"Stephen,
Do you have simulation facilities to load your stuff at 6000 PSI ?"

Basically, a high pressure chamber filled with the fluid that will be seen by the end application and with a means to pressurize at the rate that will be seen by the end application. If the rate is not critical, then a simple hand pump will do the job. Actually when we do this we find that the pressure is mostly a non-issue but the SIZE of the chamber is one hell of an issue. Even working with a design safety factor of 2 times the maximum pressure, the wall thickness and material choice become unwieldy pretty fast.

PS : Stephen, despite your warning not to post non-specific replies, I think I just did so. Sorry about that.

Raghu