Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Offshore structure parts 2

Status
Not open for further replies.
Replies continue below

Recommended for you

Sort by date Sort by votes
Thank you.

1 "SW",or "NE" (or whatever direction, or use an "A-1", "B-2" designation) Jacket Leg, Splash Zone,
2 Not sure what that is. May be,
"Stub" "SW", or "A-2" Jacket Leg, Splash Zone
3 "SW", or "A-2" Lower Deck Column, Elevation +XX.XX
4 "SW", or "B-2" Stabbing Point Flange, , Elevation +XX.XX
5 "SW", or "B-2" Lower to Upper Deck Column Joint, Elevation +XX.XX
6 Not sure what that is. May be
Jib Crane Mast Extension Joint

 
Upvote 0 Downvote
Item 2 is quite odd - might have been something left from either the jacket installation or the topside installation. Or maybe a protection for vessels moored to it? Did they fill the legs with concrete or grout after the topsides were installed?

6 - Some sort of collar? - difficult to see.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
Thank you 153-44 & Little Inch for the replies.

All the 4 legs has item no 2. I too think it has been something left after installation. The legs seem to be filled with concrete.
I have posted the picture of item no 6. It looks like some rubber sleeve around the support column on the loading arm.

 
Upvote 0 Downvote
That makes sense. No 2 is a concrete fill line for use after they transported the jacket to site and put it on the seabed. then they poured concrete it in to weigh it down and give it a bit more strength and stop seawater corroding it from the inside.

No 6 is a rubber collar that should be higher up - you can see the gap further up. It is designed so that when the crane jib moves around, it cushions the main support leg from damage as the half shell hits it. But it's fallen down.

So its a rubber protection sleeve.

But it needs to be fixed back in place.

That second photo 3580 shows it much better. The crane jib can rotate 180 degrees, but the position stop is supposed to hit the protection sleeve. on the other photo you can see the metal clamp on the bottom is broken.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
OK. Usually they do that before topside is in place, stabbing the pile down through the jacket, then grouting only at the pile jacket near the seabed. This is probably very shallow water and the pile top is very close to the waterline, or even a bit above.
 
Upvote 0 Downvote
Thank you. It resembles the flare stack igniter as in the link you have sent. Anyways I have attached a document with clear image.
And what was that vertical post in the previous document I had attached?
 
 https://files.engineering.com/getfile.aspx?folder=c3e9c499-23a4-47e2-b838-783409a4fec5&file=New_Microsoft_Word_Document_(2).pdf
Upvote 0 Downvote
I think it might be a pilot flare. I dont know about the details of flare systems. Sometimes they keep a small gas fire continuously lit adjacent to the main flare, so any large quantity of gas arriving suddenly at a flare tip not burning is ignited immediately. That may be the pilot flare stack.

 
Upvote 0 Downvote
Thanks a lot 1503-44.
Thank you again for your information regarding the flare and pilots.
 
Upvote 0 Downvote
I don't think that big pipe is actually a flare - more like a vent line - you don't usually see then at an angle like that.

I think those three little prongs are measuring heat in case the vent ignites or measuring it to make sure it hasn't gone out. You should find them on a P&ID of the vent/flare system which should tell you what these are supposed to be.

The little line looks like a small diameter cold vent to me.

The long pipe thing looks like a lightening rod to me as well, but I'm glad I will never climb up such a thin vertical pipe....

But mr 44 could be also dead right about the flare stuff.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
I think it might be some kind of flare monitor. They wouldn't function too well for very long if they were close.

 
Upvote 0 Downvote
It's just I've never seen a flare which wasn't a vertical pipe with a horizontal end on it.

This thing is off a 45 degree elbow, then cut at 45 degrees to have vertical face. Looks like a vent stack to me.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Upvote 0 Downvote
Thank you 1503-44 & LittleInch for your valuable inputs.

I agree with LittleInch regarding this. This is a vent as there is no black soot around the pipes which gets deposited on the external surface of pipes due to flaring. The small pipe was supposed to have a hat like structure on top which has corroded away which is not required in a pilot burner.

I also think the vertical post is for lightening arrestor.
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

Bubik
  • Locked
  • Question
Carrier Shift from Structural (buildings) to Offshore Structural Eng.
Replies
2
Views
43
gerhardl
gerhardl
Gabriel Pedro
  • Question
Design of gravity based structures- reinforced concrete design
Replies
0
Views
147
Gabriel Pedro
Gabriel Pedro
Inspector89
  • Locked
  • Question
Jacket Structure 1
Replies
3
Views
51
LittleInch
LittleInch
Althalus
  • Locked
  • Question
Transportation Loads for offshore unit
Replies
0
Views
31
Althalus
Althalus
Tasutasu
  • Locked
  • Question
Type 3.2 certificate required by ABS rule [Offshore structure]
Replies
1
Views
40
gerhardl
gerhardl

Part and Inventory Search

Sponsor

Back
Top