BoltEx® - Bolt Exchange Flange Clamp
BoltEx® ensures flange integrity during the bolt replacement under pressure, also known as 'hot bolting'.
Proven to perform at 1.5 times the design pressure even with all flange bolts removed - BoltEx® presents a robust and effective solution for ensuring bolted joint integrity.
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Quick and safe to install
+ 1-2 installers
+ Available for sale
+ No damage or disturbance to gasket
+ Optimised design and weight for efficient installation and handling
Robust and versatile
+ Proven to perform at 1.5 times the design pressure with all flange bolts removed
+ Countersunk bolts for space restricted locations (e.g., near valves or bulkheads)
+ Open design allows better access to the bolt removing tools
+ Designed to be reusable multiple times
+ Can be left in place for an extended period of time preserving flange integrity
+ Eliminates the need for plant shutdown to rectify bolting anomalies
+ Prevents loss of containment on flanges
+ Extends asset lifetime and reduces maintenance costs
Innovative Gasket Protection System (GPS)
+ GPS prevents over-compression or release of sealing pressure of flange gasket
+ BoltEx® bolts are pre-loaded against the GPS; compression load on the gasket is maintained as the flange bolts are replaced
+ In case of flange bolt failure BoltEx® safely takes the load preserving joint integrity
Our customers use BoltEx® for enhancing Flange Management, shifting from a reactive "fire-fighting" approach to mitigating the bolting anomalies in a proactive and effective manner.
Installation & Hot Bolting
Here is a quick explanation of what each part of BoltEx® does using the colours in the 3D model above.
Use your mouse to grab BoltEx® and explore how it works for yourself - the mouse wheel will zoom in/out.
RED – The threaded clamp half of BoltEx® into which the Gasket Protection System (GPS) hollow spacers (blue) are screwed.
BLUE – The Gasket Protection System (GPS) hollow spacers screw into the threaded clamp (red) and protect the flange gasket from being overloaded.
YELLOW – The slotted clamp half allows BoltEx® to be installed from one side only, as the supplied BoltEx® studbolts/hex nuts (green) are prevented from rotating by the slotted retainer.
GREEN – The required studbolt fasteners are supplied with each BoltEx® and pass directly through the slotted clamp (yellow), the hollow spacer (blue) and the threaded clamp (red). These studbolts provide the compressive force on the gasket while the flange studbolts are being exchanged.
BLACK & GREY – The target flange and the studbolt fasteners to be replaced.
Is BoltEx® one size fits all?Each BoltEx® model is designed to fit a specific flange size and rating. Our standard range spans across multiple 4 and 8 bolt ASME/ANSI B16.5 flanges from ½” to 8”, and from 150# up to 1500# rating. Full details can be found here: BoltEx® Technical Datasheet. BoltEx® clamps to suit other flange sizes and ratings are available upon request.
How many people are required to perform bolt exchange using BoltEx®?Ideally two people are required to perform bolt exchange using BoltEx®, though for smaller units it is possible with one person.
What tools are required to install a BoltEx® clamp?BoltEx® can be installed with basic equipment that is readily available, namely: an adjustable spanner, a calibrated torque wrench and a socket set.
If the flange bolts cannot be removed, can BoltEx® be left in place?BoltEx® has been designed to also be used as a flange reinforcement device and can be left in-situ for a defined period as determined by an operational risk assessment.
Can BoltEx® clamps be used to change out bolts on connections that span orifices or line blinds?Extension kits are available for BoltEx® clamps to enable the clamps to bridge a larger gap between the flanges. These kits comprise longer fasteners and extension pieces for the GPS (gasket protection system).
When would BoltEx® flange clamps typically be used?The most common use of BoltEx® clamps is to facilitate the online replacement of corroded flange fasteners that have been identified via in-service inspection and reported as bolting “anomalies”. BoltEx® clamps enable these anomalies to be rectified under normal plant operating condition and thus in a timely manner. BoltEx® clamps are also often utilised before planned shutdowns to confirm that bolted flanged connections at key pressure isolation boundaries are in an acceptable condition and thus reduce the risk of any emergent problems occurring during the shutdown that may jeopardise planned activity sequences or the overall schedule.
