PWS_Attch_S003.pdf

Attachment No. S003 STLI Utilities Maintenance

Example Preventive Maintenance - Boiler

Listed below are suggested frequencies for the various routines and tests to be performed in connection with inspection and maintenance of boilers and could be reflected on submitted Preventive Maintenance Schedules.

Industry Sample

(1) Daily (Boilers in Service) Observe operating pressures, water level and general conditions. Determine cause of any unusual noises or conditions and correct. Perform chemical test on Boiler water to ensure proper treatment levels. (I.e., PH, O2, content, dissolved solids, etc.)

2) Weekly (Boilers in Service)

(a) Test low water fuel cutoff and/or water feeder. Blow down boiler if considerable make-up is used (See 7.05C)

(b) Test water column or gage glass.

(c) Observe condition of flame; correct if flame is smoky or if burner starts with a puff (for oil, observe daily).

(d) Check fuel supply (oil only).

(e) Observe operation of condensate or vacuum pump.

(3) Monthly (Boilers in Service)

(a) Safety valve - try lever test.

(b) Test flame detection devices.

(c) Test limit controls.

(d) Test operating controls.

(e) Sludge blowdown where required.

(f) Check boiler room floor drains for proper functioning.

(g) Inspect fuel supply systems in boiler room area.

(h) Check condition of heating surfaces (for preheated oil installation, inspect more frequently, twice a month).

Annually

(a) Internal and external inspection after thorough cleaning.

(b) Routine burner maintenance.

(c) Routine maintenance of condensate or vacuum return equipment.

(d) Routine maintenance of all combustion control equipment.

(e) Combustion and draft tests.

(f) Safety valve pop test.

(g) Slow drain test of low-water cutoff.

(h) Inspect gas piping for proper support and tightness.

Inspect boiler room J.13.2.7.1.2 P/R/M Standard 45100

STANDARD NO. 45100

EQUIPMENT DESCRIPTION

HEATING SYSTEM - LOW PRESSURE STEAM/HOT WATER; OIL, GAS OR

COMBINATION FIRED CHECK PONT NO CHECKPOINT DESCRIPTION EFS

CRAFT

HOURS

45101 Check combustion chamber for air or gas leaks .059 45102 Inspect and clean oil burner gun and ignition assembly .506 45103 Inspect fuel system for leaks .012 45104 Change fuel filter element for oil burning equipment .066 45105 Check tank fuel level. Check tank, lines and connections for damage .017 45106 Check for proper operational response of burner to thermostat controls .102 45107 Check and lubricate oil burner/blower .061 45108 Check main flame failure protection(gas or oil), include full cycle operation .095 45109 Check pilot flame failure protection for gas burner equipment .033 45110 Check main flame detection scanner on boiler equipped with spark ignition (oil burner) .147 45111 Check flame detection scanner (main and pilot) for boiler Equipped with pilot flame (gas burner) includes full cycle burner check .399 45112 Check electrical wiring to burner controls and blower .061 45113 Clean fire box (sweep and vacuum) .444 45114 Check operation of mercury control switches (i.e. steam pressure, hot water temperature limit, atomizing or combustion air proving, etc.) .110 45115 Check condition of flue pipe damper and exhaust stack .113 45116 Inspect gas pressure regulator for dirt accumulation and clean .029 45117 Check gas pressure regulator for accuracy Using water column pressure gauge .067 45118 Check operation and condition of safety pressure Relief valve. .023 45119 Check operation of boiler low-water cut off (per device). .043 45120 Check pressure gauges. .056 45121 Inspect and clean water column sight glass (or replace). .098 45122 Clean fire side of water jacket boiler. .333 45123 Perform exterior inspection on fire tube boiler (3348-6696 lbs / hr, 100-200 hp). Includes foundation, doors, lagging, leakage’s and area. .383

CHECK PONT NO CHECKPOINT DESCRIPTION EFS CRAFT HOURS

45124 Perform exterior inspection on water tube boiler (16740-33480 lbs. / hr, 500-1000 hp).

Includes foundation, doors, lagging, leakage’s and area. .464 45125 Perform internal inspection on fire tube boiler .671 (3348-6696 lbs/hr, 100-200 hp).

