Underwater Safety Valve

[booob630]

I would like to learn what's difference on underwater safety valve (USV), surface safety valve (SSV), sub-surface safety valve (SSSV) and subsea valve. I am working on a design for underwater safety valve to follow up API 6A application, how to set up the depth of water? if the all calculation will be same as surface safety valve (SSV)?

Any assistance would be appreciated.

Thanks in advance.

 

[MortenA]

Ssv and sssv are in the Well and subsea is in a pipeline. I have not heard about USV before

 

[SJones]

USV/SSV is defined in Spec 6A and Spec 6AV1. SSSV is defined in Spec 14A.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[LittleInch]

I hadn't come accross the term USV before but as always S Jones is correct - it's defined in 6A, often as SSV/USV.

SSV is Surface safety Valve which if the tree is underwater could also be called an USV.

SSSV is also known as "downhole safety" and is inside the well bore itself. So it doesn't care whether the well is above or below sea level

Subsea valve is just any valve which is below sea level.

How to set up depth of water - Up to you. Where is the valve going to be in the world? Which markets do you want to supply. Some areas are relatively shallow (<100m) some up to commonly 3-400m and some up to 2000m.

API 6A seems to have made a distinction between a wellhead safety valve above water (SSV) and one on a well below water (USV). But they do the same job. Many calculations will be the same.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[booob630]

Thank you very much LittleInch.

If I consider this USV will working under a shallow (<100m), if I need to calculate the external water pressure? In the addition if a hydraulic actuator is available?