Fluid injection systems, apparatus, and methods including flexible hoses for wellhead sites

A fluid injection system for wellhead sites, comprising:

• a pump mounted on a trailer, the pump comprising a power end and a fluid end;
• a pump manifold;
• a flexible hose comprising a first end coupled to the fluid end and a second end coupled to the pump manifold, wherein:
• the first end of the flexible hose comprises a first end fitting, and
• the second end of the flexible hose comprises a second end fitting;
• a disconnection device coupled to the first end fitting and the fluid end to couple the first end of the flexible hose to the fluid end of the pump, wherein the disconnection device comprises a plurality of wedges movable by an actuator via a plurality of rods to engage and disengage a shoulder on the first end fitting and a shoulder on the fluid end to couple the first end fitting to the fluid end;
• and
• a rotatable joint coupled to the second end fitting to couple the second end of the flexible hose to the pump manifold.