The RV-2000 series regulating valve can also be used as a relief valve. Designed to provide system pressure relief for #1 through #6 fuel oil grades and for rated pressure ranges of 0 to 500 psi. @ 150 gph or less. The following adjustment ranges are available. 100-330 psi. use RV-2002,  10-25 psi. use RV-2003,  40-110 psi. use RV-2004. Pipe as configured below.