Systems and methods for refueling liquefied petroleum (lp) gas tanks

A liquefied petroleum (LP) gas refueling system for a vehicle, comprising:

• a compressor configured to draw vapor LP gas through a supply line from a storage tank and discharge vapor LP gas through a delivery line to a fuel tank of the vehicle;
• a manifold unit comprising:
• an inlet manifold coupled to the supply line and an intake of the compressor,
• a discharge passage coupled to an outlet of the compressor,
• an outlet passage coupled to the discharge passage and to the delivery line,
• a bypass passage coupled to the inlet manifold and the outlet passage, and
• a bypass valve coupled to the discharge passage and the bypass passage,
• wherein the bypass valve is biased to an open position to transmit vapor LP gas in the discharge passage to the bypass passage, wherein the bypass valve is configured to be actuated to a closed position to isolate the discharge passage from the bypass passage;
• and
• a controller operatively coupled to the compressor and the bypass valve, the controller configured to activate and deactivate the compressor,
• wherein the controller is configured to actuate the bypass valve to the closed position when activating the compressor to discharge vapor LP gas to the delivery line, and the controller is configured to actuate the bypass valve to the open position after a predetermined period of time following deactivation of the compressor.

A method for transferring vapor liquefied petroleum (LP) gas from a storage tank to a fuel tank of a vehicle, the method comprising:

• activating a compressor coupled to a manifold unit to draw vapor LP gas from the storage tank and discharge the vapor LP gas through a discharge passage and an outlet passage of the manifold unit to the fuel tank of the vehicle;
• isolating the outlet passage from the discharge passage and deactivating the compressor in response to detecting a pressure in the outlet passage reaching a predetermined pressure threshold;
• transferring vapor LP gas from the outlet passage to a bypass passage of the manifold unit to depressurize the outlet passage;
• isolating the outlet passage from the bypass passage after a first period of time from initiating the transferring of vapor LP pas from the outlet passage to the bypass passage;
• transferring vapor LP gas from the discharge passage to the bypass passage after a second period of time from initiating the transferring of vapor LP pas from the outlet passage to the bypass passage, wherein the second period of time is greater than the first period of time.