Fluid delivery pipe with leak detection

A secondary containment system for fuel delivery comprising:

• a fuel storage tank;
• a first fuel dispenser;
• a first coaxial fuel delivery pipe for delivering fuel from the fuel storage tank to the first fuel dispenser, the first coaxial fuel delivery pipe including an inner pipe for transporting fuel, an outer pipe for containment of fuel leaks, and an interstitial space between the inner and outer pipes;
• a first sump in which the first coaxial fuel delivery pipe is connected to the fuel storage tank;
• a second sump in which the first coaxial fuel delivery pipe is connected to the first fuel dispenser;
• a seal for sealing each end of the interstitial space in the first coaxial fuel delivery pipe;
• a source of pressurized fluid connected to the interstitial space in the first coaxial fuel delivery pipe for delivery of the pressurized fluid to the interstitial space;
• and
• a first pressure sensor arranged to detect pressure within the interstitial space in the first coaxial fuel delivery pipe to determine whether a leak has occurred in the inner pipe of the fuel delivery pipe, the pressure of the fluid in the interstitial space greater than the pressure of the fuel in the inner pile.

A fluid transporting system with leak detection capabilities comprising:

• an inner fluid-carrying pipe for transporting an environmentally hazardous fluid;
• a containment pipe surrounding the inner fluid-carrying pipe and containing any fluid leaks from the inner fluid-carrying pipe;
• an interstitial space formed between the inner fluid-carrying pipe and the containment pipe;
• first and second ends of the containment pipe sealed to the inner fluid-carrying pipe to form a containment chamber for containing any fluid which leaks from the inner fluid-carrying pipe, the containment chamber including the interstitial space;
• a source of pressurized inert fluid connected to the containment chamber;
• and
• a pressure sensor for sensing the pressure of the inert fluid within the containment chamber to determine when a leak has occurred in the inner fluid-carrying pipe, the pressure of the inert fluid within the containment chamber greater than the pressure of the fluid within the inner fluid-carrying pipe.

A coaxial fluid conveying pipe assembly comprising:

• a primary fluid conveying pipe for conveying a fluid;
• a secondary containment pipe surrounding the primary pipe, the secondary pipe including an inner layer resistant to exposure to an interstitial fluid, an abrasion-resistant outer layer, and a reinforcing fibrous intermediate layer disposed between the inner layer and the outer layer, the intermediate layer preventing rupture of the secondary pipe upon pressurization up to at least 75 psi (517 kPa);
• and
• a pressurizable interstitial space defined between the primary pipe and the secondary pipe, the interstitial space pressurized so that the pressure within the interstitial space is greater than the pressure within the primary pipe.