4520--Hot Water Heater

SCOPE OF WORK (SOW) Supply and Installation of DHT STV-90030-10D-CU Steam-to-Water Heater with Factory Components ST-90025-3 and ST-90024-78 JD8 1. GENERAL DESCRIPTION Provide all labor, materials, equipment, and supervision required to install two (2) instantaneous DHT STV-90030-10D-CU vertical steam-to-water heater, including steam, condensate, domestic water, controls, and safety devices. The heater shall operate with the Building Management System (BMS), receiving alarm/status signals and water heater settings adjustment through BMS. Name Brand or Equal MUST BE able to connect/communicate with Metasys Johnson Control and BACNET comparable. 2. EQUIPMENT INCLUDED 2.1 Factory-Supplied Components • DHT STV-90030-10D-CU o 10" double-wall copper tube bundle o Vertical ASME shell o Domestic water: 3" inlet / 3" outlet o Relief port: 1" • ST-90025-3 – 10" Steam Valve Assembly o Modulating steam control valve o Actuator and positioner o Steam inlet connection: 3" • ST-90024-78 JD8 Condensate Drain Assembly (75JD8) o 2" condensate drain o F&T steam trap o Check valve o Drain valve and strainer DRAFT -- 1 of 11 -- • Temperature controller and sensors • Control panel (CU package) 2.2 Field-Supplied Components • 1" T&P Relief Valve – Model M15 2031W o 150 psi / 210°F o 730,000 BTU/hr capacity • All piping, valves, fittings, supports, insulation • Electrical wiring and conduit • BMS alarm wiring • Local audible alarm buzzer 3. PRE-INSTALLATION TASKS 3.1 Site Verification • Confirm heater footprint and vertical clearance for tube bundle removal. • Verify floor structure supports equipment weight. • Confirm floor drain availability for relief valve and condensate. • Verify electrical service per DHT submittal. 3.2 Equipment Handling • Inspect equipment for shipping damage. • Rig and position heater in mechanical room. • Anchor unit per manufacturer requirements. 4. MECHANICAL INSTALLATION 4.1 Domestic Water Piping (Potable Side) Cold Water Inlet – 3" Install in sequence: • Full-port isolation valve • Union DRAFT -- 2 of 11 -- • 3" Y-strainer (40–60 mesh) • Pressure gauge • Balancing/flow control valve (if required) • Check valve (if system is closed) Hot Water Outlet – 3" • Isolation valve • Thermometer • Pressure gauge Safety Devices Install the following: • 1" T&P Relief Valve – Model M15 2031W o Set pressure: 150 psi o Set temperature: 210°F o Capacity: 730,000 BTU/hr o Install directly on heater relief port o Pipe discharge full-size to floor drain o No valves allowed in discharge line o Terminate with visible air gap o Support piping to avoid stress on valve 4.2 Steam Piping Steam Inlet – 3" • Install 3" isolation valve • Install 3" Y-strainer • Install 3" drip leg with drain • Connect to ST-90025-3 steam valve assembly • Install vacuum breaker on shell DRAFT -- 3 of 11 -- • Pitch steam line toward heater 4.3 Condensate Piping – 2" Connect to ST-90024-78 JD8 / 75JD8 assembly: • F&T steam trap (factory) • 2" check valve • 2" condensate outlet to return or floor drain • Maintain continuous fall to trap • Provide supports and insulation 5. ELECTRICAL & CONTROLS 5.1 Power – VA Electric Shop Responsibility • Provide dedicated electrical feed to control panel • Bond panel and actuator to building ground 5.2 Control Wiring (BMS Integration Operation) Heaters will be integrated and hardwired into the BMS control panel located near the water heater in Mechanical Bay 8. BMS Dry Contacts • Low-Temperature Alarm (115°F) o Dry contact (NO) → closes on alarm • High-Temperature Alarm (145°F) o Dry contact (NC) → opens on alarm o Activates local audible alarm • Temperature setting adjustments at BMS • Optional: General fault contact Optional Analog Outputs • Hot water temperature (4–20 mA) • Steam valve position (4–20 mA) DRAFT -- 4 of 11 -- 6. STARTUP & COMMISSIONING 6.1 Pre-Startup • Verify all piping is complete and leak-tested • Fill and purge water side • Confirm steam supply valves are closed • Verify electrical connections and grounding 6.2 Startup • Energize control panel • Set outlet temperature to 140°F • Slowly open steam supply valve • Verify modulating valve operation • Confirm condensate trap cycles properly • Check for leaks, hammer, or abnormal noise 6.3 Alarm Testing • Simulate low-temperature alarm (115°F) • Simulate high-temperature alarm (145°F) • Verify BMS receives both alarms • Verify audible alarm functions 6.4 Documentation • Record operating pressures, temperatures, and valve positions • Provide O&M manuals and as-built drawings • Train facility staff on operation and alarm response 7. TRAINING (NEW SECTION) The contractor shall provide comprehensive operator training upon completion of installation and successful startup. Training shall include: DRAFT -- 5 of 11 -- 7.1 System Overview • Review of the DHT STV-90030-10D-CU heater design, components, and operating principles • Identification of all major assemblies: o ST-90025-3 Steam Valve Assembly o ST-90024-78 JD8 / 75JD8 Condensate Drain Assembly o Temperature controller and sensors o Relief valve and safety devices 7.2 Normal Operation • How the heater modulates steam to maintain setpoint • Understanding autonomous control logic • Reading temperatures, pressures, and valve positions • Proper startup and shutdown procedures 7.3 Alarm & Safety Training • Explanation of low-temperature alarm (115°F) • Explanation of high-temperature alarm (145°F) • Audible alarm behavior • How alarms report to BMS • What actions operators should take when alarms occur 7.4 Preventive Maintenance • Cleaning strainers • Inspecting steam traps • Verifying vacuum breaker operation • Checking relief valve discharge • Recommended maintenance intervals 7.5 Hands-On Demonstration DRAFT -- 6 of 11 -- • Live demonstration of system operation • Review of control panel functions • Alarm simulation and response • Q&A session with facility staff…