u2-Lok Twin ferrule fittings

Bulkhead Union

u2-BU

Fractional or metric tube

Connection 1

Description

The dimensions refer to pipe fittings with hand-tightened nuts and are for reference only. Dimensional deviations reserved.

Technical data & dimensional drawing

Please select connections.

Downloads & CAD

Assembly instructions

Assembly instruction u2 Twin ferrule fittings

CAD

Please select connections.

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u2-C - Union Cross Tube to Tube

u2-Lok Twin Ferrule Fittings

About the successful certification of u2-Lok Twin Ferrule Fittings fittings by DNV · GL (Det Norske Veritas · Germanischer Lloyd), the Schwer Fittings GmbH was delighted. The very extensive type examination included the following tests: Combined pressure pulse and vibration test, repeated assembly, leak testing, vacuum testing, pull test and a burst resistance.

Important information on technical changes, applications, standards and guidelines

The stainless steel u2-Lok compression wedge ring tube fittings are used in high-pressure and vacuum applications where the highest demands are placed on material and tightness. They are suitable for liquid and gaseous media. Also suitable for applications with gaseous hydrogen and certified to EC79 (H2-Lok).

Basically, the u2-Lok screw connection consists of 4 components or individual parts: The media-carrying base body (straight socket, elbow, T-piece or cross piece), the union nut and the two rings, also known as clamping and wedge rings.

The screw connections are used wherever gases and liquid media flow and where a high safety standard is required. It is also ideal for hydrogen applications.

The u2-Lok screw connections are mainly used:

in chemical process technology
in pharmaceutical and biotechnology
in petroleum processing
in offshore and shipbuilding
in nuclear research
in laboratories and institutes
in vacuum technology
for hydrogen applications (Hydrogen H2)

u2-Lok, Klemm-Keilring Verschraubung, Klemmringverschraubung, Klemmring

The new u2 fittings are designed according to its own production facilities in Europe. The semi-finished products are mostly from EU countries. Both the quality and the current pressure tests are carried out exclusively in the company's headquarters in Denkingen.

The design largely allows vibrations and pressure pulses to be absorbed, without any fear of leackage. This design, technical manufacturing, and quality properties ensure twin ferrule fittings a wide range of applications in industry, laboratory, and measurement system areas.

The use of high quality stainless steel guarantees a long service free life, also in the chemical industry. u2-Lok Twin Ferrule Fittings, from 316 stainless steel as standard, are supplied assembled and ready to use. Even under heavy vibration conditions couplings guarantee a safe operation at high pressure or vacuum.

The fittings are delivered ready for use. The nut and the clamping wedge rings of the screw connection do not have to be dismantled for assembly. The union nuts are tightened finger-tight with the clamping and wedge rings on the screw connection body and can therefore be used immediately for assembly. For professional assembly, the assembly instructions must be observed. Repeat assemblies are possible several times.

Even when the system is operated with high vibrations, the screw connection guarantees sufficient safety at high pressures or vacuum.

This is achieved through 4 effective design details:

The back ferrule affords damping of tube circuit vibrations through a spring like action. Furthermore, it prevents a carry-over of tightening torque from the coupling nut to front ferrule.
The front ferrule circumferentially seals the surface between the tube and coupling. Due to the inner taper the front ferrule is pressed into the tube so that a pressure-tight impression is formed.
Silvering of the coupling nut thread prevents seizing of the stainless steel coupling. This allows multi-use of a coupling.
A deep pipe bore, and entry taper, guarantees accurate positioning and centring of the tube.

On request, parts can also be supplied from Hastelloy, Titanium and other highly alloyd materials. Material certification according DIN ISO 10204, ANSI etc., available on reques. Special tests and approvals possible, if required.

Focus on details

The rear wedge ring has a very high surface hardness of up to HV 1,000. The inner cone in the socket is rolled smooth and the surface is compacted, Ra 0.4 max. The external threads are rolled/chased. The silver-plated internal threads of the union nut prevent cold welding and can therefore be easily removed.

Focus in details Klemm Keilring Verschraubungen

Twin Ferrule Fittings

High Surface Hardness

to HV 1.000

Rolled smooth inner cone

Compacted surface Ra 0.4 max

Threads rolled

Traceability

through test and batch number

Silver plated inner thread

on the nut allows for easier removal and prevents cold welding

Schwer Fittings Standard cleaning

As standard, the u2-Lok twin-ferrule fittings are supplied free of oil and grease (off) and individually packed in foil. A special multi-stage cleaning process with ultrasonic support removes oil and grease residues as well as loose particles, ensuring that the components meet the basic requirements of the industry.

When using oxygen, certain precautions must be taken to rule out the risk of fire. The cleanliness of the system plays an important role in preventing an oxygen fire. For such applications, we offer fittings in accordance with the "offO2" Schwer Fittings standard. This in-house standard defines the cleaning, assembly and packaging of stainless steel fittings in accordance with ASTM G93 Level C for all components in contact with media.

Please refer to our more detailed information on the various cleaning standards in the data sheets listed below.

Cleaning Standard off
Cleaning Standard offO2

Certifications

The screw connections from Schwer Fittings are certified by the certification body DNV (Det Norske Veritas). The very extensive type test included the following tests: combined pressure pulse and vibration test, repeat assembly test, leak test, vacuum test, pull-out test and a bursting pressure test.

Own European production

The fittings are manufactured in our own production facilities in Europe. Most of the semi-finished products come from EU countries. Both the quality assurance and the ongoing pressure tests are carried out exclusively at the company headquarters of Schwer Fittings in Denkingen. Pressure test requirements according to customer specifications are carried out and documented at Schwer. A test number is generally lasered into the media-carrying parts including the rings. This number hides a lot of information. In this way, the assignment to the starting material with all mechanical tests and the assignment with a 3.1 certificate can be guaranteed even after years. It is also possible to trace back when, in which production plant, on which machine and by which employee the parts were manufactured.

Interchangeability of twin ferrule fittings and individual components

Twin ferrule fittings are to be considered a complete system, which is why all components within this system are specifically matched to each other. By mixing individual parts from different manufacturers within a fitting, it can no longer be guaranteed that the functionality of the fitting system is reflective of the operating values specified in the catalogue.

Practical experience shows that mixing individual parts can work - however, it should be noted that mixing individual parts from different manufacturers within a fitting will result in the loss of all certifications for the fitting as well as the expiry of all warranty claims. Schwer Fittings therefore recommends not to mix the individual components of twin ferrule fittings from different manufacturers, and always to replace complete fittings. The technical information and specifications in our data sheets and e-shop apply.

Area video

Information from our product management about product variants, function and areas of application.

Assembly Instruction: u2-Lok Twin Ferrule Fittings

The u2-Lok Twin Ferrule Fittings are delivered assembled and ready to use. The nuts and ferrules don’t need to be removed for assembly. The nuts are assembled fingertight to the body and an instant assembly is guaranteed.

Observe the generally applicable safety regulations when handling tools and machines. Wear appropriate protective clothing.

Assembly into a body:

Reassembling:

Quality Management System

In addition to national and international certifications the company Schwer Fittings is additionally certified regularly by customers. Through our own developments and solutions Schwer Fittings has numerous patents and registered designs. Furthermore, we offer the following certificates to download:

Bulkhead Union u2-BU

Bulkhead Union