We have 2 pipelines one for water , one for oil.. these lines enter to a power plant .What is the codes for these lines inside and outside plant ?

ASME B31.1 POWER PLANT PIPING

Outside pipeline : AWWA for water pipeline

                             ASME B31.4 for oil pipeline

Inside piping: ASME B31.1 for both of which

Sir

It's a really very good question & these kind of scopes are often confusing in contract documents also. But, simplifying this, ASME B31.3 shall be used for water piping & ASME B31.1 shall be for boiler piping. the scope of ASME B31.3 shall be limited upto the block valve. In case, if the block valve is inside the boiler , then after block valve the code shall be ASME B31.1. In that case, even the material of valve body, spool pipe & Matching flanges shall be of ASME B31.1. Matching of these two code shall be preferred first for this kind of particular applications.