Isolate A Line On A Live System – AOGV

The Add On Gate Valve(AOGV) lets you isolate at any flanged connection in your system even while it’s under full pressure by combining many specialty services into one creative device.The AOGV comes from a Norwegian company based in Stavanger, Norway, that’s been around since 1987.

It is placed over top of the flange where it takes the bolts out, contains the pipe medium, and inserts a spade into the pipe and locks it in place.

It separates the 2 flanges with its flange spreading system, then inserts a spade into the pipe. It also acts as a leak containment device while it removes the bolts from the flange.

And all this is done while the system is under full pressure.

So with the AOGV, you get to avoid the time consuming, expensive process of draining the system.

No isolation point required. 

Where Did It Come From?

Kjetil Aamodt(the engineer behind the AOGV) noticed that specialty services including freeze plugs or hot tapping served the purpose of getting the line into a position where you can safely unbolt the flange.

He wanted to skip this process, so he asked, “How can I skip to the end and just unbolt the flange?”

He wanted a device that would allow the user to save money by not draining the system which also saves a ton of time.

The first application for the Add On Gate Valve was for the isolation of a heat exchanger that didn’t have a usable isolation point.

Right now, there are 2 inch through 24 inch applications that the AOGV can service, with high pressure applications performing up to #1500 rated.

Why Use It?

When it comes to the reasons to use the AOGV, consider the value of not having to shutdown in order to perform a repair.

When 1 day of lost production can mean millions of dollars for a facility, being able to bring in this tool to perform the isolation provides a ton of value.

There’s also the fact that if you’re performing work at -160 degrees celsius, or working at 200 degrees celsius, elastomer type line stops may not work very well.

With the AOGV, this problem disappears because it is simply a tool that inserts the blind into the pipe for isolation that is unaffected by temperatures.

No draining. No degassing. No cleaning.

This means you can perform the work outside of your regular shutdown. You get to free up your shutdown time to focus on other tasks.

How Is It Secured?

The Add On Gate Valve isn’t something that you can lift off the plant floor and place on the piping yourself.

It is made up of a number of components, and depending on the AOGV for your application, it can range from hundreds of kilograms up to 10 tonnes or more. Fortunately, a secure rigging system is part of the project in using an AOGV.

The AOGV sits on the piping it seals and activates on the piping, but it’s always in a rigged situation so that the load is supported externally.

Plus, throughout the process as it’s being installed, there are verifications performed to make sure it’s sealing properly including a hydro test that tests 110% or more of the actual internal system pressure.

And the AOGV meets code. It complies with ASME VIII standards.

In Conclusion

The AOGV lets you isolate your system at any flanged connection without draining, cleaning, or degassing…

So that you can make your repair without interrupting service and losing a ton of money in lost production.

It’s 100% safe, complies to code, and uses the most advanced scanning technology to make sure that the AOGV used for your situation is a 100% perfect fit.


Whenever you’re ready, here are a few ways we can help:

1. Discover a high quality pipe repair technology that is applied without hot work and provides you price flexibility based on how long you want it to last.
Composite Repair is great for making it until your next turnaround. Click here.

2. Looking for a way to isolate a line without hot work and shutting down?
Discover the Add On Gate Valve, a self contained tool that inserts a spade into any flange. Click here.

3. Learn how Forge Bonding, if it had been around, could have saved up to 60 lives or more.
It’s a hot work alternative that puts worker safety first. Click here.

4. Install a flange in 15 minutes without sparks or heat so that you can minimize impact on production and save money by requiring less costly labor.
Quickflange reduces installation time by up to 80%. Click here.

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