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How is BoltEx® Designed and Tested for Safe and Reliable Hot Bolting?

WHAT is BoltEx®?

The SRJ BoltEx® flange clamp retains compression on the gasket between flange faces whilst stud bolts are exchanged one by one in a process known as hot bolting. It is also known as single stud replacement, line bolting or bolt replacement.

BoltEx® is designed to ensure the flange gasket is not overloaded using its Gasket Protection System (GPS).


Is BoltEx® safe to use?

BoltEx® has been designed using advanced engineering methods to ensure its suitability for hot bolting. BoltEx® has also been tested using loading that simulates scenarios far above those experienced in the field. The BoltEx® design is independently verified by Bureau Veritas.



HOW did SRJ design BoltEx®?

SRJ engineers have spent years refining the design of BoltEx® using Finite Element Analysis (FEA) to ensure that even in the most extreme load cases, each BoltEx® unit design has ample strength capacity to handle the job at hand.


We model the most demanding scenario of the flange pressurised to 1.5 x design pressure with all flange bolts removed. BoltEx® retains the flange gasket compression to ensure no process fluid leakage, even in this extreme case. It achieves this without ever overloading the flange gasket.


Our in-house engineering capability also allows SRJ to design non-standard solutions for our clients.



HOW do you test BoltEx®?

SRJ work with an independent test facility close to our manufacturer to ensure that we can demonstrate that BoltEx® performs as the design intended.


We conduct operational testing that simulates the hot bolting process in the test environment and strength testing that takes the flange design to the limit but remains well within the capacity of the BoltEx® design. In all test cases, no loss of containment has been experienced, and no gasket has been crushed or damaged.



WHAT is the track record for BoltEx®?

BoltEx® has been used extensively globally in onshore and offshore environments. It has proven that the work put into the design and testing has produced a solution usable in the field by regular bolting teams.



We constantly seek and receive feedback from our clients, allowing us to adapt design aspects to ensure usability without compromising strength or functionality.



Those who buy BoltEx® like the flexibility of using it on their own terms with their regular people and dispensing with the need for specialist hot bolting service providers.


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