Blackmer’s NG Series natural gas vapor recovery compressor is a single-stage, oil-free reciprocating gas compressor that is designed to handle wellhead operations in continuous duty or remote unmanned locations. It is a good fit for enhancing oil and gas production in the areas of tank-battery vapor recovery, wellhead vapor control, wellhead annulus reduction, and pressure boosting. Standard in all NG models is a full-compartment distance piece. Each NG compressor is constructed with two sets of piston rod seals between the crosshead guide and cylinder area, which form the distance piece. The distance piece provides leakage control and helps prevent oil contamination from any condensates that might be in the gas stream. Connections are provided in the distance-piece for purging, pressurizing or venting as needed. This design also allows the compressors to handle a range of suction pressures, which can be a major consideration in wellhead operations that involve natural gas and methane mixes. Other features of the NG Series compressors, which are to be used in sweet-gas applications only, include: ductile-iron head and cylinder; o-ring gaskets throughout for sealing under all operating conditions; flowrates to 600 MSCFD; maximum of 50-horsepower energy usage; and maximum allowable working pressure of 350 PSIA (24.1 bara).