Q & A > Question Details
There is a chilling water package that chilled water by use of propane refrigerant cycle. unfortunately propane cycle is polluted by caustic and we decided to wash the lines and equipment. I want to know, is washing with water or low pressure steam is harmful for this?
24/05/2011 A: Tajammal Hussain, OMV Exploration & Production GmbH, Tajammal.Hussain@uep.com.pk
Flushing with even low pressure steam is not recommended. Best solution is to flush system with Demineralized water. But before flushing give Demineralized water a retention time of at least 1 hr in piping/system. Repeat the above step until you get neutral pH. Demineralized water is highly recommended in order to avoid contamination in piping system which may lead to corrosion & pressure drop.
25/04/2011 A: keith bowers, B and B Consulting, kebowers47@gmail.com
Sodium hydroxide (caustic) is easily removed with water. Just flush until exit water pH drops to that of wash water. Then dry out the system and return to service.
25/04/2011 A: Marcello Ferrara, ITW SrL, mferrara@itw.it
The use of LPS could be harmful in case the operating conditions should exceed the materials' specifications of the refrigerant cycle. Water washing should be safer. To better remove the hydrocarbons and foulant from the loop, the injection of one of our patented chemicals will help in improving cleaning results and reduce cleaning time.
25/04/2011 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
Excessive temperature from steam could lead to caustic embrittlement/stress corrosion cracking of carbon steel. Strongly advise against use of steam unless you have a resistant alloy or the carbon steel has been post weld heat treated.
Flushing with water should remove any caustic. You will want to make sure that you get the system dry after the flush; otherwise, the flashing propane will cause any residual water to freeze, which could plug the system.
25/04/2011 A: SUNDEEP GUPTA, PETROCHEMICAL INDUSTRIES COMPANY, sundeep_gupta@pic.com.kw
Steaming will be of little use. You need to flush the system with water and thereafter you will need to purge it with Air, and later on with low pressure Nitrogen. It is important to remove all moisture from the system before you recommission it.
At the final stage you will need to check the dew point of Nitrogen from the exit point for moisture content. If dew point is adequately low (I guess it is -30C), will indicate a moisture free state of the system.