2 replies to this topic

[ankur2061]

Hi Friends

I want to know whether any guidlines are available for pipe specification breaks from process view point.

These could be for transition from high to low pressures, very occassionally from high temperature to low temperature and between corrosive and non corrosive environments.

If there are illustrative diagrams showing specification breaks, that would be even more helpful.

Looking forward to hearing from some of you experts.

cheers
ankur2061

[djack77494]

ankur,
I know of no general purpose guidlines for locating pipe specification breaks. Many companies do have guyidelines which they developed in-house. Typically, these guidelines are just an application of common sense and conservative design practices. For example, when transitioning from high to low pressure, tend to maintain the higher pressure spec through the furthest downstream valve(s) that could be closed, leading to development of the higher pressure. Similar for high temperature to low temperature situations and for corrosive and non corrosive environments. In simple terms, design for the most severe set of conditions that can be "seen" in any particular section of your piping system.

Of course, sometimes the more severe service is in the downstream piping, say for example, if you're adding a corrosive stream to a non-corrosive stream. In cases such as that, I would tend to move upstream from the point of mixing and add a check valve. The check valve then delineates between a non-corrosive upstream system and a corrosive downstream system. Always taking a conservative approach, consider the check valve to be in corrosive service.
HTH,
Doug

[praksyss]

hello everyone,

I m Pratik from India woking with Engineering Consultants in Western region i need help in prepartaion of Piping specification for Water lines with Sludge,and scale as its impurities please suggest me, i have some inputs and are as follows:-
Basic Piping material - carbon steel
max pressure - 16 kgf/cm2.
Temp-50 deg.c
Pipe size from 25 NB to 700 NB.

please help me with some basic formats of PMS..

Thanks
Pratik