Boshart Industries relief valves are recommended for all cold water system installations to protect against damage to piping and pressure tanks. Field adjustments are not recommended for these relief valves. Any changes made to the pre-set pressure is entirely at the risk of the person(s)/company who make the adjustment. Relief valves must be installed so that they drain to a floor drain, sump or other safe location with an air break. If an outlet pipe is used then it must be at least the same diameter as the relief valve outlet. Boshart Industries Relief Valve, Lead Free Standard, Series: RVNB-NL Series, 1/2 in Nominal, MNPT x FNPT End Style, 100 psi Pressure, Up to 140 deg F, Media: Cold Water, Spring Actuator, Brass Body, NBR/304 Stainless Steel/Brass Trim, 1.44 in L x 1.02 in W x 2.45 in H, Import