SECTION STEAM AND STEAM CONDENSATE SPECIALTIES

Transcription

1 SECTION STEAM AND STEAM CONDENSATE SPECIALTIES PART 1 - GENERAL 1.1 DESCRIPTION OF WORK A. Steam traps. B. Steam air vents. C. Vacuum breakers. D. Drip pan elbows. E. Overflow drainer. 1.2 REFERENCES A. ANSI/ASTM - Boiler and Pressure Vessel Code. B. ASTM A105 - Forgings, Carbon Steel, for Piping Components. C. ASTM A126 - Gray Iron Castings for Valves, Flanges, and Pipe Fittings. D. ASTM A216 - Steel Casings, Carbon, Suitable for Fusion Welding, for High Temperature Service. E. ASME B Building Services Piping. 1.3 REGULATORY REQUIREMENTS A. Conform to ASME B Building Services Piping. 1.4 QUALITY ASSURANCE A. Manufacturer: For each product specified, provide components by same manufacturer throughout. 1.5 SUBMITTALS A. Submit shop drawings and product data for manufactured products and assemblies required for this project. B. Include product description, model, dimensions, component sizes, rough-in requirements, service sizes, and finishes. C. Submit schedule indicating manufacturer, model number, size, location, rated capacity, and features for each specialty with cross reference to supporting product data. GMP-R1 Addendum # Randall Stout Architects, Inc.

2 1.6 EXTRA STOCK A. Provide two service kits for each size and type of steam trap. PART 2 - PRODUCTS 2.1 FLOAT AND THERMOSTATIC TRAPS A. ASTM A126, cast iron or semi-steel body and bolted cover rated for maximum system pressure or 125 psig, whichever is greater; provide access to internal parts without disturbing piping; with bottom drain plug, stainless steel balanced pressure type air vent rated for 45 F of superheat, stainless steel float, stainless steel lever and valve assembly. B. Manufacturer 2. Armstrong. 2.2 STEAM AIR VENTS A. Balanced pressure type with ASTM A126 cast iron body and cover for maximum system pressure or 125 psig WSP whichever is greater; provide access to internal parts without disturbing piping; stainless steel bellows, stainless steel valve and seat. B. Manufacturer 2. Armstrong. 2.3 VACUUM BREAKERS A. Vacuum breakers shall be used on all modulating or on/off exchangers and coils. They shall be installed in the supply side between the control valve and equipment and be of hardened ball check valve design with all working parts manufactured from stainless steel. Bodies shall be made from stainless steel and shall be suitable for operating conditions of 304 psig saturated steam. 1. Body: Cast iron, bronze, or stainless steel. 2. End Connections: Threaded. 3. Sealing Ball, Retainer, Spring, and Screen: Stainless steel. 4. O-ring Seal: EPR. B. Vacuum Breakers shall require a vacuum of no greater than 2 inches of H2O to open. GMP-R1 Addendum # Randall Stout Architects, Inc.

3 C. Manufacturers 2. Armstrong. 2.4 DRIP PAN ELBOWS A. Drip pan elbows for use with safety valves shall be cast iron rated in accordance with ASTM A126 Class B, and be of the same size as the safety relief outlet or larger. B. All risers shall have drip pan elbows and the riser pipe after the drip pan elbow shall be unrestricted and larger than the drip pan inlet size. C. Manufacturers 2. Armstrong. 2.5 STEAM SAFETY VALVES A. Size and Capacity: As required for equipment according to ASME Boiler and Pressure Vessel Code. Furnish complete with cast-iron drip pan elbow having threaded or flanged inlet, and threaded drain connection. B. Bronze Safety Valves 1. Disc Material: Forged copper alloy. 2. End Connections: Threaded inlet and outlet. 3. Spring: Fully enclosed steel spring with adjustable pressure range and positive shutoff, factory set and sealed. 4. Pressure Class: Drip-Pan Elbow: Cast iron and having threaded inlet and outlet with threads complying with ASME B Size and Capacity: As required for equipment according to ASME Boiler and Pressure Vessel Code. C. Cast Iron Safety Valves 1. Disc Material: Forged copper alloy with bronze nozzle. 2. End Connections: Raised-face flanged inlet and threaded or flanged outlet connections. 3. Spring: Fully enclosed cadmium-plated steel spring with adjustable pressure range and positive shutoff, factory set and sealed. GMP-R1 Addendum # Randall Stout Architects, Inc.

