Hello guys, i work at a fertilizer plant, and as i go over the P&ID's looking for the schedule numbers of pipes existing in the plant, it seems that i can't find it in the drawings. I looked for the data sheets of the valves that are in the plant and found out that the valves has corresponding schedule nos. Is it safe to assume that the pipings and valves have the same schedule nos, provided that they exist in one system?

Mostly the linenumbers include the pipespec. and in the pipespec. You can find the material of pipes and fittings.
Please explain more about that company tht don´t use pipespecs.

Otherwise, look at the iso´s.

JessCalizar,

Check the legends and abbreviations section if there is one for your P&IDs. That should list how the piping specs are called out. From there, you should be able to get the pipe schedule from the piping specs. For example, the company I work for uses piping notation like 2" HPS-E1-HC where the 2" is line size, HPS means high pressure (200 PSI) steam, E1 is the piping spec class, which according to the legends and abbreviations is 300# RF rating in carbon steel, and the HC means the pipe is insulated for heat conservation. From my piping specifications (from the maintenance supervisor, and also the corporate website), the E1 specification refers to PIP PN03CS1S02, which correlates to STD (sched 40) pipe for a 2" line. If the line had been 1", it should be XS (sched 80) per the standard. Check with your maintenance group, mechanical integrity engineer, or corporate engineering to see what piping specs you use and also for the abbreviation list for your P&IDs. Hope this helps.

Regards,

Matt

Quality, quantity, cost. Pick two.

JessCalizar,

I agree with MatthewL. The schedule number should be indicated in the P&ID. The "Line Identification Number" in the legend sheet should indicate what you need.

Regards,

Christopher Kenneth Choa

In my 33 years with 3 companies working with many EPC firms, they all used pipe specs on P&IDs. A pipe spec can cover several schedule numbers of pipe. I've never seen schedule number on a P&ID.

Good luck,
Latexman

Latexman is correct. The typical practice is to identify a pipe spec for each line. The pipe spec may be limited by a flange or fitting class, and hence may have different pipe schedules at different sizes.

I agree with the last two posts. You have to find the pipe spec identifier on the P&ID. Then use that pipe spec identifier to find the actual pipe spec that shows the pipe materials, schedules, fittings, flanges, and sometimes valves for that type of pipe.

A good guess is schedule 40 for most CS pipe and 10S for most SS pipe in the fertilizer plant. Unless you are in acid service which may increase wall thicknesses for corrosion resistance.

Can you be more specific about the fluid media?

Good luck.

Thanks guys,

I am looking at a pipeline that carries sulfuric acid, as of now, i have not seen the sched no. specified in the P&ID, but i;ve seen the pipe spec not for the pipe itself but for the valves, is it safe to say that the sched no. (thickness) of the valves on the pipeline corresponds to the sched no. of the pipeline itself?

NO, that is NOT a safe assumption! Valves have flange classes and body ratings- they do not have "schedules"!

You need to find the pipe specifications this piping was originally designed to, before you make any modifications. Sulphuric acid is a service where velocity is critically important and corrosion allowance is essential. Failures have serious consequences.

If the information is not available to determine the original design intent, any modifications require re-engineering by competent people knowledgeable in this service to ensure that they're safe.

I would clarify what GHartman said somewhat. Schedule 40 and standard wall are synomymous in pipe schedules up to 10" pipe. Above that Schedule 40 pipe continues to have ever increasingly heavier walls than std wall which is 0.375 in 12" pipe and above. Make sure what you have.

rmw