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Caesar II Anchor blocks

Caesar II Anchor blocks

Caesar II Anchor blocks

(OP)
Hi
We performed the flexibility and stress analysis of a buried pipeline:
1. Caesar II not considered a safety factor in the determination of the anchor blocks left to the judgment of the specialist to use safety factor?
2. It is suitable to average force between the anchorage blocks obtained in Caesar II and PENG's formulates to design the anchorage blocks?
3. It is correct to place anchor blocks launcher outlet, receiver inlet and before and after the main line valve?

The pipeline properties are:
1. Pipe API 5L X65, 18" OD X 0.406" w.t., P = 1350 psig, T = 180 ºF, temperature of construction 75 ºF, fluid multiphase.
The force of anchor block calculate is 600000 lbf.
2. Pipe API 5L X65, 24" OD X 0.5" w.t., P = 1350 psig, T = 180 ºF, temperature of construction 75 ºF fluid multiphase.
The force of anchor block calculate is 1000000 lbf.

Thank!

RE: Caesar II Anchor blocks

chrism 1979, if you look a little further down the first page on this forum you will see a similar question about anchor blocks, which you should read firat and also search anchor blocks within this site as this is a common question.

1) Caesar just gives you the force applied to an ideal anchor. It is up to the designer to decide the FOS of the anchor.
2) I don't uderstand your question but maybe that's me. You only want one anchor block, if that (I normally try and avoid them like the plague as they are nothing but trouble), but if you have two in a short distance you'll break the pipeline.
3) It is common to see anchor blocks on the incoming and outgoing pipeline on the last buried bit of the pipeline which reduces the forces / movement on the pig trap, but you don't put them around a valve. It is much better to try and allow the pig trap to move the relatively small amount required to alleviate the thermal expansion or route the pipelines in a Z shape as they come close to the plant. When you work out how big the blocks needs to be to resist these huge forces ofr only a few inches of pipeline movement, you may see why we try and design them out...

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

RE: Caesar II Anchor blocks

what lil'bro said.
It is not appropriate to average pipe forces imparted to an anchor block.

Independent events are seldomly independent.

RE: Caesar II Anchor blocks

Sorry, not too much time last night to answer more completely.

Choose a fully rigid "Peng" anchor (using very high, infinite?, spring resistance), or design a "Drag" anchor, perhaps with a very much lower bilineal spring resistance, and model that with Caesar. An average between both methods might be justified by selecting the appropriate spring constants and designing the anchor block to mimic that by choice of dimensions, orientation and surrounding backfill, or vice versa.

Best advice is to avoid an anchor block entirely. There usually is no equipment placed so close to a pipeline that can't accept a relatively large movement. If there is critical equipment there, that's where things got messed up. Move it! You can mount a launcher on a skid with slotted foundation anchor bolt holes to accept a relatively great movement. Design attaching piping flexible enough to accept that movement and you won't need an anchor block at all.

The only reason most people still use anchor blocks today is that their project is located somewhere in the Mideast, where anchor blocks are required by many operator specifications, and their pipe stress program needs an anchor somewhere for the model to work, so the program jockey decides to add 500 tonnes of concrete to provide it with a fully rigid anchor, often according to the client's specs. The client doesn't know any better, he's just following his own specs, and the contractor likes to make easy money by digging a big hole and dumping 500 tonnes of concrete into the sand. Everybody's happy ... as clams. I hope the pun wasn't missed.

Independent events are seldomly independent.

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