Water Heater Spec 6-11-18 - 3.9.2 Edited.docx

INCH-POUND

PERFORMANCE SPECIFICATION

HEATER, WATER, LIQUID FUEL

This specification is approved for use by all Departments and Agencies of the Department of Defense.

1 SCOPE

1.1 Scope. This specification covers the performance and acceptance requirements for a liquid fuel burning water heater.

2 APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in Sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirement documents cited in Sections 3 and 4 of this specification, whether or not they are listed.

2.2 Government documents.

2.2.1 Specifications, Standards, and Commercial Item Descriptions (CID’s). The following specifications, standards and CID, form part of the document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2).

Comments, suggestions, or questions on this document should be addressed to U.S. Army Soldier Systems Center, PM Force Sustainment Systems, SFAE-CSS-FP-F, Kansas Street, Natick, MA 01760-5018 or emailed to Joseph.A.Mackoul.civ@mail.mil . Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https://assist.dla.mil .

AMSC N/A FSC 4520

MIL-PRF-32242

SPECIFICATIONS

FEDERAL

A-A-52557 - Fuel Oil-Diesel

DEPARTMENT OF DEFENSE

STANDARDS

FEDERAL

MIL-STD-129 - Marking for Shipment and Storage

MIL-STD-882 - System Safety

MIL-STD-1472 - Human Engineering

MIL-STD-1474 - Noise Limits

COMMMERCIAL ITEM DESCRIPTIONS (CID)

FEDERAL

(Copies of these documents are available online at http://assist.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094)

2.2.2 Other Government Documents and publications. The following Government documents and publications form part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation.

PUBLICATIONS

(Copies of the above publication are available from: Commander, USA CECOM Safety Office, ATTN: AMSEL-SF-SE, Ft. Monmouth, NJ 07703-5024. The web address is www.monmouth.army.mil/cecom/safety/sys_pub/form1183.dot .)

SUPPLY CATALOG

2.3 Non-Government Publications. The following documents form part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents, which are DoD adopted, are those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) cited in the solicitation. Unless otherwise specified, the issue of documents not listed in the DoDISS, are issues of documents cited in the solicitation (see 6.2).

UNDERWRITERS LABORATORIES, INC (UL)

Standard No. 296-Oil Burners Standard No. 372-Primary Safety Controls for Gas-and Oil-Fired Appliances

(Application for copies should be addressed to: Underwriters Laboratories, Inc. 333 Pfingsten Road, Northbrook, IL 60062-2096. The web address is www.ul.com .)

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA Standard No. 31-Standard for Oil Burning Equipment NFPA Standard No. 70-National Electric Code

(Application for copies should be addressed to: National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269-7471. The web address is www.nfpa.org .)

AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME)

Boiler and Pressure Vessel Code, Rules for Construction of Heating Boilers, Section IV, Part HLW, Requirements for Potable-Water Heaters, and Section IX.

(Application for copies should be addressed to American Society of Mechanical Engineers, Three Park Avenue, New York, NY 10016-5990. The web address is www.asme.org .)

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

National Electrical Manufacturers Association (NEMA) Enclosures for Electrical Equipment (1000 Volts Maximum), Type 4 Enclosure.

(Application for copies should be addressed to National Electrical Manufacturers Association, 1300 North 17th Street, Suite 1752, Rosslyn, Virginia 22209. The web address is www.nema.org.)

MANUFACTURERS STANDARDIZATION SOCIETY (MSS) of The Valve and Fittings Industry Inc.

Standard Practice SP-110-Ball Valves, Threaded, Socket-Welding, Solder Joint, Grooved and Flared Ends.

(Application for copies should be addressed to Manufacturers Standardization Society of the Valve and Fittings Industry, Inc., 127 Park Street, N.E., Vienna, Virginia 22180. The web address is www.mss-hq.com .).

AMERICAN SOCIETY OF TESTING AND MATERIALS (ASTM)

ASTM D2156 – Standard Test Method for Smoke Density in Flue Gases from Burning Distillate Fuels.

(Application for copies should be addressed to American Society for Testing and Materials, 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959. The web address is http://www.astm.org.)

NSF INTERNATIONAL

NSF/ANSI 61-2005 – Drinking Water System Components – Health Effects

(Application for copies should be addressed to NSF International, PO Box 130140, 789 North Dixboro Road, Ann Arbor, MI 48113-0140. The web address is http://www.nsf.org .)

Hubble Part No. 2513-Connector.

3 REQUIREMENTS

3.1 First article. When specified (see 6.2), a water heater shall be subjected to a first article inspection in accordance with 4.1.

3.2 Conformance and End Item Examination. Water heaters furnished under this specification shall be subjected to conformance inspection and end item examination in accordance with 4.2.