Includes water side metal surfaces, stays and b-faces, fire tube sheds, manholes, plugs, fire side surfaces, ligaments, burners, grates, dampers, etc.

45126 Perform internal inspection on water tube boiler16740-33480 lbs/hr, 500-1000 hp).

(Includes fire side surfaces, drum plates, stays and braces, manholes, piping, furnace tubes, ligaments, flanges, etc. 1.426 45127 Perform hydrostatic inspection of fire tube boiler (3348-6696 lbs/hr, 100-200 hp). .1.464 45128 Perform hydrostatic inspection on water tube boiler (16740-33480 lbs/hr, 500-1000 hp).

2.409 45129 Clean up boiler room (per 100 Sq. ft). ..051 45130 Fill out maintenance record/report. .017

J.13.2.7.1.3 ACME (Excerpt) SECTION TAKEN FROM ACME CODE Section VI Recommended Rules for the Care of Heating Boilers July 1, 1980

7.02 STARTING A BOILER AFTER LAY-UP (SINGLE BOILER INSTALLATION)

A. Procedure When starting a boiler after layup, proceed as follows.

(1) Review manufacturer’s recommendations for startup of burner and boiler.

(2) Set control switch in "Off" position.

(3) Make sure fresh air to boiler room is unobstructed.

(4) Check availability of fuel.

(5) Check water level in gage glass. Make sure gage glass valves are open.

(6) Use try cocks, if provided, to double-check water level.

(7) Vent combustion chamber to remove unburned gases.

(8) Clean glass on fire scanner, if provided.

(9) Set main steam shutoff valve in open position.

(10) Open cold water supply valve to water feeder if provided. Open suction and discharge valves on vacuum or condensate pumps and set electrical switches for desired operation. Vent boiler to remove air when necessary.

(11) Check operating pressure setting of boiler.

(12) Check manual reset, if provided, on low water fuel cuttoff and high-limit pressure control to determine if they are properly set.

(13) Set manual fuel oil supply or manual gas valve in open position.

(14) Place circuit breaker or fused disconnect switch in "On” position.

(15) Place all boiler emergency switches in "On" position.

(16) Place boiler control starting switch in "On" or "Start” position. Do not stand in front of boiler access or cleanout doors. This is a precautionary measure should a combustion explosion occur.

(17) Bring pressure and temperature up slowly. Stand by boiler until it reaches the established cut-out point to make sure the operating control shuts off the burner.

(18) During the pressure buildup period, walk around the boiler frequently to observe that all associated equipment and piping is functioning properly. Check for proper over-the-fire draft.

(19) Immediately after burner shut offs, inspect water column and open each try cock (if provided) individually to determine true water level.

(20) Enter in logbook:

(a) Date and time of startup

(b) Any irregularities observed and corrective action taken

(c) Time when controls shut off burner at established pressure tests performed, etc.

(d) Signature of operator

(21) Check safety valve for evidence of simmering. Perform try lever test. See Exhibit C.

B. Action in Case of Abnormal Conditions.

If any abnormal conditions occur during light-off or pressure buildup, immediately open emergency switch. (Do not attempt to restart unit until difficulties have been identified and corrected.)

OPERATION

A. Water Level

(1) Whenever going on duty, check the water level of all streaming boilers at once.

(2) Check the water gage regularly. The required frequency must be determined by trial. The check should be made when there is steam pressure on the boiler. Close the lower gage glass valve. Then open the drain cock which is on the bottom of this valve, and blow the glass clear.

Close the drain valve and repeat the first test described, with the lower gage glass valve closed. If leaks appear around the water gage glass or fittings, correct the leaks at once. Steam leaks may result in a false waterline and they also may damage the fittings.

(3) If water disappears from the water gage glass, blow down gage glass to see if water appears, then stop the fuel supply immediately. Do not turn on the water feed line. Do not open the safety hand touch temperature. Then add water to 1 in. (25 mm) in the gage glass. Do not put the boiler back into service until the condition responsible for the low water has been identified and corrected.

