SECTION 23 22 13 STEAM AND CONDENSATE PIPING PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of Contract, including General and Supplementary Conditions and Division 1 Specification sections, apply to this section. B. The requirements of the following Division 23 Sections apply to this Section: 1. "Common Work Results for Mechanical" 2. "Hangers and Supports for HVAC Piping and Equipment" 1.2 SUMMARY A. This Section includes steam and condensate piping and specialties for building HVAC and domestic water heating systems. Materials and equipment in this Section include: 1. Pipes, fittings, and specialties 2. Special duty valves B. Related Sections: The following Sections contain requirements that relate to this Section: 1. Division 23 Section "Basic Mechanical Materials and Methods" for sealing pipe penetrations through basement walls and fire/smoke barriers. 2. Division 23 Section "Meters and Gauges" for thermometers, flow meters, and pressure and vacuum gauges. 3. Division 23 Section "Mechanical Identification" for labeling and identification of steam and condensate piping systems. 4. Division 23 Section "Vibration Control" for piping seismic support. 5. Division 23 Section "Mechanical Insulation" for pipe insulation. 1.3 DEFINITIONS A. Pipe sizes used in this Specification are Nominal Pipe Size (NPS). B. Low Pressure Steam Systems operate at 15 psig (100 kpa above atmospheric) and under. 1.4 SYSTEMS DESCRIPTION A. The steam and condensate piping systems for this project are two-pipe, mechanical flow systems. 1.5 SUBMITTALS A. Refer to Section "Basic Mechanical Requirements". 23 22 13-1
B. Product data, including rated capacities where applicable, furnished options and accessories, and installation instructions for: 1. Safety relief valves. 2. Pressure reducing valves. 3. Steam traps. 4. Air vents. 5. Strainers. 1.6 QUALITY ASSURANCE A. Regulatory Requirements: Comply with the provisions of the following: 1. ASME B 31.9 "Building Services Piping: For materials, products, and installation. Safety valves and pressure vessels shall bear the appropriate ASME label. 2. ASME "Boiler and Pressure Vessel Code", Section IX, "Welding and Brazing Qualification" for qualifications for welding processes and operators. PART 2 - PRODUCTS 2.1 MANUFACTURERS A. Manufacturers: Subject to compliance with requirements, provide steam and condensate piping system products from one of the following: 1. Safety Pressure Relief Valves: a. Armstrong Machine Works, A-Y Division b. Kunkle Valve Co., Inc. c. Lunkenheimer Co. d. Spirax Sarco. e. Watts Regulator Co. 2. Pressure Reducing Valves: a. Armstrong Machine Works, A-Y Division b. Fisher Controls International, Inc. c. Hoffman Specialty ITT; Fluid Handling Div. d. Leslie Co. e. Spirax Sarco. f. Spence Engineering Co., Inc. 3. Steam Traps: a. Armstrong Machine Works. b. ITT Hoffman c. Sarco 4. Air Vents: a. Armstrong Machine Works. 23 22 13-2
b. Eaton Corp.; Controls Div. c. Hoffman Specialty ITT; Fluid Handling Div. d. Spirax Sarco. 5. Strainers: a. Armstrong Machine Works. b. Hoffman Specialty ITT; Fluid Handling Div. c. Metraflex Co. d. Spirax Sarco. e. Victaulic Co. of America (low pressure applications only) f. Watts Regulator Co. 2.2 PIPE AND TUBE MATERIALS A. General: Refer to Part 3 below, Article "PIPE APPLICATION" for identification of systems where the below specified pipe and fitting materials are used. B. Steel Pipe: ASTM A 53, Schedule 40 and 80 for application as specified in Part 3 below, seamless, black steel pipe, with beveled ends. 2.3 FITTINGS A. Cast-Iron Threaded Fittings: ASME B16.4; Class 125 and Class 250 for piping 2 inches and smaller. B. Steel Fittings: ASTM A 234, seamless or welded, for welded joints. C. Cast-Iron Threaded Flanges: ANSI B16.1, Class 125; raised ground face, bolt holes spot faced. Threads shall conform to ANSI B1.20.1. D. Steel Flanges and Flanged Fittings: ANSI B16.5, including bolts, nuts, and gaskets of the following material group, end connection and facing: 1. Material Group: 1.1. 2. End Connections: Butt Welding. 3. Facings: Raised face. E. Unions: ANSI B16.39, malleable iron, Class 150 hexagonal stock, with ball-and-socket joints, metal-to-metal bronze seating surfaces; female threaded ends. Threads shall conform to ANSI B1.20.1. 2.4 JOINING MATERIALS A. Welding Materials: Comply, with Section II, Part C. ASME Boiler and Pressure Vessel Code for welding materials appropriate for the wall thickness and chemical analysis of the pipe being welded. B. Pipe Flange Gasket Material: ANSI B16.21 full-faced for cast iron and cast bronze flanges, and raised face for steel flanges. Thickness, material, and type suitable for design temperatures and pressures. 23 22 13-3
