B16 Alloy C36000 or forged brass ASTM B283 CW617N.
Each end is installed independently: bottom the tube against the internal shoulder, hand-tighten the nut, and tighten 1-1/4 turns with a wrench (3/4 turn for sizes 1/8″ and 3/16″).
Yes. Both compression joints can be remade independently multiple times by tightening approx. 1/12 to 1/6 turn past finger-tight.
No. The internal bore is CNC-machined with a gradual conical taper to ensure laminar fluid flow and minimal pressure differential.
Yes, precision twin-ferrule mechanical swaging ensures vacuum sealing down to 1 × 10⁻⁹ mbar·l/s.
Every lot is accompanied by EN 10204 Type 3.1 Material Test Certificates, hydrostatic test records, and dimensional reports.
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Note: Please note that the information on this document is for illustration purposes only as information may vary with individual products, their grade and applications industries or uses and therefore cannot be guaranteed as accurate. © Copyright 2026 by Pioneer Industries. All Rights Reserved.
