Pipe Fittings
Reducing Bushing
316 stainless steel reducing bushing for connecting a larger female-threaded port to a smaller male-threaded component or connection. Available in Male NPT × Female NPT and selected ISO/BSP tapered-thread configurations for instrumentation, process and industrial fluid systems.
Specifications
- Series
- TRB Series
- Fitting Type
- Reducing Bushing
- Configuration
- Larger Male Thread × Smaller Female Thread
- Primary Configuration
- Male NPT × Female NPT
- NPT Standard
- ASME B1.20.1
- Available Thread Types
- NPT and ISO/BSP Tapered
- Standard Material
- 316 Stainless Steel
- Material Specification
- ASTM A276 Bar Stock
- Body Construction
- Machined from Bar Stock
- Working Pressure
- Size and configuration dependent
Overview
The TRB Series Reducing Bushing is a straight pipe fitting designed to reduce the connection size at a threaded port.
The larger male thread installs into the corresponding female port, while the smaller internal female thread accepts a smaller male-threaded fitting, valve, instrument or other component. This provides a compact transition between different pipe-thread sizes without requiring a separate coupling and reducer.
Male NPT × Female NPT is the primary configuration. Selected Male ISO/BSP Tapered × Female ISO/BSP Tapered configurations are also available.
Key Features
- Larger male thread × smaller female thread configuration
- Compact transition between different pipe-thread sizes
- Male NPT × Female NPT configurations
- Selected ISO/BSP tapered-thread configurations
- NPT threads based on ASME B1.20.1
- Hex body for wrench installation
- 316 stainless steel as the standard material
- Straight body machined from bar stock
- Multiple reducing combinations for instrumentation and process connections
Engineering Specifications
Parameter | Specification |
|---|---|
Product Type | Reducing Bushing |
Series | TRB |
Body Style | Straight Hex Body |
Connection | Male Thread × Female Thread |
Primary Configuration | Male NPT × Female NPT |
NPT Standard | ASME B1.20.1 |
Additional Configuration | Male ISO/BSP Tapered × Female ISO/BSP Tapered |
Standard Material | 316 Stainless Steel |
Material Specification | ASTM A276 Bar Stock |
Working Pressure | Dependent on specific thread-size combination |
Representative NPT Configurations & Working Pressure
Working pressure varies according to the specific combination of male and female thread sizes. Representative Male NPT × Female NPT configurations in 316 stainless steel include:
Male NPT | Female NPT | Working Pressure |
|---|---|---|
1/8 in. | 1/16 in. | 6,500 psi / 447 bar |
1/4 in. | 1/16 in. | 8,000 psi / 551 bar |
1/4 in. | 1/8 in. | 6,500 psi / 447 bar |
3/8 in. | 1/16 in. | 13,300 psi / 917 bar |
3/8 in. | 1/8 in. | 9,200 psi / 633 bar |
3/8 in. | 1/4 in. | 6,600 psi / 454 bar |
1/2 in. | 1/8 in. | 12,200 psi / 840 bar |
1/2 in. | 1/4 in. | 8,300 psi / 571 bar |
1/2 in. | 3/8 in. | 5,300 psi / 365 bar |
3/4 in. | 1/2 in. | 4,900 psi / 337 bar |
1 in. | 3/4 in. | 5,300 psi / 365 bar |
1 1/4 in. | 1 in. | 3,500 psi / 241 bar |
1 1/2 in. | 1 in. | 6,600 psi / 454 bar |
1 1/2 in. | 1 1/4 in. | 5,000 psi / 344 bar |
Additional reducing combinations are available within the TRB Series.
Working-pressure ratings are specific to the thread-size combination, material and configuration. They should not be interpreted as a single pressure rating for all bushings of the same male thread size. The allowable working pressure of a complete system is limited by its lowest-rated component and the applicable operating conditions.
Thread Configurations
Available configurations include:
- Male NPT × Female NPT
- Male ISO/BSP Tapered × Female ISO/BSP Tapered
Available size combinations depend on the selected thread standard and required reduction.
Size Selection
A Reducing Bushing is specified by the larger male thread first and the smaller female thread second.
For example:
1/2 in. Male NPT × 1/4 in. Female NPT
This configuration installs into a 1/2 in. female NPT port and provides a 1/4 in. female NPT connection for the mating component.
Both connection sizes and thread standards should be confirmed before ordering.
Thread & Sealing Considerations
NPT is a tapered pipe thread. Sealing is developed through thread engagement together with a thread-sealing method appropriate for the fluid, temperature and operating conditions.
ISO/BSP tapered threads also use a tapered-thread connection but should not be assumed interchangeable with NPT. Thread form, pitch and dimensional standard must match the mating connection.
Nominal thread diameter alone is not sufficient for thread identification. The thread standard and size should be verified before installation.
Material
Standard Material: 316 Stainless Steel
TRB Series Reducing Bushings are machined from 316 stainless steel bar stock to ASTM A276.
316 stainless steel provides corrosion resistance and mechanical performance for a wide range of instrumentation, process and industrial fluid applications.
Typical Applications
Reducing Bushings are commonly used in:
- Instrumentation connections
- Valve and manifold connections
- Process piping
- Pumps and process equipment
- Hydraulic and utility systems
- Test equipment
- Industrial fluid handling systems
Selection & Ordering Information
To specify the required Reducing Bushing, provide:
- Male thread type and size
- Female thread type and size
- Material
- Required working pressure
- Operating temperature
- Fluid or process medium
- Quantity
For unusual configurations, specify the exact thread standard for both connections rather than nominal sizes alone.
Existing part numbers, drawings, BOMs or product references can also be provided for product matching and quotation review.