B. Steaming Pressure.

A common unsafe condition found in steam heating boilers is due to the failure of the safety valve(s) to open at the set pressure. This is usually due to the build up of corrosive deposits between the disk and seat of the safety valve and is caused by a slight leakage or weeping of the valve. The snap-action opening of a safety valve occurs when the boiler steam pressure on the underside of the valve disk overcomes the closing force of the valve spring. As the force of the steam pressure approaches the counter-acting force of the spring, the valve tends to leak slightly and if this condition is permitted to exist, the safety valve can stick or freeze. For this reason, the pressure differential between the safety valve set pressure and the boiler operating pressure should be at least 5 psi (34 kPa), i.e., the boiler operating pressure should not exceed 10 psig (69 kPa). If, however, the boiler operating pressure is greater than 10 psig (69 kPa), it should not exceed 15 psig (103 kPa) minus the blowdown pressure of the safety valve. This pressure differential is also required to help insure that the safety valve will seat tightly after popping and when the boiler pressure is reduced to normal operating pressure. It is very important that periodic testing of safety valve is carried out in accordance with Exhibit C, Par. IV.

C. Blowdown.

Where low-pressure steam boilers used solely for heating and where practically all of the condensate is returned to the often as concentration of solids require. Boilers used for process steam requiring high make-up should be blown down as required to maintain chemical concentrates at the desired level and to remove precipitated sediments. Boilers which are equipped with slow-opening blowoff valves and a quick-opening blowoff cock should have the levers or cocks opening and closing of the slowopening valve has been shut tight, then close the lever valve or cock. Caution: Do not open the slow-opening valve first and pump the lever action valve open and closed as water hammer is apt to break the valve bodies or pipe fittings.

D. Appearance of Rust.

If rust appears in the water gage glass, this is an indication of corrosion that must not be ignored.

Check the boiler water to be sure that the water treatment compound is at proper strength and make sure the boiler is not requiring considerable quantities of make-up water. Check the return line and other parts of the system for evidence of corrosion.

E. Waterline Fluctuation.

A wide fluctuation of waterline may indicate that the boiler is foaming or priming. This may be due to the water level in the boiler being carried too high, or especially in low-pressure boilers, a very high rate of steaming. Foaming may also be caused by dirt or oil in the boiler water.

Foaming can sometimes be cured by blowing the boiler down, draining 2 or 3 in., then refilling a few times. In persistent cases, it may be necessary to take the boiler out of service, drain, and wash out thoroughly as described for a new steam boiler installation, then refill, and put back into service.

F. Abnormal Water Losses.

Where water losses from a steam boiler become abnormal, as indicated by the requirement of large amounts of manually fed make-up, an investigation should be made immediately for cause of loss of water. Proper repair or replacement of parts should be made at once rather than to increase the water treatment to protect the system due to excessive raw water make-up. If the operator cannot determine the cause of the water loss, a component contractor should be contacted.

G. Make-up Water.

When water make-up is needed and neither the boiler nor the condensate tank is equipped with an automatic water feeder, manually add water to the steam boiler.

(1) Use every practical means for excluding oxygen from the boiler water. One source of oxygen is make-up water; therefore, hold make-up to a minimum. If the boiler loses more than 3 in. (76

mm) of water per month, this indicates there probably is a leak in some part of the system. The leak should be found and corrected.

(2) If the system includes a pump for returning condensate or adding feedwater, be certain that the air vent at the receiver is operating properly.

(3) If large quantities of feedwater are required, deaerating equipment is recommended to remove dissolved gases, thereby reducing oxygen corrosion.

H. Low-Water Cutoff.

Check the operation of the low-water cutoff, pump control, and the water feeder if one is installed. Follow the instructions on the tag or plate, attached to each control, to blow down the control regularly as recommended by the manufacturer. Periodically, the low-water cutoff may be tested under actual operating conditions. With the burner operating and the boiler steaming at proper water level, close all the valves in the feedwater and condensate return lines so the boiler will not receive any replacement water. Then carefully observe the waterline to determine where the cutoff switch stops the burner in relation to the lowest permissible waterline established by the boiler manufacturer. If the burner cutoff level is not at, or slightly above, the lowest permissible waterline, in a new installation the low-water cutoff should be moved to the proper elevation, or in an existing installation it should be serviced, repaired, or replaced if necessary.

