Section 15182 - steam and condensate piping

03/07/08
SECTION 232213 – STEAM AND CONDENSATE PIPING 03/07/08
SECTION 232213 - STEAM AND CONDENSATE PIPING Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 1 Specification Sections, apply to this Section. This Section includes steam and condensate piping and specialties for systems up to 125 psig, inside the building. HP Systems: High-pressure systems operating at more than 30 psig. LP Systems: Low-pressure systems operating at 30 psig or less. Product Data: For each type of special-duty valve and steam trap indicated, including rated capacities and accessories. Shop Drawings: Detail flash tank assemblies and fabrication of pipe anchors, hangers, special pipe support assemblies, alignment guides, and expansion joints and loops and their attachment to the building structure. Include dimensions, weights, loadings, required clearances, method of field assembly, components, and location and size of each field connection. Welding Certificates: Copies of certificates for welding procedures and personnel. Field Test Reports: Written reports of tests specified in Part 3 of this Section. Include the following: Test results that comply with requirements. Failed test results and corrective action taken to achieve requirements. Maintenance Data: For steam traps, vacuum breakers, and meters to include in maintenance manuals specified in Division 1. Welding Procedure Specification, WPS. It must have a specific procedure number, date written and identification of the person who wrote it. Procedure Qualification Record, PQR. This is the record that indicates the procedure to be followed is a valid procedure. 03/07/08
Welding Operator Qualifications test, WPQ. This is a record, including bend test results or radiographic test results, for each welder. The WPQ is based on that company's procedure. It shall be certified and dated by the test agency within 12 months of the start of the work for the welder. Welding and brazing procedure qualifications: 1. Contractor shall submit for review the Contractor’s standard welding and brazing procedures (forms WPS or BPS). Procedure shall be submitted on PQR form as described in the ASME Boiler and Pressure Vessel Code. The PQR shall be supported by the appropriate WPS and BPS. All welders shall be certified to the WPS and BPS as listed on the Contractor’s PQR. Certifications are to be performed by an independent testing laboratory within twelve months prior to the commencement of work. 1. Each welder is to stamp the pipe adjacent to each weld performed by him/her. The Contractor is required to, via the submittal process, provide a list of each welder’s name and the mark used by each welder. Tack welding may be performed by non-certified welders. All tack welds, whether performed by certified or non-certified welders, must be ground out and removed. Contractor option: In lieu of submitting the contractor’s welding procedures, the contractor may adopt Dartmouth College’s procedure #1.1.1.2 Rev. 0 and ASME/ANSI B3 1.1, latest edition. The welding procedure is available from DC Facilities Operation and Management. No welding may take place until a satisfactory reviewed submittal is complete. It is the contractor’s responsibility to provide a submittal in a timely fashion so as not to delay the project. Soldering and brazing procedures for refrigeration piping shall conform to ANSI B9. 1 “Standard Safety Code for Mechanical Refrigeration.” ASME Compliance: Comply with ASME B31.9, "Building Services Piping," for materials, products, and installation. Safety valves and pressure vessels shall bear the appropriate ASME label. Fabricate and stamp flash tanks to comply with the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. Coordinate layout and installation of steam and condensate piping and suspension system components with other construction, including light fixtures, hydronic piping, fire-suppression-system components, and partition assemblies. Coordinate pipe sleeve installation for foundation wall penetrations. Coordinate piping installation with roof curbs, equipment supports, and roof penetrations. Roof specialties are specified in Division 7 Sections. Coordinate pipe fitting pressure classes with products specified in related Sections. 03/07/08
Coordinate size and location of concrete bases. Cast anchor-bolt inserts into bases. Concrete, reinforcement, and formwork requirements are specified in Division 3 Sections. Coordinate installation of pipe sleeves for penetrations through exterior walls and floor assemblies. Coordinate with requirements for firestopping specified in Division 7 Section "Through-Penetration Firestop Systems" for fire and smoke wall and floor assemblies. All pipe and fittings shall be fabricated in the USA or Canada. Elbows for all pipe sizes over 2" diameter shall be long radius type (1.5 pipe diameter to centerline of pipe). Use reducers, increasers, or reducing tees for change of pipe size. Bushings are not allowed. Forged steel (3,000#) branch connectors (ie “Weld-O-Lets”, “Thread-O-Lets”), per the limits set forth in Part 3 of this section, may be used to create branch connections in steel piping systems. All branch connectors shall be 3,000# fittings. General: Refer to Part 3 piping application articles for applications of pipe and fitting materials. Steam Supply Pipe: Threaded and welded ends. ITEM
SIZE
ASTM SPEC NO.