3.3 Operating Requirements. The water heater shall satisfy the following user-oriented requirements.

3.3.1 Description. The water heater shall operate as specified herein to provide hot water for use with shower units, laundry units, and field kitchens. The heater shall have the capability to heat water with an 89°F ±2°F temperature rise at a rate of 9-gallons per minute (400,000 BTU/hr ±10,000 BTU/hr). Water at ambient temperatures will be provided by an external source using an existing DoD water pump. Electrical power, (120/208 volts, 3 phase Y, 60 hertz, 20 amps), shall be provided by existing DoD generators. All wiring shall be in accordance with NFPA No. 70. The water heater shall operate on JP-8 fuel (MIL-DTL-83133) and diesel fuel (A-A-52555). Fuel will be supplied from a 5-gallon military fuel can or 55-gallon drums through a fuel hose. The water heater construction shall be in compliance with ASME Boiler and Pressure Vessel Code Section IV, Part HLW, and shall pass the ASME Code and have a stamp of approval in accordance with ASME Boiler and Pressure Vessel Code. All water heater surfaces that come in contact with water shall meet the requirements of NSF/ANSI 61-2005. The burner must meet the requirements of UL 296.

3.3.2 Heat output (BTU/efficiency). The water heater shall provide a minimum heat output of 400,000 BTU/hr ± 10,000 BTU/hr operating on diesel fuel, at a minimum system efficiency of 78% or have the capability to heat water with an 89°F ±2°F temperature rise at a rate of 9-gallons per minute.

3.3.3 Water heater electrical power. The water heater shall be 120V, single phase, drawing 10 amps or less on a continuous duty basis. The water heater shall operate on a 3 phase Y, 120/208V AC, 60Hz power supply. The connector from the power supply shall be a 5-wire, 20 amp, 120/208V, 3 phase, Hubble #HBL 2513 connector (NEMA L21-20 configuration). Three wires shall supply the phase, the white wire is to be neutral and the green wire is to be the equipment ground.

3.3.4 Water inlet pressure, flow and temperature. Water shall be supplied via an existing DoD centrifugal water pump at working pressures of 20 psi to 35 psi. Water flow rates will vary from 0 to 15 gallons per minute. Inlet water temperatures will vary from 35F to above 80F.

3.3.5 Outlet water temperature fluctuation. The water heater shall have the capacity to operate at all of the above inlet conditions and control the outlet water temperature. At an inlet water temperature of 70F and a water flow rate of 0 gal/min to 8 gal/min, the outlet water temperature shall meet the 150F requirement with a maximum temperature fluctuation of 20F. To reduce cycling frequency, a minimum water temperature fluctuation of 10F is suggested. It shall be capable of operation in conjunction with the field shower mixing valve. The water heater shall not produce steam.

3.3.6 Fuels. The water heater shall have multi-fuel capability. The water heater shall be safely operated with the fuels listed in Table I at the corresponding environmental conditions, with no operator adjustments required to accommodate varying fuel types. The water heater shall operate on JP-8, DF-1 and DF-2.

3.4 Water vessel. The water vessel must be constructed and contain an ASME stamp of approval once it passes the requirements in the ASME Boiler and Pressure Vessel Code Section IV, Part HLW and Section IX.

3.4.1 External vessel material. The water heater vessel material shall meet the requirements of ASME Boiler and Pressure Vessel Code Section IV, Part HLW. The permitted material choices are 316L and 439 stainless steel, duplex stainless steel with a minimum chromium content of 21%, or any proposed equivalent, which must be approved by the Government in advance. 316L stainless steel material must be passivated to ASTM-A967-2001E1 after all welding on the 316L components is completed. 439 stainless steel material must be mechanically passivated after all welding on the 439 components is completed. If a duplex stainless steel with a minimum 21% chromium content is used, it must be pickled and passivated to remove all heat tint.

3.4.2 Heat exchanger type and material. The heat exchanger shall be a fire tube or tubeless water-jacket design that shall provide for the necessary heat transfer between the combustion gases and the water to be heated. The heat exchanger will be constructed and stamped in accordance with ASME code, section IV, part HLW. Heating surfaces must be non-corrosive in potable water. Acceptable materials are duplex stainless steel with a minimum chromium content of 21%, 316L stainless steel, 439 stainless steel, copper, or any proposed equivalent, which must be approved by the Government in advance. If steel is used, then acceptable lining materials on the waterside surface include a copper lining or a thermally sprayed metallic lining in accordance with HLW-200 capable of withstanding rugged field usage (vibration and shock). The copper lining or thermally sprayed metallic lining must be continuous over all waterside surfaces of the exchanger. The thermally sprayed metallic lining shall be applied to a thickness of no less than 10 mils. The thermally sprayed metallic lining must then be sealed with a fluoropolymer having a submerged surface temperature rating of no less than 500°F. If a duplex stainless steel with a minimum 21% chromium content is used, it must be pickled and passivated to remove all heat tint. Internal heat transfer components shall be accessible for repair or replacement.

3.4.3 Water pressure. The standard military water pump supplies water to the water heater at a pressure range of 20 psi to 35 psi. The water heater must be ASME approved and stamped for an operating pressure of 75 psi. A pressure relief valve, rated at 75 psi, which is in compliance with ASME Boiler and Pressure Vessel Code Part IV, Article 8, shall be provided. The pressure relief valve shall vent in a safe direction and manner. The pressure drop across the boiler vessel shall be no more than 10 psi 5% at a flow rate of 15 gallons per minute.

