Inquiry (采购产品): Auto closing Valve ( 2 range ) I am wondering if there is a valve that will automatically close after liquid stops flowing and air starts. If off loading a railcar by air. I understand that there is a valve like this that is used for anhydrious ammonium service. **** Hidden Message ***** Vance McVicker PO Box 29080 Portand, OR 97296-9080 USA Company: WD Nelson Construction, Inc. Phone: 503.781.1979 Fax: 503.224.3360 E-mail: wdnc@msn.com **** Hidden Message ***** wdnc@msn.com