Inquiry (采购产品): vacuum relief valves am using a nash liquid ring vac pump capable of 450 scfm @ 25"hg need a pop off valve to protect against dead head at 20 or 21"hg on a 4 inch pipe **** Hidden Message ***** Ray Griffis 1200 River Road Fulton, CA 95439 USA Company: Fulton Processors Inc Title: Maint. Eng Phone: 707 217 4203 Fax: 707 528 2363 E-mail: john@fultonvalley.com **** Hidden Message ***** john@fultonvalley.com