Bell & Gossett model FB38 brass pressure reducing valve with a 1/2" female x female NPT connection. These valves are for use in low pressure hydronic systems with a check valve and strainer that are factory set to 12 psi. They feature 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, and includes the connection nipple, nut, and washer.Specifications:1/2" FNPT X 1/2" MNPT Threaded Union ConnectionFactory Set @ 12 PSIAdjustable Pressure Range 10-25 PSIHas Fast Fill LeverReplaces Sid Harvey B138-12 & B138-12R