K20GLT

Overview

The Vulcan Hart K20GLT is a gas-fired, 2/3-jacketed tilting kettle for preparing batch quantities of soups, sauces, stocks, vegetables and other foods. Its listed true working capacity is 20 gallons (76 litres). A crank handle tilts the kettle to help transfer its contents, while the thermostat regulates heat from warm through simmer to boil.

The jacket’s water-level protection interrupts power to the controls and burner when the sensed level is too low. The control panel also includes a vacuum/pressure gauge, power switch and indicator, heat indicator, ignition-failure indicator and water-level sight glass. The K20GLT is one of Vulcan’s K Series gas kettles; related models include the K40GLT and K60GLT.

Key Features

• Tilting kettle: A crank handle turns clockwise to tilt the kettle and counterclockwise to return it upright.
• Thermostat control: Adjusts kettle heat from warm to rolling boil, with simmer and boil settings identified in the operating instructions.
• Jacket monitoring: A vacuum/pressure gauge and water-level sight glass let the operator check jacket conditions.
• Low-water protection: A red indicator identifies insufficient jacket water; the sensing probe interrupts power to the controls and burner.
• Ignition indication: A red ignition-failure indicator identifies a failed burner ignition.
• Draw-off provision: The operating manual directs the operator to check that the draw-off valve is closed before cooking. Draw-off valves are described as optional equipment in the installation manual.

Specifications

• Model: K20GLT.
• Equipment type: Gas, 2/3-jacketed tilting kettle.
• True working capacity: 20 gallons (76 litres).
• Gas input: 100,000 BTU/hr.
• Electrical supply: 120 VAC, 60 Hz, single phase.
• Electrical rating: 5 amps.
• Power connection: Supplied with a 6-foot power cord and 3-prong grounding plug; the manual requires a properly grounded receptacle.
• Listed K20GLT dimensions: A 21.6 in.; B 15.2 in.; C 38.3 in.; D 41.8 in.; E 25.8 in.; F 16 in.; G 21 in.; H 8.2 in.; J 22.3 in.; K 67.1 in.; L 20.7 in.; M 28 in.; N 11 in.; P 15 in.; Q 9.4 in.; R 20 in.; S 28 in. The manual’s dimensional drawing identifies these as lettered dimensions.
• Reservoir jacket refill quantities: The service manual lists 7.0 gallons total fluid volume for the K20GL and K20GLT group, comprising 4.0 gallons of water and 2.75 gallons of heat-transfer fluid. Follow the model manual’s refill procedure and fluid instructions.
• Gas supply guidance: The installation manual suggests 7 in. water column for natural gas and 11 in. water column for propane. The service manual lists nominal supply pressures of 7 in. water column for natural gas and 11 in. water column for propane; its pressure table also lists minimum and maximum values by gas type and service procedure.
• Factory gas configuration: The service manual states that kettles ship set for natural gas at sea-level atmospheric pressure. Gas-type conversion and altitude adjustment require the specified procedures and a combustion analyzer.

Installation & Requirements

Installation must follow applicable local requirements. For Canada, the installation manual identifies local codes, CAN/CGA-B149.1 and CSA C22.2 No. 3 as applicable references. The manual also references ANSI Z223.1 for gas installation and ventilation and NFPA 96 for vapor removal. These are installation-code references in the manual, not claims about a product certification.

Connect the gas supply to the kettle’s gas valve. The gas line must be sized to deliver the nameplate rate without excessive pressure drop, and gas joints and pipe compound must be suitable for propane where applicable. The manual requires a gas shutoff valve ahead of the kettle, clean piping free of obstructions and a leak check using soap and water before lighting. Do not use an open flame to check for leaks. After piping is checked, purge gas piping receiving gas to remove air. The manual cautions against corrugated stainless-steel tubing for commercial gas supply connections and explains that connector length, fittings, kinks or twisting can reduce gas flow.

The service manual states that gas supply pressure must not exceed 14 in. water column (½ psi); higher pressure can damage the gas controls. It calls for an additional line regulator if supply pressure exceeds that limit. The installation manual gives suggested supply pressures of 7 in. water column for natural gas and 11 in. water column for propane. Confirm the correct requirements for the unit and its serial-number-specific service procedure.

Plug the supplied power cord directly into a properly grounded three-prong receptacle. Do not remove the grounding prong. The service manual advises using a standard 120 VAC outlet rather than a GFCI where possible for units with electronic ignition, because some GFCI circuits may nuisance-trip. If a GFCI connection is necessary, it identifies Pass and Seymour part 913053 as approved by engineering for electronic ignition systems.

Position the kettle with enough space for operation, service access and the cover when raised. The manual specifies a minimum clearance of 2 in. at the rear and 6 in. at each side from both combustible and non-combustible construction. Do not obstruct airflow into or around the kettle; the manual identifies this airflow as necessary for gas combustion and ventilation. It also notes that the draw-off valve should be located near a floor drain. Level the kettle with the cover open by adjusting its feet until the rim is level left-to-right and front-to-rear.