2.5 SAFETY VALVES A. General: Select steam safety valves for full relief of capacity of equipment served, in accordance with ASME Boiler and Pressure Vessel Code. Furnish complete with cast iron drip-pan elbow having threaded inlet and outlet with threads (FPT) conforming to ANSI B1.20.1; sized for full size of safety valve outlet connection. B. Bronze Safety Valves: Cast bronze body, Class 250, with threaded (MPT) inlet and threaded (FPT) outlet; forged copper alloy disc, fully enclosed cadmium plated steel spring having an adjustable pressure range and positive shut-off. Factory-set valves to relieve at 10 psi above operating pressure. C. Cast-Iron Safety Valves: Cast iron body and bronze seat, Class 250; forged copper alloy disc and nozzle; fully enclosed stainless steel spring having an adjustable pressure range and positive shut-off; threaded end connections for valves 2 inch and smaller, raised face flanged inlet and threaded outlet connections for valves 2-1/2 inch and larger. Factory-set valves to relieve at 10 psi above operating pressure. 2.6 PRESSURE REDUCING VALVES A. General: Select pressure reducing valves of size, capacity, and pressure rating as scheduled. Factory-set for inlet and outlet pressures as indicated. B. Valves Characteristics: Pilot-actuated, diaphragm type, with adjustable pressure range and positive shut-off; cast iron body with flanged end connections, hardened stainless steel trim, and replaceable valve head and seat. Provide main head stem guide fitted with flushing and pressure arresting device. Provide cover over pilot diaphragm for protection against dirt accumulation. 2.7 STEAM TRAPS A. Thermostatic Traps: Cast brass, angle pattern body, with integral union tailpiece and screw-in cap; maximum operating pressure of 25 psig; balanced pressure stainless steel or monel diaphragm or bellows element, with renewable hardened stainless steel valve head and seat. B. Float and Thermostatic Traps: ASTM A 278, Class 30 cast iron body and bolted cap; renewable, stainless steel float mechanism, with renewable, hardened stainless steel head and seat; balanced pressure thermostatic air vent made of stainless steel or monel bellows with stainless steel head and seat. 23 22 13-4
C. Thermodynamic Traps 1. Body: Stainless steel with screw-in cap. 2. End Connections: Threaded 3. Disc and Seat: Stainless steel. 4. Maximum Operating Pressure: 600 psig. 2.8 AIR VENTS A. Quick Vents: Cast iron or brass body, with balanced pressure stainless steel or monel thermostatic bellows, and stainless steel heads and seats. B. Float Vents: Cast iron or brass body; seamless brass float; balance pressure thermostatic bellows; replaceable stainless steel seat, float, and head. 2.9 STRAINERS A. Y-Pattern Strainers: Minimum 250 psig steam working pressure; cast iron body conforming to ASTM A 278, Class 30; threaded connections for 2 inch and smaller, flanged connections for 2-1/2 inch and larger; grade 18-8 stainless steel screen (20 mesh for 2 inch and smaller, and manufacturer recommended perforations for sizes 2-1/2 inch and larger); tapped blowoff plug. B. Basket Strainers: Minimum 250 psig steam working pressure; cast iron body conforming to ASTM A 278, Class 30; flanged connections; grade 18-8 stainless steel screen; bolted cover. PART 3 - EXECUTION 3.1 PIPE APPLICATIONS A. Install steel pipe with threaded joints and fittings for 2 inch and smaller, and with welded joints for 2-1/2 inch and larger. Steam supply pipe shall be schedule 40. Condensate return pipe shall be schedule 80. 