System Components & Operations Flashcards

What is the primary function of a submersible turbine pump (STP) in an UST system?

Answer: To transfer product from the underground tank to the dispenser

The submersible turbine pump is installed inside the UST and pumps fuel upward through the product line to the dispenser.

Which component prevents product from draining back into the UST when the pump shuts off?

Answer: Check valve

A check valve (foot valve) holds product in the line after the pump stops, preventing siphoning back into the tank.

What is the purpose of a hanging hardware assembly at the dispenser?

Answer: To deliver fuel from the dispenser nozzle to the vehicle and allow vapor recovery

The hanging hardware (hose, breakaway coupling, nozzle) is the customer-facing assembly that dispenses fuel and may incorporate Stage II vapor recovery.

A Stage I vapor recovery system is designed to capture vapors during which operation?

Answer: Delivery of product into the UST

Stage I vapor recovery captures gasoline vapors displaced from the UST during product delivery from the tanker truck.

What does a pressure/vacuum (P/V) vent valve do in a UST vent line?

Answer: Opens only when pressure or vacuum in the tank exceeds set thresholds

A P/V valve keeps the vent line normally closed and only opens when tank pressure or vacuum reaches the valve's set point, reducing vapor emissions.

Which fitting allows a tank riser pipe to be accessed for product delivery while remaining normally sealed?

Answer: Kamlock coupling

A Kamlock (cam-and-groove) coupling provides a quick-connect sealed connection between the delivery hose and the tank fill riser.

In a suction-pump UST system, product is pulled to the dispenser by:

Answer: A pump located at or above grade, usually inside the dispenser

A suction system uses a pump mounted in the dispenser or above grade to pull product up from the tank, unlike a pressure system where the STP pushes product.