SECTION STEAM AND STEAM CONDENSATE SPECIALTIES

Transcription

1 SECTION STEAM AND STEAM CONDENSATE SPECIALTIES PART 1 - GENERAL 1.1 SECTION INCLUDES A. Steam Traps. B. Flash Tanks. C. Condensate Return Units. D. Pressure Reducing Valves. E. Safety Valves. F. Electric Steam Humidifier. G. Vacuum Breakers. 1.2 REFERENCES A. ANSI/ASTM - Boilers and Pressure Vessels Code. B. ANSI/NFPA 70 - National Electrical Code. C. ARI Standard for Commercial and Industrial Humidifiers. D. ASTM A105 - Forgings, Carbon Steel, for Piping Components. E. ASTM A126 - Gray Iron Castings for Valves, Flanges, and Pipe Fittings. 1.3 QUALITY ASSURANCE A. Manufacturer: For each product specified, provide components by same manufacturer throughout. B. Traps: Remanufactured traps are not acceptable. 1.4 SUBMITTALS A. Submit product data under provisions of Section Include product description, model, dimensions, component sizes, rough-in requirements, service sizes, and finishes. B. Submit schedule indicating manufacturer, model number, size, location, rated capacity, and features for each specialty. C. Submit manufacturer's installation instructions. D. Submit operation and maintenance data. E. Submit certification that all steam and steam condensate specialties, accessories, and components will withstand seismic forces defined in Specification Section Include the following: 1. Basis for Certification: Indicate whether certification is based on actual test of assembled components or on calculation. a. The term "withstand" means "the unit will remain in place without separation of any parts from the device when subjected to the seismic KJWW #

2 forces specified and the unit will be fully operational after the seismic event." 2. Dimensioned Outline Drawings of Equipment Unit: Identify center of gravity and locate and describe mounting and anchorage provisions. 3. Detailed description of equipment anchorage devices on which the certification is based and their installation requirements. PART 2 - PRODUCTS 2.1 STEAM TRAPS A. Furnish traps as scheduled on the drawings. B. Type T-1: Inverted bucket type with thermic vent, 250 psig rated, cast iron body, side inlet and outlet, and all internal components constructed of stainless steel and renewable inline. Acceptable Products (0-250 psig): Armstrong Machine Works Series 800T Spirax/Sarco Co., Inc. Type B Hoffman Industrial Specialties Co. Series 600 T Clark-Reliance Series 120 C. Type T-2: Thermostatic type with body and cap of cast brass, bronze bellows, stainless steel valve head and seat. Acceptable Products (0-25 psig): Spirax/Sarco Co. Inc. Hoffman Industrial Specialties Co. Clark-Reliance Type TD Type C Series T D. Type T-3: Float and thermostatic type, 125 psig rated, cast iron body; balanced pressure thermostatic air vent; stainless steel valve seat, float, brass valve mechanism, and side inlet and outlet. Acceptable Products (0-125 psig): Armstrong Machine Works Hoffman Industrial Specialties Co. Spirax/Sarco Co., Inc. Clark-Reliance Type A Series H, C, or X Type FT Type FT 2.2 FLASH TANKS A. Contractor may field fabricate flash tank or provide one. Tank shall meet requirements as listed on drawings. B. Closed type, welded steel construction, tested and stamped in accordance with Section 8D of ANSI/ASME Boilers and Pressure Vessels Code for 125 psi working pressure; cleaned, prime coated, and supplied with steel support legs. Construct with nozzles and tappings for accessories and pipe connections. KJWW #

