Single Ferrule Tube Fitting Manufacturer, Supplier & Exporter
A single ferrule compression fitting joins metal tubing with one ferrule that both grips the tube and forms the seal. Raaj Fittings manufactures and exports single ferrule tube fittings in SS 316L, SS 304, duplex, carbon steel and nickel alloys, in metric tube sizes from 3 mm to 25 mm OD and imperial sizes from 1/8" to 1" OD.
With fewer parts than a double ferrule fitting, the single ferrule design is simple and quick to assemble, and it is well suited to general instrumentation, process control and utility tubing where the redundancy of a second ferrule is not required.
Our single ferrule fittings are dimensionally compatible with Parker® A-LOK® connections. All fittings are supplied with EN 10204 3.1 mill test certificates and full material traceability.
We export single ferrule compression fittings to instrumentation contractors, OEMs and distributors across the Middle East and GCC, Europe and the Americas, in metric and imperial tube sizes with NPT or BSP ends to suit each market.
Single Ferrule Fittings Specifications
3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22 and 25 mm
1/8", 3/16", 1/4", 5/16", 3/8", 1/2", 5/8", 3/4" and 1"
Up to 207 bar (3,000 psi); rating depends on tube OD, wall thickness, material and temperature
Tube compression ends; NPT, BSPT and BSPP threaded ends
Body, nut and single ferrule
Dimensionally compatible with Parker® A-LOK® connections
Precision-machined from bar stock on CNC machines
EN 10204 3.1 mill test certificate; EN 10204 3.2 on request
Materials & Grades
We supply single ferrule compression fittings in the following materials and grades. All grades are supplied with EN 10204 3.1 / 3.2 Mill Test Certificates.
Stainless Steel Single Ferrule Compression Fittings
Stainless steel is the standard material for instrumentation tube fittings across oil and gas, petrochemical, pharmaceutical, and offshore applications. SS 316L is the most widely specified grade.
The industry default for instrumentation tube fittings — low carbon content prevents sensitisation; molybdenum addition provides superior chloride and acid resistance versus 304 grades.
Superior chloride and acid resistance — used where chloride exposure, marine atmosphere, or mild chemical service requires better corrosion resistance than 304.
General corrosion resistance at lower cost than 316L — suitable for water, steam, mild chemical, and food-grade applications where chloride exposure is limited.
Duplex & Super Duplex Stainless Steel Single Ferrule Compression Fittings
Duplex and super duplex grades provide approximately twice the yield strength of 316L with excellent resistance to chloride stress corrosion cracking — the preferred choice for offshore and subsea instrumentation where standard 316L may be susceptible to SCC.
(UNS S31803 / S32205) Offshore topsides instrumentation, seawater injection, and chemical injection systems
(UNS S32750) Subsea instrumentation, high-chloride offshore service, and FPSOs — PREN ≥ 42
Nickel Alloy Single Ferrule Compression Fittings
For aggressive chemical, sour gas, and high-temperature service where duplex stainless steel is insufficient — specified in chemical injection, downhole instrumentation, and severe process environments.
(UNS N06625) Outstanding corrosion resistance in offshore, subsea, and chemical service; widely specified for downhole instrumentation and subsea chemical injection tubing
(UNS N10276) Broad-spectrum resistance to aggressive acids, chlorides, and oxidising media; chemical and FGD process sample systems
(UNS N04400) Hydrofluoric acid service, seawater, and marine instrumentation systems
(UNS N08020) Sulfuric acid and aggressive chemical process sample and instrumentation systems
Carbon Steel Single Ferrule Compression Fittings
Carbon steel tube fittings are used in hydraulic systems, compressed air, general industrial service, and non-corrosive process applications where stainless steel is not required.
Precision-machined carbon steel bar stock — used in hydraulic circuits, compressed air distribution, and general industrial instrumentation where corrosion resistance is not required.
Electroplated zinc or phosphated finish for enhanced surface corrosion protection — used in carbon steel DIN 2353 hydraulic fittings and general instrumentation in non-aggressive environments.
How a Single Ferrule Fitting Works
As the nut is tightened, it drives the ferrule into the conical seat of the fitting body. The leading edge of the ferrule is forced inwards onto the tube, where it both grips the tube surface and seals against the body seat. One component therefore provides both the holding force and the leak-tight seal.
