TurboCompressor Train Responsabilty 2

[wimple]

Hi

In case of turbocompressor trains (API617), I would ask for your insight to clarify the following :

1 - Single Source : Is this mean that Each equipment, Gas Turbine and Compressor, are both provided from the same Manufacturer. This leads Ipso Facto to Single Responsability.

2 - Not Single Source : In this case, Gas Turbine and Compressor shall be provided from different Manufacturer.

Train Responsability in case of Not Single Source supply : Shall one of the Manufacurer (compressor or Gas Turbine) always buy the other part of equipment from the other manufacturer and then take full train
responsability in face of the end user. Or do you forseen alternative scenario ?

So as per API, who has the train responsability? is it the compressor or the Gas Turbine Manufacturer? And eventually, how this is related to String test if it is performed?

Any reference to API codes/paragraph would be appreciated

Thanks in advance
Regards
Wimple

 

[milltir]

My stock answer to questions like this is "it depends".

Often the practice in Europe is to make the compressor vendor prime (but not always) whereas in the US the GT vendor is often prime (but again, not always). One party does need to take responsibility for the train and this can be done by placing the entire PO with say the compressor vendor and they buy the GT or the purchaser can buy both and pay one of the vendors (let us say the compressor vendor) a handling fee for taking train responsibility and managing the gas turbine sub order.

Who gets to be prime in my opinion depends on the vendors and the application - if it is a complicated 3 section duty then it might be better for the compressor vendor to be prime wheras for a pipeliner application the GT vendor might be more appropriate. Having said this other factors come into play though such as:
- string testing capabilities of either vendor
- is the purchaser is physically close to one of the vendors
- the purchaser has existing arrangements with one of the vendors

Like most things in life you weigh up many factors and pick the least bad option.

 

[rlewis]

Which vendor is prime often depends on commercial issues - i.e. what is the relative cost and complexity of the gas turbine vrs. the cost and complexity of the compressor. If the gas turbine cost is very high and the compressor relatively low, the compressor supplier may refuse to be prime or charge a very large adder for risk.

It is important to have one vendor as prime in order to ensure that the interface issues are properly addressed.

API addresses "unit responsibity" (1.8 in API-617) but does not address which vendor this is since as stated it is a commercial rather than a technical issue.

We have done many steam turbine drives with the compressor supplier as prime using another supplier's steam turbine driver even though the compressor manufacturer also had his own steam turbine line. It is thus possible to "mix and match" even where a vendor builds both driver and driven equipment.

 

[wimple]

Thanks All for your valuable answers
Best regards
Wimple