What is the service life of a BoltEx® clamp?In regular use the service life of a BoltEx® clamp is typically 3 years.
Can SRJ provide a full hot bolting service?We work very closely with selected service partners globally to provide a full hot bolting service to asset operators when requested. We can analyse flange anomaly data and define work scopes and work packs as required to deliver a focused bolting anomaly rectification program for your asset.
What flange body materials can BoltEx® be used on?BoltEx® can be used on all metallic flanges. It can also be used on GRE flanges, though extension kits may be required to compensate for the thicker flanges.
Is BoltEx® suitable for non ASME/ANSI B16.5 flanges?Using our own in-house team, SRJ can design bespoke size BoltEx® clamps to suit other recognised standards.
What flange types can BoltEx® be used on?BoltEx® is designed to fit ASME/ANSI B16.5 RF, RTJ and FF flanges.
What is a BoltEx® flange clamp?BoltEx® flange clamps are designed to act as a safety barrier that enables safe exchange of the fasteners on bolted flanged connections whilst they remain pressurised - a practice which is commonly known as “hot bolting”. Since the exchange process is performed one fastener at a time this activity is alternatively referred to as “single stud replacement”.
How does it work and what are the key components of BoltEx®?BoltEx® comprises four clamp halves that are positioned around and on either side of the flange connection and bolted together. BoltEx® works by relieving the load from the flange bolts which allows these to be safely removed and replaced. The key component is the GPS (Gasket Protection System) which allows the load to be relieved from the flange bolts while preventing the gasket from being overloaded or crushed. BoltEx® requires only standard torquing tooling to operate.
Can BoltEx® be reused?Yes, BoltEx® is designed to be reused multiple times.
Are BoltEx® clamps supplied with any spare parts?BoltEx® clamps are shipped with spare spring pins, which are used to join the clamp halves together. We stock spares for the hollow spacers that comprise the GPS.
What training/qualifications are required to use BoltEx®?BoltEx® is designed to be used by individuals that are trained and competent with the torquing and replacement of bolts. SRJ provides an installation procedure, training pack and online assessment module to be undertaken by those holding a recognised flange bolting qualification. The online training takes around one hour to complete, and a certificate is provided to those that achieve the pass mark in the online assessment. SRJ recommends that personnel using BoltEx® have the recognised flange bolting qualification to a standard appropriate to their region e.g. EN, ASME, ECITB.
Has the BoltEx® design been tested or independently verified?BoltEx® has been strength tested to 1.5 times design pressure with all flange bolts removed. The design has also been independently verified by Bureau Veritas. A copy of the Independent Review Certificate can be provided on request.
What information does SRJ require to do a hot bolt scope assessment?We can work with the available information, as we recognise that not everyone has a fully populated flange register and/or anomaly register. We will work with your team to arrive at the most efficient solution given the available data to hand and we can help plug any data gaps along the way. We invite our customers to complete a BoltEx® Customer Enquiry Form that will help us get started.
How long does it take to perform bolt replacement using BoltEx®?The time taken for removal and replacement of flange bolts will vary dependent on flange condition and accessibility, bolt quantity, and condition of fasteners being replaced. Based on experience from use in the field over multiple assets, the average time taken for bolt replacement using BoltEx® is around one hour per flange.
Are manual handling aids required to install BoltEx® clamps?For the majority of BoltEx® clamps the individual parts weigh less than 10 kg, so for most uses manual handling aids are not required. All BoltEx® units incorporate suitable fixing locations for lanyards for safe handling to limit the risk of dropped objects if working at height.
Are BoltEx® clamps available for purchase or hire?BoltEx® is available for purchase as well as hire. It is typically more commercially viable for our customers to purchase BoltEx® and make it part of the standard toolbox for flange bolt management.
Where have BoltEx® clamps been used up to now?BoltEx® clamps have been used globally across a variety of different industries with supply arrangements tailored to the client e.g., sale or hire. Case studies can be provided on request.
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