... work under presure for long time,advanced testing equipment to ensure thye quality,6.Packing:Wooden box ,sea- ... or as customers request.7.Delivery time:30 to 60 days after we signed SALES CONTRACT.8.Port of ... height of the heater may vary from 30 to 50m.Before the 1960s,cracking tubes were rranged in ... horizontal rows in a radiant chamber,leading to low ethylene capcity(20,000 mta,metric tonnes ...