Drain liquid relief system for a subsea compressor and a method for draining the subsea compressor

A drain liquid relief system for a subsea compressor, comprising:

• a suction scrubber a drain storage tank for collecting drain liquid contaminating the compressor flow in the drain storage tank;
• an intermittently pressurizing device and a suction line connected to the bottom of the drain storage tank;
• wherein the suction scrubber is connected to the compressor suction nozzle and/or a compressor casing drain line, the suction scrubber being further connected, via a first check valve, to the drain storage tank for collecting the drain liquid in the drain storage tank, and
• wherein the intermittently pressurizing device is adapted to intermittently pressurize the drain storage tank to intermittently blow the drain liquid out of the drain storage tank through the suction line.

A method for draining a subsea compressor, comprising the steps:

• providing a drain liquid relief system, the drain liquid relief system comprising a suction scrubber and a drain storage tank for collecting drain liquid contaminating the compressor flow in the drain storage tank, as well as an intermittently pressurizing device and a suction line connected to the bottom of the drain storage tank, wherein the suction scrubber is connected to the compressor suction nozzle and/or a compressor casing drain line and is further connected, via a first check valve, to the drain storage tank for collecting the drain liquid in the drain storage tank, the intermittently pressurizing device being adapted to intermittently pressurize the drain storage tank in order to intermittently blow the drain liquid out of the drain storage tank through the suction line;
• continuously collecting drain liquid contaminating the compressor flow in the drain storage tank;
• and
• intermittently pressurizing of the drain storage tank by the intermittently pressurizing device, in order to intermittently blow the drain liquid out of the drain storage tank through the suction line.