Specifications - City of Montpelier, Vermont

Title:Montpelier District HeatingCity of Montpelier, VT15055– Basic Piping Materials and MethodsIssue Date:September 28, 2012Page #:9 of 101. Pipe 2" and Smaller: Thread pipe with tapered pipe threads in accordancewith ANSI B2.1. Cut threads full and clean using sharp dies. Reamthreaded ends to remove burrs and restore full inside diameter. Applypipe joint sealant (Rectorseal No. 5) or Teflon tape suitable for the servicefor which the pipe is intended on the male threads at each joint and tightenjoint to leave not more than three threads exposed.2. Pipe Larger Than 2": Weld pipe joints in accordance with ASME Code for"Power Piping," B31.1 or “Building Services Piping” B31.9 as requiredfor the service type, pressures and temperatures of the application and perthe contractor’s Welding Procedure Specification (WPS).a. Install weld neck flanges at all valves, appurtenances, andequipment with flange type connections. Clean flange faces andinstall gaskets. Align flange surfaces parallel. Use suitablelubricants, such as Never Seize, on bolt threads. Tighten boltsgradually and uniformly with a torque wrench. Do not mate flatface flanges with raised face flanges.3. Flanged Joints: Align flange surfaces parallel. Assemble joints bysequencing bolt tightening to make initial contact of flanges and gaskets asflat and parallel as possible. Use suitable lubricants on bolt threads.Tighten bolts gradually and uniformly with a torque wrench.B. Nonferrous Pipe Joints:1. Brazed Joints: For copper tube and fitting joints, braze joints inaccordance with the AWS “Soldering Manual”, ASME Code for PressurePiping B31.1 Power Piping, ASME Code for Pressure Piping B31.9 –Building Services Piping, ANSI/ASHRAE Standard 152004 “SafetyStandard for Refrigeration Systems”, the Contractor’s tested BrazingProcedure Specification and the following:a. Fill and allow a trickle flow of an inert gas (ie., nitrogen) throughthe pipe and fittings during brazing to prevent formation of scale.Caution must be exercised not to allow the inert gas to deplete theoxygen, causing asphyxiation.b. Heat joints using oxyacetylene torch. Heat to proper and uniformbrazing temperature.BASIC PIPING MATERIALS AND METHODS150559