3.2 PIPING INSTALLATIONS A. General Locations and Arrangements: Drawings, (plans, schematics, and diagrams) indicate the general location and arrangement of the piping systems. Location and arrangement of piping layout take into consideration pipe sizing and friction loss, expansion, pump sizing, and other design considerations. So far as practical, install piping as indicated. Refer to individual system specifications for requirements for coordination drawing submittals. B. Use fittings for all changes in direction and all branch connections. C. Conceal all pipe installations in walls, pipe chases, utility spaces, above ceilings, below grade or floors, unless indicated to be exposed to view. 23 22 13-5
D. Install exposed piping at right angles or parallel to building walls. Diagonal runs are not permitted, unless expressly indicated. E. Install piping free of sags or bends and with ample space between piping to permit proper insulation applications. F. Install piping tight to slabs, beams, joists, columns, walls, and other permanent elements of the building. Provide space to permit insulation applications, with 1 inch clearance outside the insulation. Allow sufficient space above removable ceiling panels to allow for panel removal. G. Locate groups of pipes parallel to each other, spaced to permit applying insulation and servicing of valves. H. Install drains at low points in mains, risers, and branch lines consisting of a tee fitting, 3/4 inch ball valve, and short 3/4 inch threaded nipple and cap. I. Fire Wall Penetrations: Where pipes pass through fire rated walls, partitions, ceilings, and floors, maintain the fire rated integrity. Refer to Division 7 for special sealers and materials. J. Install steam supply piping at a uniform grade of 1/4 inch in ten feet downward in the direction of flow. K. Install condensate return piping at a uniform grade of 1/2 inch in ten feet downward in the direction of flow. L. Install branch connections to supply mains using 45 degree fittings in main with take-off out the top of the main. Use of 90 degree "tee" fittings is permissible, where use of 45 degree fittings are not practical. Where the length of a branch takeoff is less than 10 feet, pitch branch line down toward mains, 1/2 inch per 10 feet. M. Make reductions in pipe sizes using eccentric reducer fitting installed with the level side down. N. Install unions in pipes 2 inch and smaller, adjacent to each valve, at final connections each piece of equipment, and elsewhere as indicated. Unions are not required on flanged devices. O. Install flanges on valves, apparatus, and equipment having 2-1/2 inch and larger connections. P. Install flexible connectors at inlet and discharge connections to pumps and other vibration producing equipment. 23 22 13-6
Q. Install strainers on the supply side of each control valve, pressure regulating valve, solenoid valve, traps, and elsewhere as indicated. Install 3/4 inch NPS nipple and ball valve in blow down connection of strainers 2 inch and larger. Use same size nipple and valve as blow-off connection of strainer. R. Anchor piping to ensure proper direction of expansion and contraction. Install expansion loops and joints as indicated on the Drawings and specified in Division 15 Section "Expansion Compensation". S. Install drip legs at low points and natural drainage points in the system, such as at the ends on mains, bottoms of risers, and ahead of pressure regulators, control valves, isolation valves, pipe bends, and expansion joints. 1. On straight runs with no natural drainage points, install drip legs at intervals not exceeding 200 feet where pipe is pitched down in the direction of the steam flow and a maximum of 150 feet where the pipe is pitched up so that condensate flow is opposite of steam flow. 2. Size drip legs at vertical risers full size and extend beyond the rise. Size drip legs at other locations same diameter as the main. Provide an 18 inch drip leg for steam mains smaller than 6 inch. In steam mains 6 inch and larger, provide drip legs sized 2 pipe sizes smaller than the main, but not less than 4 inch. 3. Drip legs, dirt pockets, and strainer blowdowns shall be equipped with gate valves to allow removal of dirt and scale. 