The vacuum responds to burn the knot carbonization the to spray the sand , it to have the degree of hardness high, anti- characteristics of violent wear and tear etc., applicably do to spray the sand the , water the sand to incise the and steel factory, hot power station...etc. the profession to use to spray the coal .Its life span is a common quality of 5-10 times.
All products can be produced as per your drawing.Standad size can be made as soon as you require