Tanks & Tubes Field Guide

1. Check the ATG first — any active alarms? Tank levels? Water levels? Sensor status?
2. Walk the fill area — look at spill bucket lids. Are they damaged, displaced, or sitting in water?
3. Look at the pad surface — staining, cracking, settling near tank access points?
4. Check sump lids — properly seated? Damaged? Signs of water entry?
5. Smell — fuel odor near any containment point is a finding that needs investigation
6. Note the weather — recent heavy rain affects water intrusion in sumps and spill buckets

A containment basin around the fill pipe at the top of each underground tank. When the delivery driver disconnects the hose, any fuel that drips is caught by the spill bucket instead of going into the ground.

• Every tank fill pipe should have one
• They must hold liquid without leaking (that's the whole point)
• They need to be kept clean and dry between deliveries

1. Remove the lid — is the lid intact? Does it seat properly? Is it the right lid?
2. Look inside — water? Fuel? Debris (leaves, dirt, trash)?
3. Check the drain valve (if equipped) — is it closed? Is it leaking?
4. Check the bucket walls — cracks, holes, damage?
5. Check the fill pipe cap — present, sealed, correct type?
6. Check the adaptor / fitting — where the fill pipe meets the bucket. Intact? Sealed?

1. Remove standing water with a hand pump or absorbent
2. Remove debris (leaves, dirt, rocks)
3. If fuel is present — absorb it, contain it, dispose properly, and document
4. Inspect the bucket condition while it's empty (easiest time to see damage)
5. Replace the lid, confirm it seats properly

• STP sump (turbine sump) — around the submersible pump at the top of the tank. Contains the STP, piping connections, and often a sensor.
• Dispenser sump (dispenser pan) — under the dispenser. Contains the shear valve, flex connector, and entry piping.
• Transition sump — where piping changes direction or material. Less common but still needs inspection.
• Under-dispenser containment (UDC) — some sites have a formed containment pan under the dispenser instead of a full sump.

1. Remove the lid carefully — sumps can accumulate vapors. Don't stick your face over the opening.
2. Look for liquid — water? Fuel? How much? How deep?
3. Check the sensor — is there a sensor in the sump? Is it positioned correctly? Is the float free to move?
4. Check fittings and boots — where pipes enter/exit the sump. Boots cracked? Fittings tight?
5. Check the sump body — cracks, holes, damage to the containment itself?
6. Check conduit entries — electrical conduit entering the sump should be sealed. Unsealed conduit = water entry path.

1. Document immediately — photo of the sump condition, note which sump, how much product
2. Identify the likely source — look at every fitting, connection, and seal in the sump. Where is the fuel coming from?
3. Contain — absorb the fuel. Do not pump fuel-contaminated liquid onto the ground.
4. Check the ATG — is there a fuel alarm for this sensor? If not, why not? (sensor out? no sensor installed? wrong threshold?)
5. Escalate per procedure — fuel in containment is a reportable event at most companies
6. Repair the source if you can — tighten a fitting, replace a seal, etc. If it's beyond your scope, document and escalate.

Water in sumps is extremely common, especially after rain. But don't dismiss it — investigate the entry point.

• Check lid condition — damaged or poorly seated lids let rainwater in
• Check conduit seals — unsealed conduit entries are the #1 water path into sumps
• Check pipe boots — cracked or deteriorated boots let surface water in
• Check for fuel sheen — water with a rainbow sheen = fuel present. That changes the situation.
• Remove the water — hand pump or absorbent. Dispose properly.

• Delivery — water in the fuel supply (rare but happens)
• Spill bucket / fill pipe — water enters through a leaking spill bucket or damaged fill cap
• Condensation — temperature changes cause moisture to form inside the tank (more common in tanks that aren't kept full)
• Containment failure — water migrating in through compromised fittings or seals at the tank top

• ATG high water alarm — the probe detects water at the bottom of the tank exceeding the set threshold
• ATG water level reading — check the tank status screen for current water level (even without an alarm)
• Manual stick reading with water paste — apply water-finding paste to a tank stick, lower it to the bottom, and read the color change
• Customer complaints — vehicles stalling, poor performance, water in fuel symptoms

