When you are working with that high of pressure, a perspex shield isn't going to offer suitable protection. You should look at building a dedicated pressure test bay with CCTV cameras so the operators are not exposed to any potential high pressure leaks. Has your risk assessment identified this as a high potential activity? Working with pressure even as low as 4psi can cause major injury. I used to work with a guy who stood to close to a piece of equipment being pressured to 5000psi. An incorrectly fitted hose went pop and hit him in the leg. He was in hospital for 6 months and was unable to walk that whole time. Ther last thing you want is for this to happen to one of your guys. You should also consider sending your operators on a pressure testing awareness course to highlight the dangers associated with this. I did this for the operators in a company i used to work for and it changed thier outlook for the better once they had seen the damage it can cause.

Mike following on from the PM I sent you here is another http://www.dennismac.co.uk/hands/hyd/index.html Please don't go to this web site if you are squeamish - It shows what happens when testing goes wrong