A gas booster for increasing a pressure of a gas comprises: a first gas cylinder (160, 170) comprising: a first chamber (164, 174), and a first piston (166, 176) actuatable within the first gas cylinder, wherein the first piston is configured to draw the gas into the first chamber through a first inlet at a first pressure and to push the gas out of the first chamber through a first outlet at a second pressure that is higher than the first pressure; and a drive comprising an electric motor configured to convert electric energy to linear motion, wherein the electric motor is coupled to the first piston of the first gas cylinder by a first mechanical connection to actuate the first piston, characterized in that the first gas cylinder comprises an adapter (155, 157) at a first end portion of the first gas cylinder and an end cap (163, 173) at a second end portion of the first gas cylinder, the end cap comprising a first inlet check valve (161, 171), a first outlet check valve (162, 172), a first conduit (181, 191), and a second conduit (182, 192), an end of the first conduit being coupled to the first inlet check valve and another end of the first conduit (181, 191) being coupled to the first outlet check valve, the second conduit being coupled to the first conduit and having an outlet to the first chamber, and wherein the end cap is attached to the adapter by a plurality of tie rods (167, 177) that maintain the position of the end cap relative to the adapter. a first gas cylinder (160, 170) comprising: a first chamber (164, 174), and a first piston (166, 176) actuatable within the first gas cylinder, wherein the first piston is configured to draw the gas into the first chamber through a first inlet at a first pressure and to push the gas out of the first chamber through a first outlet at a second pressure that is higher than the first pressure; and a first chamber (164, 174), and a first piston (166, 176) actuatable within the first gas cylinder, wherein the first piston is configured to draw the gas into the first chamber through a first inlet at a first pressure and to push the gas out of the first chamber through a first outlet at a second pressure that is higher than the first pressure; and a drive comprising an electric motor configured to convert electric energy to linear motion, wherein the electric motor is coupled to the first piston of the first gas cylinder by a first mechanical connection to actuate the first piston, characterized in that the first gas cylinder comprises an adapter (155, 157) at a first end portion of the first gas cylinder and an end cap (163, 173) at a second end portion of the first gas cylinder, the end cap comprising a first inlet check valve (161, 171), a first outlet check valve (162, 172), a first conduit (181, 191), and a second conduit (182, 192), an end of the first conduit being coupled to the first inlet check valve and another end of the first conduit (181, 191) being coupled to the first outlet check valve, the second conduit being coupled to the first conduit and having an outlet to the first chamber, and wherein the end cap is attached to the adapter by a plurality of tie rods (167, 177) that maintain the position of the end cap relative to the adapter.