STP (Submersible Turbine Pump) Reference
The STP is the actual pump - located inside the underground storage tank, it pushes fuel up to all connected dispensers. Understanding STP operation and troubleshooting is critical for preventing downtime.
STP vs Dispenser - Critical Difference
STP (Submersible Turbine Pump)
The actual pump, located INSIDE the underground tank. Pushes fuel to ALL dispensers on that product. When it fails, entire product is down.
Dispenser
The customer-facing unit (what most call a "pump"). Contains meters, displays, card readers. Does NOT contain the main pump.
Typical Lifespan
10-15 years
Retail Flow Rate
35-50 GPM
High-Flow Rate
75-160 GPM
Replacement Cost
$3K-6K
Major Manufacturers
Red Jacket (Veeder-Root)
Most common in field. Part of Veeder-Root/Gilbarco family. Excellent parts availability.
Franklin Fueling Systems
Strong in commercial/fleet markets. Known for efficiency. VFD models reduce energy cost.
Wayne (Dover)
Integrated with Wayne dispenser ecosystems. Less common as standalone.
Marley (SPX)
Good for specialty applications. Strong in industrial sector.
Key Components
Motor
Electric motor sealed in housing, operates submerged in fuel. Drives the turbine impeller.
Failure Signs:
Impeller (Turbine)
Spinning vane assembly that creates pressure differential to push fuel upward.
Failure Signs:
Check Valve
Prevents fuel from draining back into tank when pump stops. Maintains prime.
Failure Signs:
Siphon Tube / Riser
Conduit from pump discharge to dispenser. Carries pressurized fuel up from tank.
Failure Signs:
Controller / VFD
Controls pump motor speed and operation. Variable frequency drives optimize energy use.
Failure Signs:
Leak Detection Sensor
Monitors for fuel in sump or containment area. Required for compliance.
Failure Signs:
Frequently Asked Questions
What is an STP (Submersible Turbine Pump)?
An STP is a pump located inside the underground storage tank (UST) that pushes fuel up to the dispensers. Unlike the dispenser (which most people incorrectly call a "pump"), the STP is the actual pump. It operates submerged in fuel and creates the pressure needed to deliver fuel to all dispensers connected to that tank.
How long does an STP last?
A properly maintained STP typically lasts 10-15 years. Motor failure is the most common end-of-life issue. Factors affecting lifespan include: fuel quality, run time hours, electrical quality, and whether it ever ran dry. High-volume sites may see shorter life due to more run hours.
What happens when an STP fails?
When an STP fails, ALL dispensers connected to that product tank will stop dispensing. Unlike a suction system with per-dispenser pumps, a pressure system has a single STP serving multiple dispensers. Complete failure means no sales for that product until replaced - typically a same-day emergency.
How much does it cost to replace an STP?
STP replacement typically costs $3,000-6,000 including the pump, labor, and materials. High-flow commercial pumps cost more. Emergency weekend replacement adds premium charges. Some sites keep a spare STP on hand for critical products due to the sales impact of downtime.
Can I repair an STP or must it be replaced?
Some STP components can be replaced in the field: check valves, controllers, and some impellers. However, motor failure typically requires complete STP replacement since motors are sealed and not field-serviceable. Cost and downtime often favor full replacement over component repair.