Maximum Pressure for HX Tube Cleaning

[pc007]

I have a small u-tube exchanger with 1" x .065 wall tubes, which is severely plugged. I had a cleaning company take a look at it and give me an estimate on pressure washing it, and their proposal mentioned a 20ksi pump. That's the max capacity of the machine, so I'm not sure what pressure they actually planned to clean at. Before I confirm with them, I'm wonderind how I can determine a maximum pressure for jet-washing the tubes without damaging them. Is there any engineering basis to determine the highest safe impact pressure for mechanical cleaning? The tubes are SA-213 Gr. T11.

Thanks in advance!

 

[rmw]

Is this the cleaning company's maiden voyage, or have they been at this for a while? Assuming the latter, why do you mistrust their judgement. But since you do, do they have a customer reference list where they can provide a name and phone number for you to contact where they did similar work and/or used similar pressures.

If it is the former, can them and find someone in the latter category. Cleaning Hx's with hydroblasting techniques isn't rocket science and there are several companys out there really good at this craft.

rmw