SRJ Snap Ring Joint

The weld-free Snap Ring Joint (SRJ) solves many of the problems commonly associated with welded and flanged joints in pipelines and process piping. It can be used in both new lay and established pipework, as a temporary or permanent solution.

SRJ Snap Ring Joint

  • SRJ-Techologies
    A range of simple, yet highly innovative connecting and repair solutions.
  • SRJ-Techologies
    A range of simple, yet highly innovative connecting and repair solutions.
  • SRJ-Techologies
    A range of simple, yet highly innovative connecting and repair solutions.


The range of non-welded pipe connections developed by Snap Ring Joint Limited constitutes a breakthrough in the drive for low weight mechanical connectors able to handle high line pressures.

By eliminating welding, the SRJ gives operators of offshore and onshore infrastructure the flexibility to carry out modifications and essential maintenance on process pipework with minimal disruption to operations. Pipe repair and modification work can be done while the installation is live and without recourse to costly ATEX compliance measures. By eliminating welding there is no need to compress essential work scopes into planned shutdown periods.

For life extension work on space-constrained platforms, where it is necessary to replace or add additional process and utility capacity, while minimising loading, the SRJ provides a secure, robust, leak-free and pressure-tight connection, combining strength with a smaller volume and much lower weight than a comparable flange.

In development for over four years, the design brief for the SRJ was a connector that would be straightforward to install, one that could match the strength, the design life and the material specifications of the adjacent pipework, and one that would create the smoothest possible pipe bore.

The SRJ connector gained Lloyds Register and American Bureau of Shipping Type Approval following comprehensive and strenuous testing under the IACS P2 regime. The IACS standards cover pressure-containing equipment, so the SRJ coupling complies with the European Pressure Equipment Directive (PED). It is also compliant with the industry standard, ASME B31.3.

The SRJ concept is versatile and the complete product catalogue features a host of configurations.

The quality of any engineered product is crucial, and is therefore at the centre of everything Snap Ring Joint Limited does. This means that every product is designed and manufactured in accordance with ISO 9001:2008 (Quality Management).

As well as the existing product range and current developments, Snap Ring Joint Limited are passionate about developing new custom products to cater for specific applications.

Contact SRJ Limited to discuss your application.

Operating Principle and Key Features

The SRJ coupling comprises a single sleeve that spans the two pipe ends and which houses the coupling’s sealing and gripping elements. The grip is provided by retaining wires located in grooves in the body of the connector and corresponding grooves machined into the periphery of the pipe.


The connector wall thickness acts as a supporting sleeve that compensates for the grooves in the pipe OD. This concept increases the strength of the connector by diameter x 3.14 (shear strength). The sealing system comprises high integrity elastomeric seals -currently available in HNBR (Nitrile) or Viton - which are capable of sealing high pressures and against a range of pipeline media.

The HNBR seal is based on casing sealing technology and is energized during coupling installation, while the Viton seal is of a pressure energized lip seal design. A metal seal version is in development, for higher temperature, CO2 and sour service applications.

Pipe to Pipe Coupling

Pipe to Pipe

Direct replacement for butt welded connections.

Pressure Test Cap

Pressure Test Cap

Ideal when capping pipe work to facilitate a pressure test or to simply blank an open ended pipe, thus avoiding the cost, risk and time involved in welding a dome end or flange to the pipe.

Flange Transition Unit

Flange Transition Unit

Connects a bare pipe end to a pre-flanged component. It is ideal for connecting to flanged piping components such as valves

Operating Principle and Key Features


To install the connector (supplied pre-fitted with radial seals), the pipe ends are cut and prepared with the use of a conventional clamshell cutting machine. This machine, fitted with form tools, is used to machine the grooves required to locate the connector’s retaining wires in the pipe periphery.

If access is available at the pipe ends and one of the pipes can be moved longitudinally, then the SRJ connector would be installed onto one of the pipes to half its ength and the mating pipe is then pulled into the connector.

If however, the pipes cannot be pulled longitudinally, i.e. a spooled installation between two fixed ends, the connector would be completely assembled onto one of the pipes. This would leave its outer end flush with the pipe end. Then the mating pipe would be lowered into position and when the pipe ends are butted, then then the connector is centralised.

For larger OD connectors, a hydraulically-activated unit is used to position the connector on the pipe, thereby eliminating seal friction.

Alternatively, normal manual pipe handling equipment can be used. In all cases, once in position, the SRJ connector is locked in place by fitting the retaining wires. Typically, the overall length of the SRJconnector is equal to twice the pipe’s OD, so the actual access requirements are kept to a minimum, making its use ideal in tight access situations, such as the hook up phase of a project.


Nominal Pipe Diameter Pipe OD SRJ Diameter
114.3 mm
203.2 mm
219.075 mm
304.8 mm
323.85 mm


Benefits & Advantages



  • Cold work installation – eliminates the risk associated with Welding.
  • Reduces risk of fugitive emissions
Size / Weight
  • 40/50% more compact than a comparable flange. Closer pipe runs.
Speed of Installation
  • approx 3 hours per coupling with less skilled technicians.
Cost Reduction
  • Time savings 18/24 hours per connection compared to welded flange.


The SRJ offers many benefits over other pipe connection methods: –
  • Withstands high internal pressures and has equivalent mechanical strength of a weld
  • Eliminates costly welding workscopes by replacing coded welders with trained operatives
  • Speed of installation compared to welding workscope
  • Enhances safety on-site and ATEX requirements by eliminating the risks of welding
  • Does not compromise internal pipe coating, unlike welding
  • Avoids the need to weld difficult materials such as CuNi, Monel and Duplex
  • Potential for testing post-installation with the SRJ equipped with integrity ports
  • Lightweight and compact, cutting transport costs and enabling closer pipe rack design
  • Can be dismantled and reassembled

Installation Times vs. Welding

10” 900Lb
Pipe Cutting and Preparation
Pipe Alignment
Flange alignment and welding per flange
Pre Heat
Stress relieve
Coupling Installation
Connecting flanges / gaskets / bolts
Total Hours
SRJ Saving

Note – Pipe preparation times for SRJ and welding considered to be equal.

SRJ vs. ANSI Flanges

Nominal Pipe Diameter Pipe O/D
SRJ Diameter
ANSI 900 LB Dia
Nominal Pipe Diameter Pipe O/D
SRJ Weight
ANSI 900 LB Dia
35 lbs
125 lbs
175 lbs
415 lbs
480 lbs
767 lbs

Snap Ring Joint Limited, Le Quai House, Le Quai D'Auvergne, La Collette, St Helier, JE2 3TN
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