3 C. Acceptable Manufacturers: Ace Buehler, Bell & Gossett, Adamson, or Taco. 2.3 LOW PRESSURE CONDENSATE RETURN UNITS (212ºF, Atmospheric vented) A. Units: Consist of factory assembled packaged receiver, strainers, pumps, float switches, control panel and accessories, for duplex operation. B. Receiver: Horizontal, low profile, 3/16" welded steel, suitable for 212ºF condensate, with inlets, outlets, vent, overflow, and drain connections, and lifting eye bolts ASME code stamped for 50 psig. C. Pumps: Rated to pump 212ºF condensate with 1 ft. NPSH, with grease lubricated, sealed ball bearings, bronze impeller, stainless steel shaft, mechanical shaft seal, renewable case rings, coupled to motor, RPM as specified on the drawings, and mounted on common base plate. Refer to Specification Section for additional motor information. D. Control Cabinet: NEMA 12 enclosure, UL listed components, with hinged door, combination fused disconnect magnetic starters with overload relays, Hand-Off-Auto switch, terminal strip, fusible control circuit transformer. Hand-Off-Auto switch, selector 'lead-off-lag' switches, test buttons, high level alarm light, dry contacts for high level alarm, acknowledge button, and alarm horn. E. Control Sequence: Each pump control circuit shall be completely independent of the other. Operate pumps on high level, alternating after each cycle; operate second pump upon failure of first pump and alarm. F. Accessories: Gauge glass, with isolation valves, dial thermometer, pressure gauge on each pump discharge, isolation valves and suction strainer between pumps and receiver, double pole float switches, corrosion inhibitor anode, drain valve. G. Acceptable Manufacturer: Roth Pump, Industrial Steam, Domestic. 2.4 PRESSURE REDUCING VALVE A. Externally pilot operated, spring loaded adjustable pilot operator, single guided equal percentage plug type valve, with cast iron body and bonnet, normally closed diaphragm operator, stainless steel cage and seat for a maximum of 150 psig. Acceptable Manufacturers: Spirax/Sarco Series 25P, Spence Type D, or Hoffman Series SAFETY VALVES A. SV-2: (Steam Service) Spring loaded disc type with bronze, cast iron, or steel body (steel body is required above 250 psig or 406 F), lifting lever, stainless steel disc and nozzle, and side outlet. Capacities ASME certified and labeled for Section I for boilers over 15 psig, Section IV for boilers up to 15 psig, and Section VIII for unfired pressure vessels or downstream of pressure reducing valves. Provide bellows trim where needed to compensate for piping backpressure. Acceptable Manufacturers: Consolidated Series 1900 or 1900/P; Kunkle - Fig. 6030, 6252, 300, or 600; or Keckley - Type 40 or LOCK OUT TRIM A. Provide lock out trim for all quarter turn valves opening to atmosphere installed in steam, condensate, boiler feed water piping, and as indicated on the drawings. KJWW #

4 2.7 ELECTRIC STEAM HUMIDIFIER (IMMERSION TYPE) (ADDENDUM #3) A. Packaged unit, stand mounted, electric steam generator. B. Enclosure shall be an 18-gauge steel frame with cover suitable for finished spaces. Enclosure frame shall include a drip pan with a connection for drain piping. Separate compartments shall house electrical devices. The front exterior of the cabinet shall contain the microprocessor controller s digital keypad. C. Cleanable vaporizing chamber shall be stainless steel with welded seams. The evaporating chamber shall be easily removable. Electrical, water supply, and drain connections shall have unions and plugs to allow convenient removal for cleaning and maintenance. D. Steam outlet on top of tank shall be configured to connect to the piping to the duct mounted dispersion manifold. E. Immersion heaters shall be Incoloy alloy-sheathed resistance type and shall be mounted on the vaporizing chamber s removable cover. F. Water Requirements: The humidifier shall be capable of generating steam from R/O, softened, and tap water. G. Over-Temp Switch: A factory-mounted and wired sensor with manual reset shall sense an over-temperature condition and de-energize heater circuit controls. H. An electric drain valve shall be mounted on the humidifier assembly to allow tank to automatically back flush and drain at the end of a humidification season. Units with 33lbs/hr or greater capacity shall include a flushing/drain pump. I. Humidifier Controls: 1. Microprocessor controller with the following features or functions: a. Makeup water switch control and low water safety shutdown. b. Fully modulating (0% to 100%) control of humidifier outputs. c. Self-diagnostic test at start-up. d. Auxiliary contacts to DDC system. e. Duct mounted humidity sensor. f. Airflow proving switch. Unit shall not operate without proof of airflow. g. Adjustable high limit duct humidity switch. h. A unit mounted keypad capable of monitoring and/or controlling the following parameters: 1) Relative humidity setpoint and actual conditions in space. 2) Relative humidity high level setpoint and actual conditions. 3) Total system demand in percentage of humidifier capacity. 4) Total system output in lbs./hr. KJWW #

