MEGTEC Customer Connect E-news: Fuel Train Maintenance

Proper maintenance and set-up of your oxidizer, oven or dryer fuel train can ensure your equipment performs as and when expected, minimize energy usage and most importantly, operate safely.

While fuel train configurations and components may vary, these general tips will help prolong the life of your fuel train components and avoid unplanned down time. Always refer to your OEM manual or instructions if available for information on supplied components.

General

• Ensure that the fuel train is well supported and all brackets and hardware are secure. Movement can cause damage or premature wear to the components. Vibration can cause false alarms and inaccurate pressure switch indication.
• Clean dust and debris from fuel train with a soft brush or cloth
• If equipped, ensure the enclosure or weather cover is intact and protecting the fuel train from the elements
• Clean any enclosure vents that may be provided
• If your enclosure is equipped with a fan or blower, be sure it is operating
• Inspect the entire fuel train for corrosion or damage
• Inspect the conduit and tie-off boxes for damage
• Ensure all electrical fittings are tight and the enclosures do not contain moisture
• Check all electrical terminals for tightness and corrosion
• Note and record gauge and switch settings for future reference
• Use caution if pressure washing your fuel train to avoid damaging components
• If painting the fuel train, it is important not to paint over breathers, vents or adjusting mechanisms

Regulators

• Clean any breathers or vents
• Ensure any sensing lines are clear of moisture
• Tighten protective adjusting screw caps to prevent moisture from entering the device
• While the burner is operating, monitor the gas regulator outlet pressure to ensure the pressure remains constant during gas valve cycling
• Replace diaphragms, springs or components as required due to leakage or performance

Pilot Gas Solenoid Valves

• Inspect valve exterior for damage or corrosion
• Solenoid valves should be cleaned periodically. The frequency is dependent upon individual service conditions.  Often a valve will become noisy, sluggish or leak, which indicates cleaning may be required. If disassembled, check internal components for wear. Rebuild kits and coils for most valves are available.
• Ensure 2 pilot solenoid valves are installed. Older systems may only have 1 pilot solenoid valve.

Testing

• Valve leak testing, done with the valve in-line as may be required by local, state or federal governing authorities, is recommended on a regularly scheduled basis.
• Follow manufacturer’s instructions for leak testing procedures
• Safety devices including temperature and pressure switches should be tested to verify their function in the interlock circuits. This testing is recommended to be completed annually at minimum.

Gas Control Valves

• Valves must move freely throughout their full range of operation
• Ensure valve seats or seals are not worn or leaking

Actuators

• Ensure connecting hardware is tight
• Arms and levers must move freely throughout their full range of operation
• Inspect shafts and seals for damage or potential for leakage
• Verify function of cam actuated limit switches
• Many actuators are not user serviceable. Refer to component manufacturer’s instructions for repair or replacement

Strainers

• Strainers should be serviced and any opportunity the equipment is down and gas supplies is locked out. Refer to manufacturer’s recommendations for frequency of cleaning.
• Remove and clean strainers of debris
• Replace if corroded or damaged

Gas vent lines

• Ensure lines are tight and supported
• Line should be open and free of debris or plugging
• Ensure copper or flexible lines are not kinked or damaged

Safety shut off valve

• Operate through full range and shut off
• Check seals and seats for leakage

Gauges

• Leak test threads
• Check that glass is intact and dial is visible
• Check that gauge is accurate and moves when pressure is relieved

Gas unions and piping

• Leak check unions with Snoop or soap mixture. 
• Leak check threads at devices, couplings and joints
• Tighten or replace as needed using the proper sealant
• Re-check as necessary

High and Low gas pressure switches

• Check threads for leakage
• Document switch settings
• Inspect for internal moisture, damage or corrosion

Notes:

1. Fuel train maintenance should be performed by qualified personnel
2. Follow all applicable safety and lock-out procedures prior to performing maintenance procedures
3. All fuel train components must be operated, replaced, installed, and maintained in accordance with applicable federal, state or local codes and in accordance with manufacturer’s instructions.