1. Verify the tank and water level — ATG reading + manual stick if needed. Know how much water you're dealing with.
2. Access the tank — usually through the fill pipe or a dedicated access point
3. Use a hand pump or approved extraction method — lower the suction tube to the bottom of the tank
4. Pump slowly — you want to remove water, not stir it up into the fuel
5. Collect into an approved container — never pump onto the ground or into a drain
6. Monitor what you're pulling — water first, then you'll start seeing fuel. Stop when fuel appears.
7. Recheck the ATG water level — confirm the water level dropped
8. Manual stick check — verify with paste that water is below acceptable level
9. Document — how much water removed, before/after levels, suspected source
10. Dispose of water/fuel mixture properly — per Petro Plus and local regulations

Removing the water fixes the symptom. Finding where it came from prevents it from happening again.

• Check the spill bucket — is it holding water? Leaking into the tank?
• Check the fill cap — damaged, missing gasket, not sealed?
• Check tank top fittings — any access point on top of the tank is a potential water entry path
• Check delivery records — did water levels jump after a recent delivery?
• Check site drainage — does water pool around the fill area?

• A tube made of aluminum or other non-magnetic metal inside the fill pipe that extends to near the bottom of the tank (never PVC — drop tubes must be non-magnetic and fuel-compatible metal)
• Fuel flows down through the drop tube during delivery instead of splashing from the top
• Reduces static buildup, turbulence, and vapor generation
• The bottom of the tube sits above the tank bottom — not touching it
• Overfill prevention valves are often integrated into or near the drop tube

• Tank cleaning — drop tube must come out for the tank to be cleaned
• Drop tube replacement — cracked, broken, or wrong-length tube
• Overfill valve service — the overfill prevention device may need inspection or replacement
• Delivery problems — driver reports slow fill rate or can't deliver (possible drop tube obstruction or collapse)
• Inspection / compliance — periodic check of drop tube condition and length

1. Confirm the tank — verify tank number/product. Do not pull the wrong tube.
2. Barricade the area — you're about to have an open tank access
3. Remove the fill cap and any spill bucket hardware as needed
4. Remove the fill adapter — the threaded adapter that the delivery driver connects to. This must come out before the drop tube can be pulled. Note the adapter type and orientation.
5. Note the position/orientation of the drop tube before removing — you need to put it back the same way
6. Pull the tube straight up — it will have fuel on it. Have rags and a container ready.
7. Inspect the tube — cracks, dents, corrosion, buildup inside, length (should reach near the tank bottom)
8. Inspect the overfill valve (if present) — float condition, movement, sealing surface
9. Reinstall or replace — seat properly, correct orientation, confirm it drops to the right depth
10. Reinstall the fill adapter — thread it back in properly, verify it seats and seals correctly
11. Reassemble remaining fill hardware — spill bucket fittings, fill cap, lid
12. Document — what you found, what was replaced, tube condition

The overfill prevention valve (OPV) restricts or stops fuel flow when the tank reaches a set level (usually 90-95% capacity). It prevents the driver from overfilling the tank.

• Float-operated — as fuel level rises, the float restricts the opening
• If it fails open — overfill is possible during delivery. The driver's only protection is the ATG high-level alarm.
• If it fails closed / restricted — driver can't deliver fuel. Slow fill or no fill.
• Test by observation — does the float move freely? Is it stuck, corroded, or damaged?

• The STP sits inside the tank, submerged in fuel, inside the STP sump at the tank top
• An electric motor spins an impeller (the functional element) that pushes fuel up through the piping to the dispensers
• Fuel is pressurized in the line — typically 25-30+ PSI at the dispenser
• The STP runs on demand — when a dispenser is activated, the STP starts and pressurizes the line
• A check valve at the STP outlet holds line pressure when the pump is off

• Red Jacket — very common. Uses a "functional element" (impeller assembly) that is a frequent service item. Typically fixed-speed with a standard contactor/capacitor setup.
• FE Petro (Franklin Fueling) — also widely used. Many FE Petro STPs are variable speed, controlled by a MagVFC (Variable Frequency Controller). The MagVFC adjusts motor speed to maintain target line pressure. See the MagVFC section below for troubleshooting.
• Both brands: the motor sits on top in the sump, the pump/impeller is below in the tank, and the riser pipe connects them.

