Subsea valve assignment

Read EP GP 62-01-1 and GSH-EN-SPE-78050 (See attachments). The former gives guidance on topsides and subsea valves whilst the latter is subsea specific Company supplier requirements.

Most subsea valves designs are derivatives of valves for topsides applications and therefore much of the technology is shared between the two. The subsea environment however requires valve designs to include specific features and technology to be able function correctly in a subsea production system over the life of the field.

1. You will note from reading the above referenced specifications that fewer valve types are recommended for subsea service. Discuss why this is the case?
2. Using the above referenced specifications and included drawings (Drawing 6 inch gate valve, Drawing 10 inch ball Valve operator and Drawing 10 inch ball valve) of subsea valves, compared to topside applications discuss:
   1. What additional design features are required for subsea valves and why are they required?
   2. Which design features, materials, testing scopes often require modification to suit subsea applications and why are they necessary?
   3. Are there any design features that are not desirable to have subsea and are required to be removed, if so why?