3.4.4 Water outlet connection. The hot water outlet tank fitting shall be no less than 1” NPT and piped through non-ferrous materials to a 1” male cam lock fitting. The cam lock fitting shall meet Commercial Item Description (CID) A-A-59326. The water vessel shall be equipped with an outlet shut-off ball valve. The ball valve shall be a hand actuated, full port, corrosion resistant metal valve with a blowout proof stem. It shall be pressure rated at a minimum 400 psi WOG (Water-Oil-Gas) non-shock and temperature rated from –20F to 300F. It shall meet the requirements of the Manufacturers Standardization Society (MSS) of The Valve and Fitting Industry Inc., Standard Practice SP-110. The outlet shall have a label identifying it as the “Hot Water Outlet”.

3.4.5 Water inlet connection. The cold water inlet tank fitting shall be no less than 1” NPT and piped through non-ferrous material to a 1 ½” male cam lock fitting. The cam lock fitting shall meet Commercial Item Description (CID) A-A-59326. The inlet shall include an inlet shut-off ball valve. The ball valve shall be a hand actuated, full port, corrosion resistant metal valve with a blowout proof stem. It shall be pressure rated at a minimum 400 psi WOG (water-oil-gas) non-shock and temperature rated from –20F to 300F. It shall meet the requirements of the Manufacturers Standardization Society (MSS) of The Valve and Fitting Industry Inc., Standard Practice SP-110. The inlet shall have a label identifying it as the “Cold Water Inlet”.

3.4.6 Drain capability. The water vessel shall have a drain in the lowest practicable location so the tank may be fully drained per ASME Boiler and Pressure Vessel Code IV, Part HLW, Article 8. The drain valve shall discharge in a safe direction and manner to prevent injury. The drain shall have a minimum 1 ½” NPT diameter outlet and shall include a ball valve on the end with a label identifying it as the tank drain. The ball valve shall be a hand actuated, full port, corrosion resistant metal valve with a blowout proof stem. It shall be pressure rated at a minimum 400 psi WOG (water-oil-gas) non-shock and temperature rated from –20F to 300F. It shall meet the requirements of the Manufacturers Standardization Society (MSS) of The Valve and Fitting Industry Inc., Standard Practice SP-110. The cold water inlet may serve as a drain.

3.4.7 Inlet and outlet on opposite sides of water heater. The cold water inlet shall be located on opposite sides of the water heater from the hot water outlet or at the back of the water heater.

3.4.8 Tank fittings. The tank fittings shall be of the same material as the water vessel or of non-ferrous materials protected from galvanic corrosion with the pressure vessel. 316L and duplex stainless steel fittings can be used interchangeably with 316L and duplex storage tanks provided the assembly is pickle-passivated after all welding is completed.

3.4.9 Water tank capacity. A minimum 20-gallon tank storage capacity has been found to handle the required 45 to 1 turndown ratio, minimize burner cycling, and reduce fluctuations in outlet water temperatures.

3.5 Burner. The burner must be in compliance with UL 296.

3.5.1 Burner type. The burner shall be a pressurizing flame retention burner and shall comply with UL 296. Any other type of burner shall require prior Government approval.

3.5.2 Burner motor. The burner motor shall be continuous duty, split phase with a thermal overload protection device. It shall be totally enclosed or weather protected, and fan cooled. The electrical motor shall maintain safety and performance under all operational, environmental, and rough handling conditions described herein.

3.5.3 Burner cover. The burner shall have a cover for protection from the elements, rough handling and allow it to remain operational in all environmental conditions.

3.5.4 Fuels compatibility. The water heater shall be safely operated with all of the fuels listed in Table I at the corresponding environmental conditions, with no operator adjustments required to accommodate varying fuel types. The water heater shall be capable of operating on JP-8, F-24, DF-1, and DF-2.

TABLE I. Compatible Fuels

Ambient Temperature Range National Stock Number

Military Symbol CONUS

Above +25 F 9140-01-286-5294

DF-2

Above +10 F 9140-01-286-5286

DF-1

Above –60 F 9130-01-031-5816

JP-8

3.5.5 Fuel drain. The water heater shall provide a means to drain residual fuel from the fuel system after operation. It shall be labeled “FUEL DRAIN”.

3.5.6 Efficiency. The burner system shall operate at a minimum of 78% indicated combustion efficiency. Efficiency shall not degrade at increasing elevations up to 8,000 feet.

3.5.7 Smoke. The water heater burner shall not produce a smoke spot number greater than 2 on the Bacharach Scale. Burner adjustments may be made, without replacing components, so the smoke number is not degraded at increasing altitudes up to 8,000 feet.

3.5.8 Burner fuel connections. The fuel connections to the burner shall be corrosion resistant.

3.6 Fuel supply.

3.6.1 Fuel pump capability. The fuel pump shall be capable of drawing fuel from either a standard military 5-gallon can (NSN 7240-01-337-5269) or from a 55-gallon drum with an adapter assembly (NSN 4510-01-214-9139, CAGE: 48406 P/N: 6-1-8285 (only this drawing and its parts list)) without requiring purging. Bleeding of any trapped air in the fuel line and fuel system shall be automatic and without fuel leakage. It shall be capable of drawing fuel through a 10-foot long hose. It shall be capable of drawing to a height of 5 feet above the fuel source.

