API 617 (7th edition, I know there is newest) - Chapter 1, clause 5.3.2.1.3:
"If a performance test is specified, the vendor shall provide test data and curves when the test has been completed.
The surge points shall be shown on the performance curves."
Chapter 2, clause 4.3.3.1.1:
"The compressor shall be performance tested in accordance with ASME PTC 10-1997, ISO 5389 or other approved national standard. A minimum of five points, including surge and overload, shall be taken at normal speed. For variable-speed machines, additional points may be specified..."
In terms of practice, surge points established during performance testing (type II) can be used as basis for design of the control system. Based upon that, the controller parameters can be set on an preliminary basis which already improves upon predicted curves information. In general, but not always, a dedicated surge testing is done during commissioning/plant start-up to establish the surge line; the controller parameters can be tuned / frozen. I suppose this does NOT need to be part of the purchase order to compressor vendor. Surge testing, if not covered by company (buyer or contractor) standards, is a requirement that can be evaluated/coordinated together with the vendor services representative, the anti-surge system supplier and all the stakeholders (end-user and contractor).
