Posted By Chris Pollington
Hi Clive
Having bought one for home use, I have noticed that it is stamped on the lance itself as a maximum safe pressure, This is much higher than the maximum working pressure of the washer unit.
If you have bought it as a set the manufacturer should ensure that it is matched with the unit.
If you are after information on the maximum legal pressure you can use through any lance system then I guess it is down to risk assessment and the maximum would be that which is safe under the circumstances.

I hope this is of some use
Chris.