3.6.2 Fuel hose. The heater shall be supplied with a 10-foot fuel feed hose and a 10-foot fuel return hose. The 0.500 inch diameter hose shall have a nominal inside diameter of 0.406 inches. The fuel hose must meet or exceed the requirements of MIL-DTL-8794. The fittings must meet the requirements of MIL-DTL-5070 and the hose assemblies shall meet or exceed the requirements of MIL-DTL-8795. The fuel hoses shall have an operating temperature range of –65 to +250F. The water heater fuel fitting shall be a male connector with the designation SAE J 514(070102) 3/4 –16 UNF –3A SAE 37 -.5 OD. Both ends of the fuel hose shall be female and capable of connecting to the male fitting noted above.

3.6.3 Fuel filtering /water separation. A fuel-filtering device shall be incorporated to remove foreign particles, suspended ice crystals and separate water from the fuel. The filtering device housing shall be transparent to allow for visual inspection. The filter shall be located within a protected area and shall not break due to freezing of entrapped water. The filter shall be have a 30 micron rating and be capable of processing 30 gallons per hour.

3.6.4 Transport fuel hose coupling. Male dummy couplings shall be provided to secure the fuel feed hose and fuel return hose during transport.

3.7 Controls and enclosures.

3.7.1 Main electrical control box. There shall be one main electrical control box, which shall house all electrical wiring terminals, circuit breakers, relays, switches, alarm indicator lights, audible alarm devices, primary safety control, and wiring diagram. The wiring diagram label shall be permanently attached inside the control box. The main electrical control box shall be weather proof in compliance with NEMA 4. The control box shall be mounted on the heater and located at least two feet above the ground providing easy access for maintenance. The control box shall be capable of being locked to limit access to the internal controls and wiring. The control box cover shall open from the bottom and shall have a positive stop mechanism to protect the cover from detaching or closing when the cover is open.

3.7.2 Controls. Controls, switches and indicators shall provide for safe and efficient operation of the heater and shall be located to be readily identifiable and accessible from the top, during operation of the heater. An indication of control activation shall be provided (e.g., snap feel, audible click, or indicator light illumination). All switches and controls shall be labeled for identification and settings. All of the exposed electrical controls shall be located in a NEMA 4 rated weatherproof box.

3.7.2.1 Primary safety control. The primary safety control shall be located in the main electrical control box and shall be in compliance with UL 296 and UL 372. Burner pre-purge or a valve-on delay of 15 seconds shall be provided to safely evacuate all fuel vapors prior to starting. The flame failure control shall shut off fuel flow to the burner within 3 seconds, if the burner flame goes out during start up or operation. An audible tone shall be sounded and a red indicator light shall be illuminated on the control box to indicate the loss of flame. After shutdown, the control shall lock out the burner and require manual reset from the control panel.

3.7.2.2 Operating water temperature control. The water heater shall be equipped with an adjustable operating water temperature control thermostat that regulates the fuel supply so as not to exceed the rated operating temperature or pressure. The operating water temperature control thermostat shall be factory set at 150F. The operating water temperature control shall have a maximum range of 20F for controlling the water heater ON/OFF cycle. To reduce cycling frequency, a minimum water temperature fluctuation of 10F is suggested. It shall be in a lockable enclosure or in an enclosure that requires a tool to gain access, to deter an operator from changing the factory setting.

3.7.2.3 High temperature limit control. The high temperature limit control shall be in compliance with ASME Boiler and Pressure Vessel Code Section IV, Part HLW, Article 7. The high temperature limit control shall automatically cut off the fuel supply to the burner when actuated by cutting off all electric current flow to the burner. An audible alarm shall be sounded and a red indicator light shall be illuminated on the control box to indicate the high temperature limit has been reached. The high temperature limit control thermostat shall be factory set at 190°F. After a shutdown, the control shall require manual reset and shall allow heater operation once the outlet temperature falls to 20°F below the shutdown temperature.

3.7.2.4 Low water cutoff control. The low water cutoff control shall prevent operation of the burner, sound an audible alarm and illuminate a red low water level light whenever the water level in the heater is below the end of the water level probe. When the water level is raised to the operating condition, the burner shall automatically shut off the red light, stop the audible alarm, and restart.

3.8 Alarms and indicators.

3.8.1 Flame failure alarm. A red "FLAME FAILURE" indicator light located on the control box shall illuminate and provide an audible alarm when the burner controls detect a lack of flame. It shall be labeled “FLAME FAILURE”.

3.8.2 Low water alarm. A red “LOW WATER" indicator light located on the control box shall illuminate and provide an audible alarm when a low water condition is detected in the water heater. It shall be labeled “LOW WATER”.

3.8.3 High temperature limit alarm. A red "HIGH TEMPERATURE LIMIT" indicator light located on the control box shall illuminate and provide an audible alarm when the set high temperature limit is exceeded. The fault code shall repetitively be presented until the ON/OFF switch is positioned to the “OFF” position. It shall be labeled “HIGH TEMPERATURE LIMIT”.

3.8.4 Heater ON indicator. A green “HEATER ON” indicator located on the control box shall illuminate when the heater is turned on and during operation. It shall be labeled “HEATER ON”.

