Bell & Gossett model FB38 1/2" female by female NPT brass reducing valve for low pressure hydronic systems with their check valve and strainer factory set to 12 psi. This valve has an adjustable range of 10-25 psi. This model also features a "fast-fill" handle which opens the valve full open for faster filling of the hydronic system.Specifications:1/2" FNPT ConnectionsFactory Set @ 12 PSIAdjustable Pressure Range 10-25 PSIHas Fast Fill LeverThese low pressure reducing valves are equipped with a low inlet pressure check valve and removable strainer.Replaces Bell & Gossett FB-8, 110110 and 110111Also Replaces Sid Harvey B138-4R