4. Install steam traps close to drip legs. 3.3 HANGERS AND SUPPORTS A. General: Hanger, supports, and anchors devices are specified in Division 15 Section "Supports and Anchors". Conform to the table below for maximum spacing of supports: B. Install the following pipe attachments: 1. Adjustable steel clevis hangers for individual horizontal runs less than 20 feet in length. 2. Adjustable roller hangers and spring hangers for individual horizontal runs 20 feet or longer. 3. Pipe roller complete - MSS Type 44 for multiple horizontal runs, 20 feet or longer, supported on a trapeze. 4. Spring hangers to support vertical runs. 23 22 13-7
C. Install hangers with the following minimum rod sizes and maximum spacing: Nom. Pipe Size-Inch Max. Span-Ft. Min. Rod Size-Inch 1 7 3/8 1-1/2 9 3/8 2 10 3/8 3 12 1/2 3-1/2 13 1/2 4 14 5/8 5 16 5/8 6 17 3/4 8 19 7/8 10 22 7/8 12 23 7/8 D. Support vertical runs at each floor. 3.4 PIPE JOINT CONSTRUCTION A. Welded Joints: Comply with the requirements in ASME Code B31.9- "Building Services Piping." B. Threaded Joints: Conform to ANSI B1.20.1, tapered pipe threads for field cut threads. Join pipe, fittings, and valves as follows: 1. Note the internal length of threads in fittings or valve ends, and proximity of internal seat or wall, to determine how far pipe should be threaded into joint. 2. Align threads at point of assembly. 3. Apply appropriate tape or thread compound to the external pipe threads (except where dry seal threading is specified). 4. Assemble joint to appropriate thread depth. When using a wrench on valves place the wrench on the valve end into which the pipe is being threaded. 5. Damaged Threads: Do not use pipe with threads which are corroded or otherwise damaged. If a weld opens during cutting or threading operations, that portion of pipe shall not be used. C. Flanged Joints: Align flanges surfaces parallel. Assemble joints by sequencing bolt tightening to make initial contact of flanges and gaskets as flat and parallel as possible. Use suitable lubricants on bolt threads. Tighten bolts gradually and uniformly to appropriate torque specified by the bolt manufacturer. 23 22 13-8
3.5 STEAM TRAP INSTALLATIONS A. Install steam traps in accessible locations as close as possible to connected equipment. Maximum allowable distance from equipment is 4 feet. B. Unless otherwise indicated, install valve, strainer, and union upstream from the trap; install union, check valve, and valve downstream from trap. 3.6 VALVE APPLICATIONS A. General Duty Valve Applications: Where specific valve types are not indicated the following requirements apply: 1. Shut-off duty: Low pressure - Use gate and ball valves. Medium and high pressure - Use gate and ball valves. 2. Throttling duty: Use globe valves 3. Install shut-off duty valves at each branch connection to supply mains, and elsewhere as indicated. 4. Install throttling duty valves at supply connection to each piece of equipment, and elsewhere as indicated. B. Install drain valves at low points in mains, risers, branch lines, and elsewhere as required for system drainage. C. Install swing check valves as required to control flow direction, and to serve as "vacuum breakers." D. Install valves with unions or flanges at each piece of equipment arranged to allow service, maintenance, and equipment removal without system shutdown. 3.7 PRESSURE REDUCING VALVE INSTALLATIONS A. General: Install pressure reducing valves as required to regulate system pressure. Install in a location readily accessible for maintenance and inspection. B. Size reducing valves to supply the maximum steam requirements of the heating system or equipment indicated, at the indicated inlet and outlet pressures. C. Provide bypass around each reducing valve, with a globe valve equal in size to the area of the reducing valve seat ring. D. Install valves and unions around each reducing valve to facilitate removal and repair of reducing valves. Unions may be omitted for reducing valves with flanged connections. E. Install pressure gauges on the low pressure side of each reducing valve and ahead of the upstream shutoff valve. 23 22 13-9