- Fewer components — body, nut and one ferrule; less to stock and assemble.
- Quick assembly — fewer parts to align, so installation is fast.
- Reliable sealing — metal-to-metal seal for liquids and gases in general service.
- Remakeable — can be disconnected and retightened for maintenance.
Single or Double Ferrule?
Single ferrule fittings are rated up to 207 bar (3,000 psi) and suit general instrumentation, utility air and process control lines. Where higher pressure, strong vibration or sour and critical service call for dual-seal redundancy, a double ferrule fitting is preferred. For metric hydraulic systems built to European practice, DIN 2353 bite type fittings are another option.
Configurations
Single ferrule fittings are available as union connectors, male and female connectors, union elbows, union tees, bulkhead unions and reducing unions. Always use the ferrule and nut supplied for the fitting, and do not mix components from different fitting systems.
Parker® and A-LOK® are registered trademarks of Parker Hannifin Corporation. Our products are not manufactured by or affiliated with Parker Hannifin.
Applications & Industries
- General instrumentation and process control tubing
- Pneumatic and utility air lines
- Lubrication and cooling-water tubing on machinery
- Sampling and analyser connections in non-critical service
- Water treatment and HVAC instrumentation
For reliable joints, use annealed tubing of suitable hardness and a wall thickness rated for the working pressure, and tighten the nut by the specified amount. Single ferrule fittings are often chosen for large quantities of general instrumentation because of their simple assembly.
When ordering, give the fitting type, tube OD, any thread size and form, and the material grade. See all tube fittings we manufacture.
Testing, Inspection, Marking & Packing
Single ferrule fittings are produced under our quality assurance process:
- Bar stock verified by PMI testing, with full chemical and mechanical traceability
- Dimensional inspection of body seat, ferrule profile, nut threads and hex sizes
- Thread gauging of NPT, BSPT and BSPP ends
- Pressure testing on request
- Marking with material grade and heat code
Supplied with EN 10204 3.1 mill test certificates; EN 10204 3.2 certificates and third-party inspection on request.
Fittings are capped and bagged to keep ports clean, then boxed and packed in seaworthy wooden cases for export; marking, tagging and packing to your specification are available on request.
Why Choose Raaj Fittings for Single Ferrule Compression Fittings?
Raaj Sagar Steels has supplied piping components since 2003 and today manufactures tube fittings at two plants in India for buyers in the Middle East, Europe and the Americas.
- Manufactured in-house — Single ferrule compression fittings are made in our own plants, so material, dimensions and delivery stay under our control.
- Ready stock, short lead times — common sizes and grades are held in stock for prompt dispatch; other sizes, grades and specials are manufactured to order.
- Certified quality — ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified; PED 2014/68/EU supply available, and NACE MR0175 / ISO 15156 material on request.
- 100% material verification — PMI testing on incoming material and EN 10204 3.1 mill test certificates with every order; 3.2 certificates on request.
- Third-party inspection ready — we regularly work with SGS, Bureau Veritas, TÜV and DNV.
- Export documentation — MTCs, certificates of origin, packing lists and inspection reports to suit projects in the GCC, Europe and the Americas.
- Export packing — seaworthy packing with end and face protection, and packing to your specification on request.
- Fast response — our team replies to enquiries within one business day.
Single Ferrule Compression Fittings — FAQs
It is a tube fitting with one ferrule that both grips the tube and seals against the fitting body when the nut is tightened.
Up to 207 bar (3,000 psi), depending on tube OD, wall thickness, material and temperature.
For general instrumentation and process service where the extra redundancy of a second ferrule is not required. For critical, high-pressure or sour service, choose double ferrule.
Yes, they are dimensionally compatible with Parker® A-LOK® connections. Use matched ferrules and nuts within each joint.
SS 316L, SS 316, SS 304 / 304L, duplex 2205, super duplex 2507, carbon steel and nickel alloys such as Inconel 625 and Monel 400.
Yes. We supply single ferrule compression fittings for projects under the European Pressure Equipment Directive (PED 2014/68/EU), with EN 10204 3.1 certificates as standard and 3.2 on request. NACE MR0175 / ISO 15156 compliant material is available for sour service in the Middle East and the Americas.
