New gas pipeline pressure alarm setting

[Julio8287]

Hi everybody:

34", 408 km, natural gas pipeline, with min. MAOP design and min MAOP hydrotest as data, I would like to know which is the best way to setting my scada alarms for high, high high, low and low low pressure?.

Thanks in advance.

 

[zdas04]

Depends on your RTU, but most of them today use screen input. Some of the older ones required a screw driver.

I bet that rather than asking how to set the alarms, you were really asking how do you determine appropriate set points for those alarms. For that one you are probably on your own. Each system is different and the way the equipment interacts is different. Alarms or kills need to be set at values that minimise total risk. A low low pipeline pressure alarm would probably be interpreted as a major rupture, but it could also be a loss of supply. Low alarms are usually set to protect some piece of equipment like a compressor that has temperature problems when the compression ratios get too high. etc. Knowing the MAOP is not a lot of help in determining operational setpoints since normal operation should try to stay away from any PSV setting.

David

 

[BigInch]

Obviously high alarms can be set to comply with allowable transient pressures.

Minimums are best set by an operational simulation of each mode of operation you might have, first at near minimum pressures when in steady state and then for the lowest pressures seen when transitioning between one mode of operation to another.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit

http://www.youtube.com/watch?v=hpiIWMWWVco

http://virtualpipeline.spaces.liv

 

[Julio8287]

David & Binginch

Thanks for their answers.

Regards

Julio