3.8.5 Call for heat indicator. A green “CALL FOR HEAT” indicator located on the control box shall illuminate when the heater is on and calling for heat. It shall be labeled “CALL FOR HEAT”.

3.9 Gages and switches.

3.9.1 ON/OFF switch. A single ON/OFF switch shall be located on the control box to initiate start and stop functions of the water heater. The switch shall be rugged, commercial grade, low profile and NEMA 4 rated. Fuel flow shall stop within 3 seconds when the heater start switch is turned to the OFF position. A green illumination light shall be provided to indicate when power is applied to the heater (see 3.8.4). The green "ON" indicator light shall illuminate when the ON/OFF switch is in the “ON” position. The switch shall be located so that accidental contact by personnel shall not operate the switch.

3.9.2 Flame failure reset switch. As a Threshold (T) a flame reset switch shall be provided on the control to reset the flame failure control. As an Objective (O) the user shall be able to depress the flame failure reset switch without the need to open the control box which would compromise the NEMA 4 rating. The flame failure reset switch shall be NEMA 4 rated. A label shall marked the flame failure reset switch as "FLAME RESET" in accordance to MIL-STD-1472G - 5.4 Labeling. The flame failure reset switch shall be located on a surface of the heater accessible to the user in accordance to MIL-STD-1472G - 5.9.16.11 Functional Reach. The flame failure reset switch shall be low profile to reduce the risk of damage during packing, moving, or other operations different from the require use of the switch.

3.9.3 Water temperature gage. The water heater shall be equipped with a water temperature gage at the hot water outlet that measures and displays water temperature in degrees Fahrenheit. It shall be located so it is easily visible from the cold-water inlet side of the water heater. A means shall be provided to identify 190°F or higher temperature as unsafe.

3.9.4 Water pressure gage. The water heater shall be equipped with an outlet water pressure gage able to operate at discharge temperatures without degradation. It shall measure and display pressure in pounds per square inch (psi) and it shall be readily visible from the cold-water inlet side. A means shall be provided to identify 75psi or higher pressure as unsafe.

3.9.5 Fuel pressure gage. The water heater shall be equipped with a fuel pressure gage. It shall be in a protected location and easily visible. It shall measure and display pressure in pounds per square inch (psi).

3.9.6 Hour meter. An hour meter shall be installed so that it is easily visible without opening any covers. This meter shall record burner hours of operation. Total time range readout of the meter shall be from 0 to 9,999 hours.

3.10 Safety.

3.10.1 Safety design. The water heater shall be designed so that under all conditions of normal use (installation, operation and, maintenance) and under likely fault conditions (including human error), it protects against the risk of electric shock, noise, biological, chemical, temperature, trauma, and other hazards that could cause death, illness, or reduced job performance. All hazards shall be eliminated or reduced to the lowest risk level practicable using methods in the following order of precedence: design; incorporation of safety devices; incorporation of warning devices and procedures/training. Catastrophic or critical hazards shall not rely solely on warnings, cautions, or procedures/training for control of risk. All safety hazards not eliminated through design shall be addressed in the appropriate Technical Manuals. Information regarding hazard avoidance procedures and safety warning labels on equipment shall be included in all manuals. Maintenance Technical Manuals shall address replacement procedures for damaged or missing safety labels. The heater shall be evaluated against SEL Form 1183, System Safety Design Verification Checklist. SEL Form 1183 shall be used as a guideline to address any safety issues that may pertain to the water heater, but have not been specified. The safety design parameters from SEL Form 1183 that are applicable to the water heater shall be reviewed and incorporated.

3.10.2 Sharp edges. Non-functional sharp edges and projections shall be eliminated. All exposed edges, with the exception of components made of sheet metal such as the stack, shall be rounded to a radius not less than 0.03 inches. Sharp edges and corners that can present a personnel safety hazard or cause equipment damage during operation and maintenance shall be rounded to a radius not less than 0.05 inches.

3.10.3 Moving parts. The water heater design shall provide operator protection from all moving parts.

3.10.4 Electrical shock. Necessary electric shock protection shall be incorporated to protect against component damage, electrical shorts, and personnel shock or burns. Personnel shall be suitably protected from access to hazardous voltages (in excess of 30 volts between live parts and/or ground) when setting up, operating, tearing down, during maintenance, or when maintenance covers are opened. The equipment leakage current should not exceed 3.5 milliamperes dc or rms. When excessive leakage currents are required by design or operational requirements, redundant grounding or double insulation methods should be incorporated. Circuit breakers shall be readily accessible without tools for resetting and protected from accidental grounding.

3.10.5 Electrical wiring. The electrical wiring design, protection, methods and materials shall meet the environmental and performance requirements specified herein and shall conform to the National Fire Protection Association (NFPA) National Electric Code, Standard 70. The design and construction of equipment should insure that all external parts, surfaces, and shields are at ground potential at all times during normal operation. Ground connections to shields, hinges, and other mechanical parts should not be used to complete electrical circuits. Any external or interconnecting cable, where a ground is part of the circuit, should carry a ground wire in the cable terminated at both ends in the same manner as other conductors. When the cable plug is mated with the receptacle, the grounding pin should make first – break last contact. Static and safety grounds should not be used to complete electrical circuits. Cables and wires shall be secured with mechanically mounted cable clamps to ensure correct routing, so that cables or wires do not hinder or obstruct equipment maintenance, and to prevent chaffing from contact with adjacent structures. Wires shall be routed so that they do not contact sharp corners, are not pinched between components, and strain relief is provided. Wire ties shall be used to make wiring look neat and professional. Excess wire tie ends shall be cut off close and straight. The presence of external wiring shall be minimized. Fuses shall not be used.

