OPERATING AND MAINTENANCE MANUAL FOR STEAM FIRED WATER HEATER ELECTRIC HEATER COMPANY BASE MODEL “ ST and STH ”
HUBBELL ELECTRIC HEATER COMPANY P.O. BOX 288 STRATFORD, CT 06615 PHONE: (203) 378-2659 FAX: (203) 378-3593 INTERNET: http://www.hubbellheaters.com/ -- IMPORTANT -Always reference the full model number and serial number when calling the factory. WARNING / CAUTION 1. Tank is to be completely filled with water and all air is to be vented before energizing. 2. Due to the rigors of transportation, all connections should be checked for tightness before heater is placed in operation. 3.
TABLE OF CONTENTS SECTION TITLE PAGE # I GENERAL DESCRIPTION AND CONSTRUCTION 9 II INSTALLATION AND OPERATION 13 III SCHEDULED MAINTENANCE AND SERVICING 18 IV ADJUSTMENT OF TEMPERATURE REGULATORS 25 V TROUBLESHOOTING 28 VI MISCELLANEOUS CHARTS AND FORMULAS 30 3
NOMENCLATURE FOR PARTS 6
NOMENCLATURE FOR ACCESSORY PARTS 7
SECTION I - GENERAL DESCRIPTION AND CONSTRUCTION GENERAL DESCRIPTION This book describes a packaged steam powered water heater that is a stationary, self-contained unit. The complete assembly on a standard unit consists of the storage tank, immersion heating coil, steam regulator, steam drip trap, condensate trap, steam strainer, condensate strainer, vacuum breaker, and an ASME rated combination temperature and pressure safety relief valve. Optional equipment may be supplied with your unit.
3. Stainless Steel – Stainless steel (type 304, 316, or 316L) is well suited for high purity applications requiring a corrosion resistant tank with minimal leaching of impurities into the water. Well suited for process, RO, and DI water systems in the pharmaceutical, food, and electronic industries. TANK CONNECTIONS The heater is supplied with separate cold water and hot water connections. A connection is provided for mounting a combination safety temperature and pressure relief valve.
STEAM OPERATING CONTROLS The steam operating controls are factory selected, sized, piped, and tested to ensure reliable operation. Steam controls can be shipped loose, upon request, for in the field installation by others. All steam components are factory plumbed with schedule 40 black iron pipe and ready for steam and condensate connections. A cast iron ‘Y’ strainer with 20 mesh screen protects the steam controls and coil from dirt and debris in the steam supply.
OPTIONS The following optional features may be included in your water heater. Reference the drawing specific to your heater for further details. Single Solenoid Safety System A single solenoid safety system closes the steam supply to the control valve should the temperature in the tank reach the high limit set point. This option requires 120-volt, 5-amp electrical service.
SECTION II – INSTALLATION AND OPERATION WARNING / CAUTION DO NOT TURN ON THE STEAM SUPPLY to this unit until heater is completely filled with water and all air has been released. If the heater is NOT filled with water when the steam supply is turned on, damage to the heating coil may result.
3. Install the combination temperature and pressure safety relief valve in the tapping provided. Note that this is required by law for safety considerations. Outlet to floor drain Install into provided tapping Manual Release Lever Temperature Probe 4. Install a relief valve overflow pipe to a nearby floor drain. CAUTION: No valve of any type should be installed between the relief valve and tank or in the drain line. HOOK-UP OF AIR AND WATER OPERATED CONTROLS 1.
Typical Piping Diagram ELECTRICAL INSTALLATION 1. If the unit is furnished with a pilot or self contained control valve, no external source of power is required for the valve. (See enclosed operation and maintenance manual for specific valves). 2. If the unit is furnished with an air or electric control valve, see enclosed drawings for required connections. (See enclosed operation and maintenance manuals for specific valves). 3. Torque screws per torque chart included in Section VI. 4.
FILLING THE HEATER 1. Begin with all steam, condensate, and water valves closed. 2. Open the isolation valves on the integral circulator line ,if supplied. 3. Open cold water valve, fill unit with cold water. Lift lever on relief valve to relieve trapped air. Release relief valve lever when all traces of air have been vented from the unit. Leave cold water valve open. STARTUP 1. Turn pump switch to the “ON” position, if supplied.
SHUTDOWN 1. Close valve to heating medium and air supply valve, if air operated controls are furnished 2. Disconnect all electrical power to unit. 3. Close hot water outlet valve. 4. Close building recirculation inlet valve, and shut down building circulation pump. 5. Close cold water inlet valve. 6. Turn off pump, if supplied. 7. Drain unit by lifting lever on relief valve to vent tank, then slowly open drain valve.