4 4. Pressure Class: Drip-Pan Elbow: Cast iron and having threaded inlet, outlet, and drain, with threads complying with ASME B Exhaust Head: Cast iron and having threaded inlet and drain, with threads complying with ASME B Size and Capacity: As required for equipment according to ASME Boiler and Pressure Vessel Code. D. Manufacturer 2. Fisher. 2.6 AUTOMATIC STEAM CONTROL VALVES A. Furnish and install as specified on plans for the control of steam entering heating hot water heat exchanger. B. Valves shall be two-port single seated ductile iron globe type conforming to ANSI/ASME standards. Valve shall provide characterized modulating flow control. Valve plug, stem, and seat shall be of stainless steel. Shut-off tightness shall be ANSI class IV or better. Valve rangeability shall be 50:1 or better. Stem seal shall be PTFE chevron type. C. Actuators shall be electric, reversible, and have linear output. Supply voltage to be 110 VAC. Shall be supplied with a positioner card capable of accepting both a 4-20mA and 2-10VDC control signal. D. Control signal shall come from BAS or single loop electronic controller, as specified on plans. Single loop controller shall be powered from a 110 VAC source. Accuracy to be ±0.25% of span, and output signal to be 4-20mA. Controller to incorporate autotune and fuzzy logic features. Pt100 temperature sensors/transmitters shall be used for temperature control. E. Manufacturer 2. Fisher. 1.6 FLASH TANKS A. Shop or factory fabricated of welded steel according to ASME Boiler and Pressure Vessel Code, for 150-psig rating; and bearing ASME label. Fabricate with tappings for low-pressure steam and condensate outlets, high-pressure condensate inlet, air vent, safety valve, and legs. 1.7 PRESSURE-REDUCING VALVES A. Manufacturers GMP-R1 Addendum # Randall Stout Architects, Inc.

5 1. Armstrong International, Inc. 2. Hoffman Specialty; Division of ITT Industries. 3. Leslie Controls, Inc. 4. Spence Engineering Company, Inc. 5. Spirax Sarco, Inc. B. Size, Capacity, and Pressure Rating: Factory set for inlet and outlet pressures indicated. C. Description: Pilot-actuated, diaphragm type, with adjustable pressure range and positive shutoff. D. Select pressure-reducing valves to develop no more than 85 dba at an elevation of 3 feet above adjacent floor and at 3 feet in any direction. E. Body: Cast iron. F. End Connections: Threaded connections for valves NPS 2 (DN 50) and smaller and flanged connections for valves NPS 2-1/2 (DN 65) and larger. G. Trim: Hardened stainless steel. H. Head and Seat: Replaceable, main head stem guide fitted with flushing and pressure-arresting device cover over pilot diaphragm. I. Gaskets: Non-asbestos materials. 1.8 STEAM METERS A. Manufacturers 1. EMCO Flow Systems; Division of Advanced Energy Company. 2. ISTEC Corp. 3. Preso Meters; a division of Racine Federated Inc. 4. Spirax Sarco, Inc. B. Meters shall have a microprocessor to display totalizer flow, flow rate, temperature, pressure, time, and date; alarms for high and low flow rate and temperature. 1. Computer shall have 4 to 20-mA or 2 to 10 volt output for temperature, pressure, and contact closure for flow increments. 2. Independent timers to store four peak flow rates and total flow. 3. Interface compatible with central workstation described in Division 15 Section "HVAC Instrumentation and Controls." 4. Microprocessor Enclosure: NEMA 250, Type 4. GMP-R1 Addendum # Randall Stout Architects, Inc.

