Surge Mapping

[tika5828]

A vendor of Gas Turbine Compressor does not reccommend to do a Surge Mapping during Commissioning on our project. They said the reason is because:
"It all depends on how you can manipulate the production at site. You can change volumes and pressures to check the maps, but to perform a surge test, you must be able to manipulate suction and discharge valves. It is not something that we recommend."
During 15-year operation using this products, our company never did a surge mapping, since the Vendor did not reccommend it. While our Rotating Engineer insists to have Surge Mapping. What is your opinion?

Thanks.

 

[LittleInch]

I'm surprised you've not had responses to this, but I'm with the vendor. He has provided you with a surge map, getting it wrong could damage your machine. Why do you want to risk it?. You need to try and test at the required performance duty, but I see no value other than curiosity in proving a negative with respect to the surge limit. The risk far out weighs the value of the test in my opinion.

It is highly unlikely that you have high quality control valves on both inlet and discharge to provide the required variation in pressure and flow so would end up using ball valves or gate valves in manual probably wrecking them as well....

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[rotw]

What do you mean by surge map?
Do you mean performance curves indicating the surge line at the different operating conditions ?

Question to the OP: did you order a performance test type 1 or/and 2 for this machine before commissionning at site?

 

[elbrownos]

Vendor surge parameters are usually set very conservatively. There can be a lot to be gained (in terms of available operating range) by surge testing.
We prefer to throttle on the suction but it is also possible to throttle the discharge. I don't know why you'd need to do both at the same time.
Ball valves are fine.