Operation

Checks before operation

With the kettle cold, the vacuum/pressure gauge should read 20–30 in. Hg below zero. A higher reading indicates air in the jacket; use the manual’s venting procedure. Check that the gas supply valve is on and inspect the sight glass. The operating manual says the water level should be near the middle of the sight glass; if it is below one-quarter of the glass or the low-water light is illuminated, add water using the jacket-filling procedure. Use distilled water only for refilling the jacket. Check the rear flue for obstructions before operating.

Heating and cooking

Turn the power switch on and set the thermostat to maximum to start. The heat light illuminates while heat is being called for. If the ignition-failure light comes on, switch the unit off, wait five minutes, then switch it on again as directed in the operating manual. For preheating, set the thermostat to Simmer/Boil and wait for the heat light to cycle off. Before cooking, confirm that the draw-off valve is closed, then select the desired warm, simmer or boil setting and add the food. The manual recommends putting milk- or egg-based foods into a cold kettle before cooking to reduce sticking from sudden contact with a hot surface.

Tilting and shutdown

Before tilting, set the thermostat to minimum and turn the power switch off. Turn the crank handle clockwise to tilt and counterclockwise to return the kettle upright. The manual notes that the low-water indicator can come on normally while a tilting kettle is tilted; it should not be lit with the kettle upright during operation. For daily shutdown, set the thermostat to minimum, switch off, then clean and dry the kettle. For an extended shutdown, turn off the manual gas supply valve and disconnect power.

Cleaning & Maintenance

Before cleaning or servicing, disconnect electrical power and follow lockout/tagout procedures. The kettle and its parts can be hot, so use care. Before first use, remove protective metal oils from the interior and surface parts with a non-corrosive, grease-dissolving commercial cleaner, following the cleaner maker’s directions. Rinse thoroughly with warm water, drain the cooking area and wipe it dry.

For stainless-steel care, the manual recommends suitable non-chlorinated, chloride-free cleaners at their recommended concentrations. Do not use steel pads, wire brushes or scrapers. For stubborn stains and discoloration, it lists cleaners to be rubbed in the direction of the polish lines. Wipe off cleaning agents and standing water promptly. The manual also lists mild soap and water for routine cleaning and advises soft cloths or sponges for applying cleaners.

Maintain the reservoir jacket with distilled water only; the user manual warns that tap water can damage the jacket and void the warranty. When refilling, the service manual specifies a water and heat-transfer-fluid mixture and gives the K20GLT-group volume in the specifications above. Its refill instructions say to place the kettle upright, add the mixture slowly through the fill port, and stop when the sight glass is one-third full. The user manual’s pre-operation check describes the operating water level as near the middle of the sight glass. Check the appropriate procedure in the manuals for the task being performed. After filling, the service procedure calls for venting the jacket, checking the low-water indicator and verifying proper operation.

If the kettle is equipped with a draw-off valve, follow the manual’s valve-specific cleaning directions. For the plug-style valve, remove the retaining ring and washer, lift out the plug, wash the parts with mild soap and water, rinse and air-dry. Avoid scratching, denting or damaging the plug; keep each plug with its original valve body if multiple kettles are in use. For reassembly, the manual specifies applying PetroGel lubricant to the plug face, aligning the washer key with the plug groove and hand-tightening the retaining ring. The compression-style valve has separate cleaning and assembly instructions in the manual.

Troubleshooting

• Low-water light illuminated: The indicator means jacket water is insufficient and the safety circuit has interrupted power to the controls and burner. Check the sight glass and follow the jacket-filling procedure using distilled water. The service manual identifies the low-level cut-off probe and control as part of this protection system.
• Low-water light comes on while tilting: The operating manual says this can be normal when the kettle is tilted. The light should not be on with the kettle upright during operation.
• Ignition-failure light illuminated: Switch the kettle off, wait five minutes and switch it on again. If ignition still fails, stop and have a qualified service technician diagnose the ignition system.
• Gauge does not show the specified cold vacuum: The manual says a reading other than 20–30 in. Hg below zero indicates air in the jacket; follow its venting procedure.
• Insufficient heating or burner problems: The service manual directs trained technicians to use the applicable serial-number procedure to check gas supply, blower operation, ignition and combustion. It specifies manometer and combustion-analyzer checks and says gas work must follow lockout/tagout and leak-check procedures. The service manual is intended for trained service technicians, not unqualified operators.

Applications

The K20GLT’s 20-gallon working capacity and tilting kettle format suit batch cooking and transfer tasks in institutional, restaurant, catering and other commercial foodservice kitchens. Typical uses include cooking soups, sauces, stocks and vegetables. The thermostat settings support warming, simmering and boiling, while the crank-operated tilt helps pour prepared food into a receiving container.