teesan,
This is not something that anybody on the forum can provide you an answer with.
You are making the cardinal mistake of asking people who have absolutely no knowledge of the make, capacity and configuration (no. of cylinders / valves) etc. of your 2-stage reciprocating compressor.
In the 'Cheresources' forums this has been explained numerous times that the first place to look for specific information or data for specific machinery is in the catalogs and manuals of the machinery or equipment manufacturer. If, for any reason, these documents are not available with you, the OEM (Original Equipment Manufacturer) needs to be contacted and the questions / issues related to the equipment be resolved with him.
Let us assume that you get an answer from one of the forum members based on the information you have provided, that the DM water specific consumption should be 2 m3/h. Will you take this at face value? The forum can't and never will be a substitute for specific data related to machinery items and the go-to place will always be the machinery manufacturer.
Hope you understand.
Regards,
Ankur