MATERIAL WEIGHT & TYPE
03/07/08
Gravity & Pumped Condensate: Threaded and welded ends. ITEM
SIZE
ASTM SPEC NO.
MATERIAL WEIGHT & TYPE
Class 300, RF, weld neck or slip on, ANSI Hex head (ANSI B 18.2.1), B1.1, class 2A Unions: ANSI B16.39, malleable-iron, class 300 for schedule 80 piping system, hexagonal stock, with ball and socket joints, metal to metal bronze seating surfaces; female threaded ends. Threads shall conform to ANSI B1.20.1. Flexible Connectors: Stainless steel bellows with woven, flexible, bronze, wire-reinforcing protective jacket; 150-psig minimum working pressure and 250 deg F maximum operating temperature. Connectors shall have flanged or threaded-end connections to match equipment connected and shall be capable of 3/4-inch misalignment. Manufacturers: Keflex, Mason, Metraflex. Welding Materials: Comply with Section II, Part C, of the ASME Boiler and Pressure Vessel Code for welding materials appropriate for wall thickness and for chemical analysis of pipe being welded. Globe, check, ball, and butterfly valves are specified in Division 15 Section "Valves." Refer to Part 3 "Valve Applications" Article for applications of each valve. Steam mains shall have isolation valves space no further than 200’ apart. Steam isolation valves larger than 6” shall be equipped with 2” ball warm-up valves. 03/07/08
Size and Capacity: As required for equipment according to the ASME Boiler and Pressure Vessel Code. 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" and smaller, raised face flanged inlet and threaded outlet connections for valves 2–1/2" and larger. Factory set valves to relieve at 10 psi above operating pressure. Manufacturer
Bronze
Cast Iron
Drip Pan Elbow
Stop-Check Valves: Class 250, malleable-iron body and bonnet, cylindrical disc, removable liner and machined seat, brass-alloy stem, outside screw and yoke, polytetrafluoroethylene-impregnated packing with 2-piece packing gland assembly, flanged end connections, and cast-iron handwheel. Balanced Pressure 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. 1. 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. 1. Spirax/Sarco FT-30, FTI-30 (no substitutions). Inverted Bucket Traps: ASTM A 278, Class 30 cast iron body and cap, pressure rated for 250 psi; stainless steel head and seat; stainless steel valve retainer, lever, guide pin assembly, brass or stainless steel bucket. 1. 03/07/08
Cast iron or brass body, with balanced pressure stainless steel or monel thermostatic bellows, and stainless steel heads and seats., 1. Stainless steel or brass construction, factory set to open at 2" H2O of vacuum, and shall be of a hardened ball check valve or spring restrained style. All spring style components shall be encapsulated with a protective cover. 1. Spirax/Sarco Y-Pattern Strainers: 250-psig working steam pressure; ASTM A 126, Class B cast-steel body; stainless-steel screen, No. 20 mesh for NPS 2 and smaller and manufacturer's recommended perforations for NPS 2-1/2 and larger; tapped blowoff plug. Threaded connections for strainers NPS 2 and smaller and flanged connections for strainers NPS 2-1/2 and larger. Condensate systems and strainers prior to steam traps shall be cast-iron. Basket Strainers: 250-psig working steam pressure; ASTM A 126, Class B cast-iron body; stainless-steel screen; bolted cover; threaded connections for strainers NPS 2 and smaller and flanged connections for strainers NPS 2-1/2 and larger. Shop or factory fabricated of welded steel according to the ASME Boiler and Pressure Vessel Code, for 150-psig rating; and bearing ASME label. Fabricate with tappings for vents, low-pressure steam and condensate outlets, high-pressure condensate inlet, air vent, safety valve, and legs. Size, Capacity, and Pressure Rating: Factory set for inlet and outlet pressures indicated.
