Dears, I have a serious problem, the marine line that supplies water for cooling to the power plant I work in is about to block. Marine scales is the problem, it is a new issue to me. Any help is appreciated

Kahtib,

I will assume that it is sea water that is the medium.
I will also assume (pl. confirm) that there are inlet trash racks and filters to stop large floating items such as wood pieces, algae colonies etc from entering the pipe. You do not mention anything about pumping; are there pumps at the sea end or land end?
The odds are that the fouling is by barnacles and other sea animals. You should have some evidence of these in your Condensers. generally, these enter the pipe when they are tiny, passing therough the smallest mesh of filters. They attach themselves to the walls and grow by feeding on passing nutrients.
If the above hypothesis is correct, then
- You have potentially a serious problem of the pipe collapsing/ breaking if pumps are in use.
- If you try to remove the deposits by e.g. hydro-jetting, large volumes of smashed barnacles may clog up downstream piping and Condesers. This can shut your Plant down for long periods.

Get some data to identify what exactly is going on inside the pipe. You may have some major expenditure in store.

K. Kahtib,

I hope you have solved your problem meanwhile. Considering the name of the forum, "HDPE marine line blockage", may I assume that this is the material of the clogged pipe? Which is the diameter and length? Did you make periodic inspections, with divers or ROV's? (Remote Operated Vehicles).
It is claimed that on HDPE no biofouling or marine growth will occur. Has anyone a different experience?
For a new project in Chile, with a large diameter (1800 mm) and long seawater HDPE intake pipe on the sea floor, we are just now discussing with the contractor the need of installing manholes to facilitate inspection and provide safe diver access (one manhole every 150 to 200 meter). His opinion is that manholes are not required for HDPE pipes. Any comment would be welcome.
There are some remotely operated cleaning systems, but we have not found any with operational experience for our diameter. Does anyone have experience with these systems?
Any information and comment would be appreciated.