7.06 REMOVAL OF BOILER FROM SERVICE

A. Procedure.

When a steaming boiler is to be taken out of service at the end of the heating season or for repairs, proceed as follows.

(1) While maintaining boiler water temperature [180 to 200oF (82 to 93oC], drain off boiler water from bottom drain until it runs clear.

(2) Refill to top of gage glass, and add sufficient water treatment compound to bring the treatment up to strength.

(3) When all the dissolved gases are released (approximately 1 hr), shut down the firing equipment by disconnecting the main switch.

(4) For treatment of layed-up boilers, see 9.11F.

B. Cleaning.

When the boiler is cool, clean the tubes and other fireside heating surfaces thoroughly, and scrape the surfaces down to clean metal. Clean the smokeboxes and other areas where soot or scale may accumulate. Soot is not corrosive when it is perfectly dry, but can be very corrosive when it is damp. For this reason, it is necessary to remove all the soot from a boiler at the beginning of the non-operating season, or any extended non-firing period.

C. Protection against Corrosion.

Swab the fire side heating surfaces with neutral mineral oil to protect against corrosion. If the boiler room is damp, place a tray of calcium chloride or unslaked lime in the combustion chamber and replace the chemical when it becomes mushy.

D. Water Level.

Drain a steam boiler back to normal water level before putting the boiler back in service.

E. Periodic Checks.

Check the boiler occasionally during the idle period and make certain it is not corroded.

7.07 MAINTENANCE

A. Cleaning.

Clean the boiler tubes and other heating surfaces whenever required. The frequency of the cleaning can best be determined by trial. A general prediction applicable to all boilers cannot be made. Also, clean the smokeboxes when required.

B. Draining.

A clean, properly maintained, steam heating boiler should not be drained unless there is a possibility of freezing, or the boiler has accumulated a considerable amount of sludge should accumulate in a boiler where little make-up water is added and where an appropriate water treatment is maintained at the proper strength.

C. Protection Against Freezing.

Antifreeze solutions, when used in heating systems, should be tested from year to year as recommended by the manufacturer of the antifreeze which is used. Antifreeze solutions should not be circulated through the boiler proper.

D. Fire Side Corrosion.

Previously in this manual some of the causes of water side corrosion have been stated and procedures recommended to minimize trouble from these sources. Boilers can also corrode on the fire side. Some fuels contain substances which cause fire side corrosion. Sulfur, vanadium, and sodium are among the material which may contribute to this problem.

(1) Deposits of sulfur compounds may cause fireside corrosion. The probability of trouble from this source depends on the amount of sulfur in the fuel and on the care used in cleaning the fire side heating surfaces. This is particularly true when preparing a boiler for a period of idleness.

Preventing this trouble depends also on keeping the boiler heating surfaces dry when a boiler is out of service.

(2) Deposits of vanadium, or vanadium and sodium compound also may cause fireside corrosion, and these compounds may be corrosive during the season when boilers are in service.

(3) The person responsible for boiler maintenance should be certain that the fire side surfaces of the boilers in his care are thoroughly cleaned at the end of the firing season. If signs of abnormal corrosion are discovered, a reputable consultant should be engaged.

E. Safety Valves.

Safety valves on steam boilers should be tested for proper operation in accordance with Exhibits B and C. ASME rated safety valves shall be installed on the boiler where required by jurisdictional regulations. When replacement is necessary, use only ASME rated valves of the required capacity.

F. Burner Maintenance

(1) Oil Burners.

Oil burners require periodic maintenance to keep the nozzle and other parts clean. Check and clean oil line strainers. Inspect and check the nozzle and check the oil level in the gear cases.

Check and clean filters, air intake screens, blowers, and air passages. check all linkages and belts, and adjust as required. Lubricate in accordance with manufacturer's recommendations.

Check pilot burners and ignition equipment for proper flame adjustment and performance.

(2) Gas Burners.

Check gas burners for presence of dirt, lint, or foreign matter. Be sure parts, gas passages, and air passages are free of obstructions. Linkages, belts, and moving parts on power burners should be checked for proper adjustment. On combination oil and gas burners, the gas outlets may become caked with carbon residues from unburned fuel oil after prolonged periods of oil firing and require cleaning. Lubricate in accordance with manufacturer's recommendations. Also check pilot burners and ignition equipment for proper flame adjustment and performance.

