Valve (manual) Ratings? on P&ID

There must be a legend to that P&ID drawing, may be located at the drawing itself or (as in many cases) there is an attached legend. Look for the full specifications of the project.

No legend or key is given. I checked both the valve symbol rating on P&ID and the actual valve size on site. Both are same.

For e.g a GA050 gate valve on P&ID is 1/2 in in size on site. Similary BAFF0406 on P&ID is 4" in size. GA075S is 3/4 in size.

I think the figures do represent the actual valve size.

Anyone?

The purpose of a drawing is to communicate.

If the legend is not available, then the communication has failed.

Go back to the originator of the drawing and obtain a copy of the legend!

Unfortunately we are all going to be guessing in the dark because there are all sorts of things that we have seen alongside valves on P & IDs and only your particular legend will resolve this for sure

Initially it looks like a description (Ga - Gate, NV - Needle)

Size looks a fair description for the next set of digits

The FF could be Flat Face (All flanges will be assumed to be Raised Face unless noted)

CSO - Car Sealed Open

If you think the size is what is intended then go with it. I would be surprised because I would take the size of a valve from the line size which should be given and on the P & IDs I am working with the different valves have different symbols so there is no need for a designation to show this. Perhaps the number includes something for flange rating?

I have seen (and hate doing it) every single valve get a tag number but they are sequential and it looks as though you only have numbers that are multiples of 25.

So all sorts of things are possible and in you position I think I would probably just ignore the number because you know what the valve type is and what the size is.

As a piping designer and creator of many P&IDs, i agree with the postings.

Project P&IDs should have a legend. Currently I am working at a facility, and they have added valve codes for replacement and/or purchasing similar to that of a speciality number. There is no reference to a legend. One needs to contact a senior type at the facility to educate yourself to the sites standards.

I deal with P&IDs from differnet places on a regular basis. When numbers are indicated beside the instrument or valve it is typically a tag number so the valve or instrument can be identified. These numbers are also located on the bill of materials, so you can identify exactly what the valve is, i.e manufactured, rated pressure temperature and materials.