3.10.6 Exhaust outlet. The exhaust discharge stack shall be located and positioned at a minimum height of 6 feet above ground level to prevent the exhaust gases from interfering with the operator during startup or when viewing gages during operation. The exhaust stack shall a minimum diameter of 5 inches and a maximum diameter of 7 inches. The exhaust stack shall be positioned to discharge exhaust gases in a direction that does not endanger personnel. The exhaust stack centerline shall be located at a maximum distance of 20 inches from one or the other narrower end of the water heater. The exhaust stack shall be provided with a rain cap. Provision shall be made for secure stowage of the exhaust stack extension on the heater for packing and movement.

3.10.7 Surface temperatures. Surfaces where prolonged contact is required (handles, controls, etc.) shall be less than 120F for metal, 138F for glass, and 156F for plastic/wood at an ambient temperature of 77F, regardless of condition of operation.

3.10.8 Material safety. Certain chemicals have been identified in the Occupational Safety and Health Act (OSHA) as cancer-producing substances. Before using any materials, which might contain these chemicals, they should be evaluated in accordance with 29 CFR 1910. Consideration of the human toxicity of a substance should be given prior to material selection.

3.10.9 Health hazards. The water heater shall be designed and manufactured to assure water remains potable. The system shall be free of insulating materials such as asbestos. Glass fiber materials shall not be used as the outer surface or covering on cables, wire or other items where they may cause skin irritation to operating personnel. When maintenance procedures require access to glass fibers, such as insulation, a proper caution note should be provided. The release of toxic, corrosive, and explosive vapors shall be prevented.

3.10.10 Environmental hazards. Materials and parts containing mercury shall not be used unless use of mercury is specifically required and approved by the Government.

3.11 Accessories. The water heater shall include the following accessories: a drum adapter for 55 gallon fuel drums (refer to Section 6 - NSN 4510-01-214-9139, CAGE: 48406 P/N: 6-1-8285 (only this drawing and its parts list)), 10 foot or longer fuel feed hose and return hose, exhaust stack, electrode adjustment tool, and a Technical Manual. The fuel hoses shall be labeled “Fuel Hose”.

3.12 Spare parts. Spare parts shall include the fuel filter with gasket, fuel solenoid valve, fuel nozzle, temperature control thermostat, burner cad cell, ignition transformer, one set of burner electrodes, and light bulbs for visual alarms. Spares and a permanent label listing all the spare parts shall be located with the heater in a box that is capable of being locked and is protected from the environment.

3.13 Tools. There shall be no special tools required to repair or maintain the water heater. The water heater shall be capable of complete disassembly and reassembly using common hand tools provided in the General Mechanics Tool Kit.

3.14 Support or ownership requirements.

3.14.1 Size. The maximum cube for the water heater shall be 46.8 cubic feet. The maximum length shall be 55 inches, the maximum width shall be 32 inches and the maximum height shall be 46 inches when the heater is in transport configuration.

3.14.2 Weight. The maximum weight for the water heater shall be 500 lbs. The maximum weight of the water heater and all of its accessories, spares, and on-board tools shall be 520 lbs.

3.14.3 Set up and disassembly time. The water heater shall be capable of being set-up and placed into operation by a crew of two personnel within 30 minutes of arrival on site. Set-up includes making all power connections, water supply connections, fuel supply connections, water fill, fuel fill, pre-operational checks and services, and any other necessary operations. Set-up shall not include establishing the generator (grounding, fueling, etc.) or obtaining fuel or water for the operation. Two operator personnel shall disassemble the water heater to the transport configuration within 30 minutes. The two personnel shall be responsible for reversing all activities associated with set-up in addition to any other operations necessary to achieve the transport configuration. The above constraints apply to all types of climate and weather conditions between 33°F and 90°F. Setup and strike times associated with temperatures above and below this range may be adjusted.

3.14.4 Lifting. The water heater shall be designed so that it can be handled and lifted safely. The weight distribution of the heater components shall provide a safe and stable configuration in all operating positions and during movement. The water heater shall be equipped with an integral forklift access skid to facilitate movement of the water heater. Each forklift pocket shall be a minimum of 3 inches high and 10 inches wide. The forklift access skid shall be designed to prevent damage to other components on the water heater when a forklift is in use. The water heater shall have a handrail and frame designed to assist in manual localized movement and positioning in field conditions and to maximize protection of heater components. The handrail shall encompass the periphery of the water heater to provide protection to components during transport. No components shall extend beyond the protective frame. It shall not impede access to the burner for maintenance or removal. The handrail shall conform to the requirements of MIL-STD-1472, Human Engineering.

3.14.5 Transportability. The water heater shall be capable of being transported by a standard military truck or a two-wheeled trailer restrained to the cargo bed.