G. Low-Water Fuel Cutoff and Water Feeder Maintenance . Low-water fuel cutoffs and water feeders should be dismantled annually, by quality personnel, to the extent necessary to insure freedom from obstructions and proper functioning of the working parts. Inspect connecting lines to boiler accumulation of mud, scale, etc., and clean as required. Examine all visible wiring for brittle or worn insulation and make sure electrical contracts are clean and that they function properly. Give special attention to solder joints on bellows and float when this type of control is used. Check float for evidence of collapse and check mercury bulb (where applicable) for mercury separation or discoloration. Do not attempt to repair mechanisms in the field. Complete replacement mechanisms, including necessary gaskets and installation instructions are available from the manufacturer. After re-assembly, test as per 7.05H.

H. Flame Safeguard Maintenance

(1) Thermal Type Detection Device Check device for electrical continuity and satisfactory current generation in accordance with manufacturer's instructions. After completing maintenance, test as per Exhibit C, IA and IB, and make pilot turndown test as per Exhibit C, IH.

(2) Electronic Type Detection Device Replace vacuum tubes or transistors annually with type recommended by manufacturer. Check operation of unit in accordance with manufacturer's instructions examine for damaged or worn parts. Do not attempt to repair these units in the field. Replacement assemblies are available from the manufacturer on an exchange basis. Test as specified in Exhibit C, IC, ID, IE, or IG for proper type control and make pilot turndown test as per Exhibit C, IH.

I. Limit Control Maintenance.

Maintenance on pressure limiting controls is generally limited to visual inspection of the device for evidence of wear, corrosion, etc. If control is mercury bulb type, check for mercury separation, and discoloration of bulb. If the control is defective, replace it. Do not attempt to make field repairs.

J. Cast Iron Boiler Maintenance

(1) Heating Surfaces. Check the firebox gas passages and breaching for soot accumulation. Use a wire brush and vacuum cleaner, if required, to remove the soot or other dirt accumulations.

(2) Internal Surfaces . If the condition of the water in the boiler indicates that there is considerable foreign matter in it, the boiler should be allowed to cool, then drained and thoroughly flushed out. Remove the blowdown valves and plugs in the front and rear sections, and wash through these openings with a high-pressure water stream. This will normally remove any sludge or loose scale. If there is evidence that hard scale has formed on the internal surfaces, the boiler should be cleaned by chemical means as prescribed by a qualified water treatment specialist.

Steel Boiler Maintenance

(1) Heating Surfaces. Remove all accumulations of soot, carbon, and dirt from the fireside of the boiler. Use flue brush to clean the tubes. Clean breaching and stack as required. Inspect refractory and make repairs as required.

(2) Internal Surfaces.

Blow down as specified 7.05C. If water does not run clear, the boiler should be cleaned. After the boiler is allowed to cool, the cleaning is accomplished by venting, draining the boiler, removing all manhole and handhole covers, and washing the inside of the boiler with a high pressure water stream. Loosen any solidified sludge, scale, etc., with a hand scraper. Start at the top of the boiler and work down. Flush thoroughly after cleaning. Where access is limited or where scale buildup is difficult to remove, it may be necessary to clean the boiler chemically as prescribed by a qualified water treatment specialist.

Use of Flashlight for Internal Inspection.

When practical, use a flashlight in preference to an extension light for internal inspection purposes. If an extension light is taken into a boiler, be sure the cord is rugged, in good condition, and that it is properly grounded. It should be equipped with a vapor-tight globe, substantial guard, and non-conducting holder and handle.

Leaking Tubes.

If one tube in a boiler develops a leak due to corrosion, it is likely that other tubes are corroded also. Have the boiler examined by a capable and experienced inspector before ordering the replacement of one or a few tubes. If all the tubes will need replacement soon, it is preferable and less expensive to have all the work done at one time.

N. Use of Sealant The use of sealant is not recommended in a steam boiler.

O. Maintenance of Condensate Return Systems.

Inspect and clean the strainer ahead of the pump. Drain and flush condensate tank. Check pump packing, float switches, and vacuum switches as applicable. For detailed instructions, refer to manufacturer's maintenance data and recommendations.