5 5) Drain/flush frequency interval and duration. 6) End-of-season drain status. 7) System alarms. 8) Previous fault messages. 9) Operating temperature. 2. Water Level Control: System shall provide for automatic refill, low water cutoff, field-adjustable skimmer bleed-off functions, and automatic draindown of humidifier. a. A thermostatically controlled water valve shall meter an amount of cold water into a mixing chamber to temper 212 F water to a 140 F discharge temperature to sanitary system. b. Stainless steel insulated dispersion tube or manifold to provide required steam distribution. Maximum total absorption distance not to exceed 3-0. c. Acceptable Manufacturers: Dri-Steem VLC, Carel, Vapac, Nortec, or pre-approved equivalent. 2.7 ELECTRIC STEAM HUMIDIFIER (ELECTRODE TYPE) A. Packaged unit, wall hung, electric steam generator. B. Enclosure shall be an 18-gauge steel frame with cover suitable for finished spaces. Enclosure frame shall include a drip pan with a connection for drain piping. Separate compartments shall house electrical devices. The front exterior of the cabinet shall contain the microprocessor controller s digital keypad. C. Replaceable Canister: Shall be polypropylene and contain electric heating elements. D. Steam outlet on top of tank shall be configured to connect to the piping to the ductmounted dispersion manifold. E. Water Requirements: The humidifier shall be capable of generating steam from tap water. F. Over-Temp Switch: A factory-mounted and wired sensor with manual reset shall sense an over-temperature condition and de-energize heater circuit controls. G. An electric drain valve shall be mounted on the humidifier assembly to allow tank to automatically back flush and drain at the end of a humidification season. Units with 33lbs/hr or greater capacity shall include a flushing/drain pump. H. Humidifier Controls: 1. Microprocessor controller with the following features or functions: a. Makeup water switch control and low water safety shutdown. b. Fully modulating (0% to 100%) control of humidifier outputs. c. Self-diagnostic test at start-up. d. Auxiliary contacts to DDC system. e. Duct mounted humidity sensor. f. Airflow proving switch. Unit shall not operate without proof of airflow. g. Adjustable high limit duct humidity switch. KJWW #

6 h. A unit mounted keypad capable of monitoring and/or controlling the following parameters: 1) Relative humidity setpoint and actual conditions in space. 2) Relative humidity high level setpoint and actual conditions. 3) Total system demand in percentage of humidifier capacity. 4) Total system output in lbs./hr. 5) Drain/flush frequency interval and duration. 6) End-of-season drain status. 7) System alarms. 8) Previous fault messages. 9) Operating temperature. 2. Water Level Control: System shall provide for automatic refill, low water cutoff, field-adjustable skimmer bleed-off functions, and automatic drain-down of humidifier. 3. In the absence of a space RH sensor supplied by the ATC, the humidifier supplier shall provide a space humidity sensor to the MC. The MC shall install the sensor or coordinate its installation with the ATC, if applicable, for control by the humidifier s microprocessor controls. I. A thermostatically controlled water valve shall meter an amount of cold water into a mixing chamber to temper 212 F water to a 140 F discharge temperature to sanitary system. J. Stainless steel dispersion tube or manifold to provide required steam distribution. Maximum total absorption distance not to exceed 3-0 K. Supply two replacement canisters with each humidifier. L. Acceptable Manufacturers: Dri-Steem XT, Nortec NHTC, VAPAC LEP, or pre-approved equivalent VACUUM BREAKER A. Spring loaded type selected or adjusted for the minimum possible opening pressure, but never over 11 water gauge. B. Rated for 150 psig and 366 F. C. Acceptable Manufacturers: Johnson VB8, Sarco VB14, Hoffman 62, B&G 26. PART 3 - EXECUTION 3.1 INSTALLATION AND APPLICATION A. Install specialties in accordance with manufacturer's instructions. B. Install full-sized P-traps in the overflow drain piping from condensate return units and extend piping to nearest floor drain. C. Size traps to handle minimum of two and one-half times maximum condensate load of apparatus served, unless noted otherwise. KJWW #

7 D. All traps shall be minimum 3/4" size. E. Install traps with unions or flanges at both ends. F. Provide shut-off valve and strainer at inlet, and check valve and shut-off valve at discharge of traps. G. Provide minimum 10" long dirt pocket of same size as apparatus return connection between apparatus and trap. H. Remove thermostatic elements from traps during temporary and trial usage, and until system has been operated and dirt pockets cleaned of sediment and scale. I. Provide pressure reducing stations with pressure reducing valve, valved bypass, strainer and pressure gauge on upstream side; safety valve and pressure gauge on downstream side. J. Rate safety valves for maximum capacity of largest available trim for pressure reducing valve(s) or maximum capacity of bypass valve(s), whichever is larger, at maximum possible pressure upstream of pressure reducing valve. Set at maximum 20 percent above reduced pressure. K. Terminate safety valves outdoors. Provide drip pan elbow with drain connection to nearest floor drain. L. The size of the bypass valve at pressure reducing stations shall be one size smaller than the pressure reducing valve unless noted otherwise. Provide eccentric reducers as required. The wide-open capacity of the bypass valves shall not exceed the capacity of the relief valve. M. Provide humidifiers with complete standalone control system. Control wiring associated with the humidifier and attached sensors is the responsibility of this Contractor. N. Route humidifier steam hose or piping and provide traps per manufacturer s instructions. END OF SECTION KJWW #