3.15 Exterior surface finish. The outside metal surface of the water heater, except those surfaces containing or exposed to high-temperature flue products, shall be coated with a corrosion preventative, (CARC) Chemical Agent Resistant Coating in accordance with MIL-DTL-53072 in Green 383, Color Chip No. 34094, or Tan 686A, Color Chip No. 33446 of FED-STD-595. The use of DOD-P-15328 as a wash primer, then the use of MIL- DTL-53022, Type II as a primer, and top coating all surfaces with a Chemical Agent Resisting Coating (CARC) conforming to MIL-C-53039 or MIL-DTL-64159, Type I has been found to satisfy the exterior surface finish requirement. Surfaces containing or exposed to high-temperature flue products may be coated with a material suitable for the encountered temperatures. Color of the high-temperature coating shall be flat black or shall match the color of the rest of the water heater.

3.16 Mean Time Between Essential Function Failure/ Maintenance Ratio MTBEFF/MR. The quantitative reliability requirement is a MTBEFF of 615 hours. An essential function failure (EFF) shall be scored when an incident results in the loss or significant degradation of an essential function that cannot be quickly (within 15 minutes) corrected by the crew using only on board tools, spares and repair parts. An incident that causes catastrophic or critical hazards shall also be scored as an EFF. The heater shall demonstrate a minimum maintenance ratio (MR) of 0.010 mmh/operating hour (maintenance man hour/operating hour). Maintenance man hours include man hours expended for scheduled and unscheduled maintenance before, during and after services, including time spent for inspection, diagnosis, adjustment of heater, and repair of failed components and assemblies. Preventive maintenance checks and services performed by the operator in 20 minutes or less are excluded.

3.17 Field serviceability (ease of maintenance, spare parts). The water heater shall be designed for ease of maintenance. Modular component use shall be maximized. Minimize the presence of external hoses and components. Standard parts shall be used whenever practicable. Mission critical items, such as the burner, which require rapid maintenance, shall be most accessible. Sufficient and reasonable accessibility shall be afforded for cleaning, inspection, repair and replacement of all critical water heater components. Items requiring most frequent access shall be most accessible. High failure rate items shall be accessible for replacement without moving or removing non-failed items. The water heater shall require use of only those tools in the general mechanics kit specified in Supply Catalog SC 5180 90 CL N26. Test, Measurement, and Diagnostic Equipment (TMDE) required for maintenance shall currently exist in the DoD supply system.

3.17.1 Design for maintenance. The water heater shall be designed for ease of maintenance with general purpose tools (common hand tools) and equipment normally available commercially. Where practical, parts and components shall be located or positioned for rapid and simple inspection and recognition of excessive wear or potential failure. Standard parts shall be used whenever feasible. Oversized captive screws shall be used whenever possible. No small removable screws shall be used on field serviceable components.

3.17.2 Error proof design. The water heater shall be designed to preclude improper assembly or installation. The water heater shall be designed to prevent the interchange of items of a same or similar form that are not in fact functionally interchangeable. Physical measures shall be taken to prohibit improper mounting of units or components. Measures shall be taken to facilitate the identification, orientation, and alignment of cables and connectors.

3.18 Maintenance procedure time. The maximum time required to perform the following maintenance procedures - electrode replacement, fuel nozzle replacement and flame sensor replacement shall not exceed 20 minutes.

3.19 Operation by personnel in MOPP IV protective clothing. The water heater shall be capable of being set-up as specified above, operated, maintained, re-supplied, disassembled (struck), and prepared for movement by personnel wearing the Mission Oriented Protective Posture (MOPP) Level IV Chemical / Biological protective gear (e.g., jacket, trousers, boots, gloves, and mask).

3.20 Preventative Maintenance Checks and Services PMCS. PMCS shall not exceed 20 minutes to accomplish during any climatic condition specified in this performance specification, during daylight or in the dark using a flashlight. Minimum PMCS shall include: inspection of fuel filter for water or dirt contamination and cleaning if necessary; inspect for secure water line connections, electrical connections, fuel supply connections, and exhaust stack connection; inspect for fuel leaks and general condition to permit operation.

3.21 Human factors. The water heater design shall be simple and have an intuitive layout for the user. The water heater shall be designed and/or configured to provide an efficient, straightforward, and effective user interface for all critical install, operate, and maintain (IOM) tasks or procedures. Human factors engineering shall be taken into consideration in the design of the controls. Controls shall be located within the operator’s functional reach and view without the need to assume an uncomfortable or unusual posture. Control design shall facilitate accurate and efficient system operation in accordance with MIL- STD-1472, Human Engineering.

3.22 Labels. The water heater shall have permanent, legible warnings and information labels providing quick and easy identification of assembly, setup, components, spare parts list, safety cautions, operating instructions, electrical wiring diagram, and proper fuels, affixed to the heater, accessories enclosures or panels. The labels shall stay permanently affixed to the water heater under all operating and transport conditions. The labels shall be located on a permanent part of the water heater. Labels shall meet the requirements of MIL-STD-130M. UID (unique identification) marking is required. The labels shall be read quickly and easily from left to right. Label shall be placed on or near the item they identify. Controls shall not obscure labels. Labels shall be located in a consistent manner throughout the water heater system. Labels shall be printed in capitals. All letters shall be black, except when using a black background, then letters shall be white. Label backgrounds shall be red for danger, yellow for caution and black for information. The label letter size and color shall be sufficient to be easily read from a distance of six feet in daylight or with a flashlight when dark. Access panels shall be labeled, identifying the component protected inside.

