Overview
Parflow SingleFerrule™ Tube Fittings are engineered to provide dependable, leak-tight tube connections for instrumentation, hydraulic, pneumatic, and general process applications. Designed around a proven single ferrule compression mechanism, these fittings offer a practical and efficient solution for systems where reliability, ease of installation, and long-term serviceability are essential.
Across industrial facilities, instrumentation tubing forms the backbone of pressure measurement, flow monitoring, process control, and fluid transfer systems. The integrity of these systems depends heavily on the quality of every tube connection. Poorly sealed joints can result in leakage, inaccurate measurements, increased maintenance, and unnecessary operational downtime. Parflow SingleFerrule™ Tube Fittings are designed to create secure mechanical connections that maintain sealing performance under normal operating conditions while simplifying installation and maintenance.
Combining precision manufacturing with robust engineering, the Parflow SingleFerrule™ range is well suited for applications requiring consistent performance, compact installation, and economical system design. They are widely used in process industries where medium-pressure instrumentation lines, pneumatic systems, hydraulic circuits, and utility services require dependable tube connections without the complexity of welded or flared joints.
Working principle
The tube is inserted to the internal stop and the compression nut tightened. Axial force drives the single ferrule into the tapered seat of the body, compressing it uniformly around the tube OD, creating the metal-to-metal seal and the mechanical grip in one controlled action.
The four-component system (body, ferrule, nut, tubing) is machined to close tolerances so assembly is fast, repeatable, and requires no welding, flaring, or sealing compounds.
At a glance
The specification tables for the two Parflow ferrule fitting families differ in a few rows that decide the selection. Everything below is quoted from those two tables, neither family states a single working-pressure or temperature figure, because both depend on tube OD, wall thickness, and material.
| SingleFerrule™ (this product) | TwinFerrule™ | |
|---|---|---|
| Design | One ferrule seals and grips | Front ferrule seals, back ferrule grips, independently |
| Working pressure | Varies by fitting size and material | Varies by tube OD, wall and material; up to 60,000 psi (4137 bar) on selected high-pressure series |
| Available sizes | 1/8" to 2" OD; metric equivalents | 1/16" to 2" OD; 2 mm to 50 mm metric |
| Materials | SS316, Brass, Carbon Steel | SS316, SS316L, Brass, Carbon Steel, Duplex & Super Duplex (optional), alloys on request |
| End connections | Tube OD, Male/Female NPT, BSPT, BSPP | Tube OD × Tube OD, Male/Female NPT, BSPT, BSPP, SAE/MS, Socket Weld, Butt Weld |
| Leakage performance | Leak-tight sealing under rated service conditions | Zero-leak design under rated operating conditions |
Specify SingleFerrule for general instrumentation, pneumatic, hydraulic, and utility service, its four-component construction assembles faster and costs less per connection. Move to TwinFerrule when the line needs a stated high-pressure series, a duplex or alloy body, a weld or SAE/MS end, tube below 1/8" OD, or when vibration and thermal cycling make independent seal-and-grip worth the extra part.
Working pressure and temperature are not fixed for this family; both are set by the tube OD, wall thickness, and body material you choose, so confirm the rating against the assembly rather than the fitting alone.
Key features
- Single-ferrule compression design: sealing and retention in one element
- Secure metal-to-metal sealing without welding or brazing
- Compact construction for confined installations
- Suitable for gas and liquid service
- Fast assembly with standard tooling
- Low maintenance, easy servicing
- Wide range of tube sizes, thread types, and configurations
Technical advantages
Parflow SingleFerrule™ Tube Fittings offer an effective balance between performance, simplicity, and cost efficiency. Their straightforward design reduces the number of components while providing dependable sealing performance for a broad range of industrial applications. Installation requires minimal tooling, allowing rapid assembly during new projects as well as maintenance and retrofit work.
The metal-to-metal compression seal provides excellent resistance to leakage under normal operating pressures while eliminating the need for consumable sealing materials. This contributes to lower maintenance requirements and improved long-term reliability. Because the fittings are compact and easy to assemble, they are particularly suited to installations where accessibility is limited or where frequent modifications to tubing systems may be required.
For OEM equipment manufacturers and plant maintenance teams, the single ferrule design provides an economical and reliable connection solution without compromising mechanical integrity for general instrumentation duties.
Applications
- Instrument air systems
- Pneumatic control circuits
- Hydraulic systems
- Utility services & water distribution
- Lubrication systems
- Gas distribution panels
- Laboratory & calibration equipment
- OEM machinery & process skids
Configurations
- Straight unions
- male and female connectors
- elbows
- tees
- crosses
- adapters
- bulkhead fittings
- reducers
- plugs
- caps in standard instrumentation patterns
Industries served
- Oil & Gas
- Petrochemical
- Chemical Processing
- Power Generation
- Water & Wastewater
- Food & Beverage
- Pharmaceutical
- Industrial Automation
- Pulp & Paper
- OEM Manufacturing
Why choose Parflow
Parflow SingleFerrule™ Tube Fittings are designed for engineers and system designers who require dependable tube connections without unnecessary complexity. Combining precision manufacturing with proven compression technology, they provide reliable sealing performance, simplified installation, and long-term durability across a broad spectrum of industrial applications. Whether incorporated into instrumentation panels, utility systems, hydraulic equipment, or OEM machinery, Parflow SingleFerrule™ Tube Fittings deliver the confidence of a secure mechanical connection while supporting efficient installation and straightforward maintenance.
Their versatility, reliability, and practical design make them an integral component of modern industrial fluid and instrumentation systems.
FAQ
When should I choose a single-ferrule over a twin-ferrule fitting?
For general instrumentation, pneumatic, hydraulic, and utility duties at moderate pressures, a precision single-ferrule fitting is efficient and reliable. For severe vibration, high cyclic loading, or very high pressure, evaluate a twin-ferrule system.
How does one ferrule both seal and grip?
As the nut drives the ferrule into the body's tapered seat, controlled deformation creates a metal-to-metal seal against the body while the ferrule edge bites into the tube for retention, one element, two functions.
What services are SingleFerrule™ fittings suitable for?
Gas and liquid service across instrumentation, hydraulic, and pneumatic systems: instrument air, utilities, lubrication, gas panels, laboratory and OEM equipment.