1. On two-stage reducing stations, install a drip trap and pressure gauge upstream from the second stage reducing valve. F. Install strainers upstream for each reducing valve. 1. Install safety valves downstream from each reducing valve set a 5 psig higher that the reduced pressure when the reduced pressure is under 35 psig; and at 10 psig higher than the reduced pressure, if the reduced pressure is above 35 psig or the first-stage of twostage reducing. 3.8 SAFETY VALVE INSTALLATIONS A. Install relief valves in accordance with and where required by ASME B 31.1 - "Power Piping." Pipe discharge to atmosphere outside the building, without stop valves. Terminate vent pipe with screened vent cap. Install a drip pan elbow fitting adjacent to the safety valve. Pipe drip pan elbow drain connection to the nearest floor drain without valves. Comply with ASME Boiler and Pressure Vessel Code for installation requirements. 3.9 TERMINAL EQUIPMENT CONNECTIONS A. Piping size for supply and return shall be same size as the equipment connections. B. Install traps and control valves in accessible locations as close as possible to the equipment. C. Install vacuum breaker downstream from the control valve and bypass, and as close as possible to the coil inlet connection. D. Pipe outlet from coils to drip leg. From drip leg, install an appropriate trap, sized at 3 times the condensate load of the equipment, at 1/2 psig differential. 3.10 FIELD QUALITY CONTROL A. Preparation for testing: Prepare steam and condensate piping in accordance with ASME B 31.9 and as follows: 1. Leave joints including welds uninsulated and exposed for examination during the test. 2. Provide temporary restraints for expansion joints which cannot sustain the reactions due to test pressure. If temporary restraints are not practical, isolate expansion joints from testing. 3. Flush all new piping systems with clean water. Clean strainers. 4. Isolate equipment that is not to be subjected to the test pressure from the piping. If a valve is used to isolate the equipment, its closure shall be capable of sealing against the test pressure 23 22 13-10
without damage to the valve. Flanged joints at which blinds are inserted to isolate equipment need not be tested. 5. Install relief valve set at a pressure no more than 1/3 higher than the test pressure, to protect against damage by expansion of liquid or other source of overpressure during the test. B. Testing: Test steam and condensate piping as follows: 1. Use ambient temperature water as the testing medium, except where there is a risk of damage due to freezing. Another liquid may be used if it is safe for workmen and compatible with the piping system components. 2. Use traps installed at high points in the system to release trapped air while filling the system. Use drip legs installed at low points for complete removal of the liquid. 3. Examine system to see that equipment and parts that cannot withstand test pressures are properly isolated. Examine test equipment to ensure that it is tight and that low pressure filling lines are disconnected. 4. Subject piping system to a hydrostatic test pressure which at every point in the system is not less than 1.5 times the design pressure. The test pressure shall not exceed the maximum pressure for any vessel, pump, valve, or other component in the system under test. Make a check to verify that the stress due to pressure at the bottom of vertical runs does not exceed either 90 percent of specified minimum yield strength, or 1.7 times the "SE" value in Appendix A of ASME B31.9. 5. After the hydrostatic test pressure has been applied for at least 10 minutes, examine the system for leakage. Eliminate leaks by tightening, repairing, or replacing components as appropriate, and repeat hydrostatic test until there are no leaks. 3.11 CLEANING A. Flush the system with clean water. Remove, clean, and replace strainer screens. - - - END - - - 23 22 13-11