Valve Characteristics: Pilot-actuated, diaphragm type, with adjustable pressure range
and positive shutoff. Valves shall have cast-iron body with threaded connections for
valves NPS 2 and smaller and flanged connections for valves NPS 2-1/2 and larger; and
hardened stainless-steel trim, replaceable head and seat, main head stem guide fitted with
flushing and pressure-arresting device, cover over pilot diaphragm, and non-asbestos
gaskets. Provide removable insulating jacket.
Pilot actuated, diaphragm type, Class 250, with adjustable pressure range and positive shut off; cast iron body with flanged or threaded end connections, hardened stainless steel trim, and replaceable valve head and seat. Provide main head stem guide fitted with flushing and 03/07/08
pressure arresting device. Provide cover over pilot diaphragm for protection against dirt accumulation. 1. Spirax/Sarco 2. NPS 2 and Smaller: Schedule 40 steel pipe, with threaded joints using Class 125 NPS 2-1/2 through NPS 12: Schedule 40 steel pipe, with welded joints using Schedule 40 wrought-steel welding fittings and Class 150 wrought-steel flanges. NPS 2 and Smaller: Schedule 80 steel pipe, with threaded joints using extra NPS 2-1/2 through NPS 12: Schedule 80 steel pipe, with welded joints using Schedule 80 wrought-steel welding fittings and Class 300 wrought-steel flanges. HP STEAM PIPING APPLICATIONS
Steam Piping, NPS 2 and Smaller: Schedule 40 steel pipe, with threaded joints using
Class 300 malleable-iron fittings.
Steam Piping, NPS 2-1/2 through NPS 12: Schedule 40 steel pipe, with welded joints using
Schedule 40 wrought-steel welding fittings and Class 150 wrought-steel flanges.
Steam Piping, NPS 14 through NPS 18: Schedule 30 steel pipe, with welded joints using
Schedule 30 wrought-steel welding fittings and Class 150 wrought-steel flanges.
Steam Piping NPS 20: Schedule 20 steel pipe, with welded joints using Schedule 20
wrought-steel welding fittings and Class 150 wrought-steel flanges.
Condensate Piping, NPS 2 and Smaller: Schedule 80 steel pipe, with threaded joints using
Class 300 malleable-iron fittings.
Condensate Piping, NPS 2-1/2 through NPS 12: Schedule 80 steel pipe, with welded joints
using Schedule 80 wrought-steel welding fittings and Class 150 wrought-steel flanges.
General-Duty Valve Applications: Unless otherwise indicated, use the following valve types: Shutoff Duty: Ball and high-performance butterfly valves. 03/07/08
Install shutoff-duty valves at each branch connection to supply mains, at inlet connection to each steam trap, and elsewhere as indicated. Thermostatic Traps: Convectors and finned-tube radiation. Float and Thermostatic Traps: Steam main and riser drip legs, laundry equipment, kitchen equipment, heat exchangers, and heating coils. STEAM-TRAP
APPLICATIONS
Thermostatic Traps: Convectors and finned-tube radiation.
Inverted Bucket Traps: Steam main and riser drip legs, and laundry equipment.
Float and Thermostatic Traps: Lab equipment, heat exchangers, and heating coils.
Thermodynamic Traps: Steam main and riser drip legs, and heat tracer lines.