3.22.1 Operating instructions label. Operating instructions shall include all the information needed to operate the water heater as intended and warn the user against reasonably foreseeable risks of injury to persons. The heading “OPERATING INSTRUCTIONS” or the equivalent shall precede these instructions. Operating instructions shall explain and describe the location, function and operation of each user-operated control of the water heater, and warn against tampering with such devices.

3.22.2 Safety labels. Safety labels shall meet the requirements of ANSI Z535 and shall include lifting requirements, hot surface identification of any surface over 120F, and shock hazards. Cautionary markings shall be legible and visible from the position normally assumed by the operator when starting the water heater or from the position normally assumed for the specific operation involved. A marking intended to inform the user of a risk of fire, electrical shock, or injury shall be prefixed by a signal word “CAUTION” or “WARNING”. The marking shall be in letters not less than 3/32-inch high. The signal word shall be more prominent than any other required marking on the water heater. Additionally, the marking shall contain a statement of the risk involved, for example, “Risk of Electric Shock”. If the discharge fluid is heated, such as the hot water outlet or drain, it shall be marked with the following or equivalent wording, “CAUTION – Hot Discharge Fluid – Do not touch or direct discharge stream at persons”. The water heater shall be permanently marked to indicate the water heater must be disconnected from the power supply when cleaning or servicing is performed. A warning label shall be included, stating, “CAUTION – Risk of Asphyxiation. Use Water Heater Only In a Well Ventilated Area”.

3.22.3 Permanent identification label. The following information shall be marked on the boiler: the manufacturer or vendor name or identifying symbol, a distinctive type or model number, a serial number, a contract number, date of manufacture, the voltage rating, frequency and total current in amperes of the boiler assembly, the firing rate of the burner expressed to the nearest 0.1 gallons per hour, and the grade of fuel.

3.23 Environmental requirements.

3.23.1 Operating temperature range. The water heater shall remain operable in a temperature range of 0F to 120F.

3.23.1.1 High temperature operation. The water heater shall meet the requirements of MIL-STD-810, Method 501.5, Procedure II – Operation at 120F. The water heater will remain operable and show no signs of impairment at a temperature of 120F.

3.23.1.2 Low temperature operation. The water heater shall meet the requirements of MIL-STD-810, Method 502.5, Procedure II – Operation at 0F. The water heater shall remain operational at a temperature of 0F, if the source water is preheated above 32F.

3.23.2 Storage. The water heater shall meet the requirements of MIL-STD-810, Method 501.5, Procedure I – Storage. The water heater and accessories shall remain operable and show no signs of impairment due to storage at 155F for 4 hours daily.

3.23.3 Altitude. The water heater shall meet the requirements of MIL-STD-810, Method 500.5, Procedure II – Operation. The water heater shall operate without loss of performance (78% minimum efficiency and smoke spot less than #2) or component degradation when operated at altitudes of 8,000 feet above sea level. The burner shall have an adjustable air inlet, which can be adjusted by an operator, so that the intake air can be adjusted to prevent smoke number degradation at increasing altitudes.

3.23.4 Wind/rain. The water heater shall meet the requirements of MIL-STD-810, Method 506.5, Procedure I – Blowing Rain. The water heater shall be operable in winds up to 40 mph and rain of 4 inches per hour.

3.23.5 Noise. Noise levels, shall meet the requirements of MIL-STD-1474, Requirement 1, Category D. The noise level shall be measured at a distance 3 feet from the water heater in any direction, at ear level, and shall not exceed 85 dB.

3.23.6 Salt fog. The water heater shall meet the requirements of MIL-STD-810, Method 509.5. The water heater shall be capable of operation after exposure to a 5% salt solution. The water heater and accessories shall show no evidence of peeling, blistering paint, possible electrical shorts due to salt deposits, deterioration, clogging or binding of moving parts, or change in tolerance limits of any internal or external parts. The water heater shall remain fully operational after salt fog testing.

3.23.7 Tilt. The water heater shall remain operational up to a tilt of 10 degrees in any direction.

3.23.8 Sand and dust. The water heater shall meet the requirements of MIL-STD-810, Method 510.5, Procedure I – Blowing Dust and Procedure II – Blowing Sand. The water heater shall remain storable and operational in a sand and dust environment.

3.23.9 Vibration. The water heater shall meet the requirements of MIL-STD-810, Method 514.6, Annex C, Category 4, Composite Wheeled Vehicle (CWV). The water heater shall be transportable in composite wheeled vehicles per Table C-V Vehicles Used for CWV Composite, in Method 514.6 ANNEX C. The water heater shall be capable of transportation over primary roads, secondary roads, and cross-country terrain without damage.

3.23.10 Shock. The water heater shall meet the requirements of MIL-STD-810, Method 516.6, Procedure IV. The water heater and accessories shall remain fully operational after being subjected to drop testing.

3.24 Minimum Run Cycle test.