• STP not running — check power (breaker, contactor, wiring), check if the dispenser is actually calling for fuel
• STP running but low pressure — worn functional element, air in the line, check valve not sealing
• STP cycling on/off — possible leak in the line, failing check valve, or leak detector issue
• STP running continuously — possible leak downstream, bad pressure switch, or control issue
• Noisy STP — cavitation (air), worn bearings, loose mounting. Document what you hear.

• Most STP motors run on 208V (single-phase or three-phase depending on the site and motor type)
• Fixed-speed STPs (Red Jacket, older FE Petro): typically use a contactor and a single capacitor to start and run the motor
• Variable-speed STPs (FE Petro VS2/VS4): controlled by a MagVFC — no traditional contactor/capacitor. The MagVFC is the controller, motor starter, and speed regulator all in one.
• Check the contactor (fixed-speed) — pitted contacts, stuck open or closed, coil not energizing
• Check the capacitor (fixed-speed) — swollen, leaking, or failed capacitor prevents the motor from starting or running properly
• Check wiring in the sump — water intrusion causes corrosion on motor leads and connections

These are NOT alarms. They indicate normal MagVFC operating states.

When a fault occurs, the alarm code displays and an audible alarm sounds. Press the Silence button to mute. Press and hold Silence to cycle through the last 3 faults (F0 = most recent, F1 = second, F2 = third). Press Reset to clear.

The rotary switch sets the target operating pressure. Position 4 (32 psi) is the factory default and a good starting point for calibration.

Factory defaults shown in bold. Lock/tag power OFF before changing any switch.

When two FE Petro STPs share the same product line, the MagVFC supports three operating modes:

• Master/Slave — Master turns on first. When demand increases (more nozzles open), Master calls the Slave to assist. Slave only runs when requested.
• Alternating Circuit — Controllers rotate which one turns on each time the hook signal activates. Only one runs at a time.
• Master/Slave + Alternating — Combination of both. The first-on controller rotates, and additional controllers are called when demand increases.

SW2 — Address switches (Master/Slave)

Master = all SW2 poles OFF. Slaves are addressed per the table below. Up to 31 slaves supported.

Pattern continues for Slaves 9–31 using binary addressing across all 5 poles.

Max wire run (motor wiring)

Exceeding max wire run can cause false OC or LU codes.

• Stage I — during fuel delivery. Vapors displaced from the tank during filling are captured back into the delivery truck instead of venting to the atmosphere.
• Stage II — during dispensing. Vapors from the customer's vehicle tank are captured at the nozzle and returned to the underground tank.
• The goal is to prevent fuel vapors (volatile organic compounds) from escaping into the air
• Required by regulation in many areas — varies by state and local rules

• Extra piping — vapor return lines run alongside product lines. Know which is which.
• Vapor recovery nozzles/hoses — have a vapor return path built in. Heavier and more complex than standard nozzles.
• Dispenser impact — a blocked or failed vapor path can cause nozzle shut-off problems (customer complaint: "it keeps clicking off")
• Vent pipes — the tank vent system interacts with vapor recovery. Blocked or restricted vents cause tank breathing problems.
• Pressure/vacuum in the tank — vapor recovery affects tank pressure balance. ATG may show pressure/vacuum readings.

• Regulations require proof that sumps and spill buckets are liquid-tight
• Testing frequency varies by jurisdiction (often every 3 years, but check local rules)
• A containment that can't hold liquid defeats its purpose — leaks go to the environment instead of being caught
• Failed tests require repair or replacement before the containment can be considered compliant

• Hydrostatic test — fill the sump or spill bucket with water to a specified level and monitor for a set time period. If the level drops, it failed.
• Vacuum test — seal the containment and pull a vacuum. If the vacuum holds, the containment is tight.
• Specific test methods and pass/fail criteria depend on the equipment manufacturer and local regulations
• Testing requires documentation: test method, results, date, tester, pass/fail

• Visual inspection matters — if you see obvious damage (cracks, holes, separated joints), note it. That containment will likely fail a test.
• Don't ignore findings — water or fuel in containment that shouldn't be there is a clue about integrity
• Document what you see — your inspection notes help the testing team focus on problem areas
• Know what's been tested — check site records. If a sump or spill bucket hasn't been tested in years, flag it.