Refer to Division 15 Section "Basic Mechanical Materials and Methods" for basic piping installation requirements. Install groups of pipes parallel to each other, spaced to permit applying insulation and servicing of valves. Install drains, consisting of a tee fitting, NPS 3/4 ball valve, and short NPS 3/4 threaded nipple with cap, at low points in piping system mains and elsewhere as required for system drainage. Install steam supply piping at a uniform grade of 0.2 percent downward in direction of steam flow. Install condensate return piping at a uniform grade of 1 percent downward in direction of condensate flow. Reduce pipe sizes using eccentric reducer fitting installed with level side down. Unless otherwise indicated, install branch connections to steam mains using 45-degree fittings in main pipe, with the takeoff coming out the top of the main pipe. Use of 90-degree tee fittings is permissible if 45-degree fittings are impractical. If length of branch takeoff is less than 10 feet, pitch branch line down toward mains at a 0.4 percent grade. Install unions in piping NPS 2 and smaller adjacent to each valve, at final connections of each piece of equipment, and elsewhere as indicated. Install flanges in piping NPS 2-1/2 and larger at final connections of each piece of equipment and elsewhere as indicated. 03/07/08
Install strainers on supply side of each control valve, pressure-reducing valve, solenoid valve, traps, and elsewhere as indicated. Install NPS 3/4 nipple and ball valve in blowdown connection of strainers NPS 2 and larger. Match size of strainer blowoff connection for strainers smaller than NPS 2. Anchor piping for proper direction of expansion and contraction. 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, expansion joints, at intervals not exceeding 150' where pipe is pitched down in the direction of the steam flow, a maximum of 100' where the pipe is pitched up in the direction of steam flow. 1. Drip legs, dirt pockets, and strainer blowdowns shall be equipped with drain valves (& caps) to allow removal of dirt and scale. Install steam traps close (<3') to drip legs and at least 8" below the header. Drain valves serving drip legs shall be lower than the trap connection and never attached to the trap connection. Drip legs shall be sized per the following schedule: Header Size
Drip Leg Size
Pitch condensate piping down toward flash tank. If more than one condensate pipe discharges into flash tank, install a swing check valve in each line. Install thermostatic air vent at top of tank. Install inverted bucket or float and thermostatic trap at low-pressure condensate outlet, sized for three times the condensate load. Install safety valve at tank top. Install pressure gage, gate valve, and swing check valve on low-pressure (flash) steam outlet. Install steam traps in accessible locations as close as possible to connected equipment, but not more than 48 inches from connected equipment. Unless otherwise indicated, install isolation valve, strainer (leg vertical), and union upstream from the trap; install union, test tee with test valve, check valve, and isolation valve downstream from trap. Install safety valves according to ASME B31.1. Pipe safety valve discharge without valves to atmosphere outside building. Install drip-pan elbow fitting adjacent to safety valve and pipe drain connection to nearest floor drain. 03/07/08
Install steam traps in accessible locations as close as possible to connected equipment. Install isolation valve, strainer (leg vertical), and union upstream from the trap; install union, test tee with test valve, check valve, and isolation valve downstream from trap. PRESSURE-REDUCING VALVE INSTALLATION
Consult manufacturers for proper installation of piping to and from pressure-reducing
valves.
Install pressure-reducing valves in readily accessible location for maintenance and
inspection.
Install bypass piping around each pressure-reducing valve, with globe valve equal in size
to area of pressure-reducing valve seat ring, unless otherwise indicated.
Install gate valves around each pressure-reducing valve.
Install unions around each pressure-reducing valve having threaded-end connections.
Install pressure gages on low-pressure side of each pressure-reducing valve and ahead of
shutoff valve. Install pressure gages downstream from globe valve on pressure-reducing
valve bypass.
On two-stage pressure-reducing stations, install drip trap and pressure gage upstream
from second stage pressure-reducing valve.
Install strainers upstream for each pressure-reducing valve.
Install safety valves downstream from each pressure-reducing valve station.
Install removable insulating jacket.