6 C. Sensor: Vortex type with stainless-steel wetted parts and flange connections; and with a piezoelectric sensor removable and serviceable without shutting down the process. At least 10:1 turndown with plus or minus 1 percent accuracy over full-flow range. 1.9 OVERFLOW DRAINER A. Furnish and install an overflow drainer for the deaerator and humidifier condensate drain lines. Unit shall be cast iron with 150 lb. flanged connections. B. Manufacturer: Warren. PART 2 - EXECUTION 2.1 INSTALLATION AND APPLICATION A. Install drip legs at low points and natural drainage points such as ends of mains, bottoms of risers, and ahead of pressure regulators, and control valves. 1. On straight runs with no natural drainage points, install drip legs at intervals not exceeding 300 feet. 2. Size drip legs same size as main. In steam mains NPS 6 and larger, drip leg size can be reduced, but to no less than NPS 4. B. Install specialties in accordance with manufacturer's instructions. C. Install float and thermostatic traps to drain condensate where shown. D. Size steam traps to handle minimum of two times maximum condensate load of apparatus served. E. Traps used on steam mains and branches shall be minimum 3/4 inch size. F. Install steam traps with union or flanged connections at both ends. G. Provide globe valve and strainer at inlet, and globe valve and check valve at discharge of steam traps. H. Provide minimum 10 inch long dirt pocket of same pipe sizes as apparatus return connection between apparatus and steam trap. I. Remove thermostatic elements from steam traps during temporary and trial usage, and until system has been operated and dirt pockets cleaned of sediment and scale. J. Terminate equipment relief valves to roofs. Provide drip pan elbow with drain connection to nearest floor drain. K. Each relief valve vent shall run to the roof separately except where otherwise noted on the drawings. L. Flash Tank 1. Pitch condensate piping down toward flash tank. GMP-R1 Addendum # Randall Stout Architects, Inc.

7 2. If more than one condensate pipe discharges into flash tank, install a check valve in each line. 3. Install thermostatic air vent at tank top. 4. Install safety valve at tank top. 5. Install full-port ball valve, and swing check valve on condensate outlet. 6. Install inverted bucket or float and thermostatic trap at low-pressure condensate outlet, sized for three times the calculated heat load. M. Air vent discharge piping shall run to a floor sink or otherwise safe location so as not to endanger personnel or equipment. 2.2 PRESSURE-REDUCING VALVE INSTALLATION A. Install pressure-reducing valves in accessible location for maintenance and inspection. B. Install bypass piping around pressure-reducing valves, with globe valve equal in size to area of pressure-reducing valve seat ring, unless otherwise indicated. C. Install gate valves on both sides of pressure-reducing valves. D. Install unions or flanges on both sides of pressure-reducing valves having threaded- or flangedend connections respectively. E. Install pressure gages on low-pressure side of pressure-reducing valves after the bypass connection according to Division 15 Section "Meters and Gages." F. Install strainers upstream for pressure-reducing valve. G. Install safety valve downstream from pressure-reducing valve station. 2.3 STEAM OR CONDENSATE METER INSTALLATION A. Install meters with lengths of straight pipe upstream and downstream according to steam meter manufacturer's instructions. B. Provide data acquisition wiring. Refer to Division 15 Section "HVAC Instrumentation and Controls." 2.4 SAFETY VALVE INSTALLATION A. Install safety valves according to ASME B31.1, "Power Piping" and ASME B31.9, "Building Services Piping." B. Pipe safety-valve discharge without valves to atmosphere outside the building. C. Install drip-pan elbow fitting adjacent to safety valve and pipe drain connection to nearest floor drain. GMP-R1 Addendum # Randall Stout Architects, Inc.

8 D. Install exhaust head with drain to waste, on vents equal to or larger than NPS 2-1/2. END OF SECTION GMP-R1 Addendum # Randall Stout Architects, Inc.