SECTION III - SCHEDULED MAINTENANCE AND SERVICING WARNING / CAUTION Before performing any maintenance procedure, make certain steam supply and electrical power supply is OFF and cannot accidentally be turned on. QUARTERLY INSPECTION 1. Monitor thermostat a. Let water heater completely heat to a designated thermostat setting. b. After thermostat satisfies (that is, when the thermostat actually clicks off), draw water from heater. c.
11. Convection packages may be equipped with an integral circulator. This circulator should be serviced per the enclosed pump O&M manual. 12. The unit as well as all strainers should be blown down regularly to remove any trash, and sediment that may have accumulated. 13. If unit is supplied with anode rod, it shall be inspected for excessive wear. 14. Packing on valves and regulators should be checked for leaks and repaired or replaced as necessary. 15.
occur at this point, but as the gasket seats, leaking will gradually stop). After leaking has stopped, turn the nut approximately 1 revolution. At this point there may be some miner seepage, wait a few minutes to see if this seepage stops. If seepage continues drain the tank, inspect the manhole ring, and cover for any damage, (repair or replace as required) Repeat the above procedure using a new gasket.
SINGLE SAFETY SOLENOID SYSTEM (if installed) 23
DOUBLE SAFETY SOLENOID SYSTEM (if installed) 24
SECTION IV – ADJUSTMENT OF TEMPERATURE REGULATORS 1. The spring tension on temperature regulators is adjusted at the factory to meet design conditions. However, design conditions may vary from actual operating conditions and readjustment might be required on this job. 2. Whenever possible, Hubbell uses “fail safe” regulators. This means that if the controlling medium, such as air or water is lost, the valve will close under it’s own spring tension. 3. ADJUSTMENT OF 2-WAY AIR OR WATER OPERATED VALVES a.
f. Apply air pressure to valve diaphragm so that stem halves are aligned and re-connect stem halves. g. If valve will not open with air on the diaphragm, spring tension should be decreased. h. Adjustment is essentially the same as if spring tension were increased except the adjustment screw is turned in the opposite direction. 5. ADJUSTMENT OF PILOT OPERATED VALVES a. Pilot operated valves such as Spence or Spirax/Sarco are not fail safe.
c. Spence Valves: There is no main spring adjustment on Spence Valves. To set temperature on the water heater: (1) Turn pilot spring adjustment “A” clockwise until all tension is off the spring. (2) Refer to unit start-up section and start unit except for thermostat setting. (3) Turn spring adjustment “A” counter-clockwise until the wheel is firmly against the spring. (4) Continue to turn wheel “A” one 360° turn or until steam begins to pass thru the valve. (5) Allow unit to heat until the valve closes off.
SECTION V – TROUBLESHOOTING (See separate component O&M for additional details.) Symptom Gradual loss of heating capacity. Probable Cause Tubes are fouled. Corrective Action / Remedy Clean tubes per Section III, annual scheduled maintenance. Excess silt in bottom of tank. Drain and flush tank per Section III , annual scheduled maintenance. Air or water leak in Repair or replace per separate O&M. temperature control. Ruptured diaphragm on air Repair or replace per separate O&M. or water operated valve.
Excessive vibration. Water hammer. High rate of flow beyond design conditions. Under sized piping to the unit. Defective steam trap. Consult factory. Undersized condensate lines. Re-pipe condensate line using proper sized lines. Increase slope on condensate lines. Insufficient slope on condensate lines causing backup. Re-pipe lines to unit using proper sized lines. Repair or replace per separate O&M.
SECTION VI – MISCELLANEOUS CHARTS AND FORMULAS TORQUE VALUES 18-8 S/S BOLT SIZE IN.-LBS. 4-40 4-48 5-40 5-44 6-32 6-40 8-32 8-36 10-24 10-32 1/4-20 1/4-28 5/16-18 5/16-24 3/8-16 3/8-24 7/16-14 7/16-20 1/2-13 1/2-20 9/16-12 9/16-18 5/8-11 5/8-18 3/4-10 3/4-16 7/8-9 7/8-14 1-8 1-14 30 5.2 6.6 7.7 9.4 9.6 12.1 19.8 22.0 22.8 31.7 75.2 94.0 132 142 236 259 376 400 517 541 682 752 1110 1244 1530 1490 2328 2318 3440 3110 BRASS IN.-LBS. 4.3 5.4 6.3 7.7 7.9 9.9 16.2 18.0 18.6 25.9 61.5 77.
METRIC CONVERSIONS 31
