Abstract: A pump jack has a horse head, a sucker rod connected to the horse head, and a downhole pump connected to the sucker rod. The downhole pump has a reciprocating plunger, a multi-segment barrel, a plurality of sand couplings, and a plurality of wiper couplings.

Abstract: An energy-absorbing bulkhead apparatus includes high-strength roll formed tubular bars, and a bar-supporting sheet to distribute stress from product shifting in large shipping containers during transport. Parts are re-useable and can be quickly installed into the shipping container at selected locations such as near the container's doors. The bars can be swept and/or have deformed/configured ends shaped to engage channel features in side walls of the large shipping container. The bars may define spaced tubes and a tie rod for added strength. For example, the bars can be steel having 120 KSI to 220 KSI tensile strength, and have a cross-section 2-3 inches in depth and 4-6 inches in height, a length of 94 long, and a longitudinal sweep of 6 inches curvature. A flexitank can be positioned in the shipping container and supported by a combination of the bulkhead.