Hanger, support, and anchor devices are specified in Division 15 Section "Hangers and Supports." Adjustable steel clevis hangers for individual horizontal piping less than 20 feet long. Adjustable roller hangers and spring hangers for individual horizontal piping 20 feet or longer. Pipe Roller: MSS SP-58, Type 44 for multiple horizontal piping 20 feet or longer, supported on a trapeze. Spring hangers to support vertical runs. Install hangers with the following maximum spacing and minimum rod sizes: 03/07/08
NPS 3/4: Maximum span, 9 feet; minimum rod size, 1/4 inch. NPS 1: Maximum span, 9 feet; minimum rod size, 1/4 inch. NPS 1-1/2: Maximum span, 12 feet; minimum rod size, 3/8 inch. NPS 2: Maximum span, 13 feet; minimum rod size, 3/8 inch. NPS 2-1/2: Maximum span, 14 feet; minimum rod size, 3/8 inch. NPS 3: Maximum span, 15 feet; minimum rod size, 3/8 inch. NPS 4: Maximum span, 17 feet; minimum rod size, 1/2 inch. NPS 6: Maximum span, 21 feet; minimum rod size, 1/2 inch. NPS 8: Maximum span, 24 feet; minimum rod size, 5/8 inch. NPS 10: Maximum span, 26 feet; minimum rod size, 3/4 inch. NPS 12: Maximum span, 30 feet; minimum rod size, 7/8 inch. NPS 14: Maximum span, 32 feet; minimum rod size, 1 inch NPS 16: Maximum span, 35 feet; minimum rod size, 1 inch. NPS 18: Maximum span, 37 feet; minimum rod size, 1-1/4 inches. NPS 20: Maximum span, 39 feet; minimum rod size, 1-1/4 inches. Support vertical runs at roof, at each floor, and at 10-foot intervals between floors. Refer to Division 15 Section "Basic Mechanical Materials and Methods" for joint construction requirements for threaded, welded, and flanged joints. Size for supply and return piping connections shall be same as for equipment connections. Install traps and control valves in accessible locations close to connected equipment. Install bypass piping with globe valve around control valve. If multiple, parallel control valves are installed, only one bypass is required. Install vacuum breaker downstream from control valve and bypass and close to coil inlet connection. Install ports for pressure and temperature gages at coil inlet connections. Prepare steam and condensate piping according to ASME B31.9 and as follows: Leave joints, including welds, uninsulated and exposed for examination during test. Flush system with clean water. Clean strainers. Isolate equipment from piping. If a valve is used to isolate equipment, its closure shall be capable of sealing against test pressure without damage to valve. Install blinds in flanged joints to isolate equipment. Install safety valve, set at a pressure no more than one-third higher than test pressure, to protect against damage by expanding liquid or other source of overpressure during test. 03/07/08
Perform the following tests on steam and condensate piping: Use ambient temperature water as a testing medium unless there is risk of damage due to freezing. Another liquid that is safe for workers and compatible with piping may be used. While filling system, use vents installed at high points of system to release trapped air. Use drip legs installed at low points for complete draining of liquid. Subject piping system to hydrostatic test pressure that is not less than 1.5 times the design pressure. Test pressure shall not exceed maximum pressure for any vessel, pump, valve, or other component in system under test. Verify that stress due to pressure at bottom of vertical runs does not exceed either 90 percent of specified minimum yield strength or 1.7 times "SE" value in Appendix A of ASME B31.9, "Building Services Piping." After hydrostatic test pressure has been applied for at least 10 minutes, examine piping, joints, and connections for leakage. Eliminate leaks by tightening, repairing, or replacing components, and repeat hydrostatic test until there are no leaks. Mark calibrated nameplates of pump discharge valves after steam and condensate system balancing has been completed, to permanently indicate final balanced position. Perform these adjustments before operating the system: Open valves to fully open position. Close coil bypass valves. Set temperature controls so all coils are calling for full flow. Check operation of automatic bypass valves. Flush steam and condensate piping with clean water. Remove and clean or replace strainer screens. Provide cleaning of steam and condensate piping systems as follows: Disconnect steam traps, and bypass steam through condensate piping. Flush piping system, under full steam pressure, wasting condensate until dirt, grease and oil are removed. Flushing period shall be minimum two days. Take samples (approximately one pint, each) twice each day and allow samples to cool to room temperature in clean, covered glass containers for Architect's inspection. Reinstall traps and operate system at normal pressure for period of five days. Waste condensate to drain during this period. Clean strainers as often as necessary to ensure clean systems. Upon completion, clean traps, valves, strainers, dirt pockets and other apparatus where dirt may accumulate.

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