A method and apparatus assists coupling a loader with a work vehicle. A pre-position instruction signal is generated to pre-position the loader in a predetermined orientation to facilitate the coupling. A forward movement instruction signal is generated for initiating movement of the associated work vehicle 1 towards the loader. A coupled confirmation signal representative of the loader being coupled with the associated work vehicle is received. A forward movement pause instruction signal for pausing the movement of the associated work vehicle towards the loader is generated responsive to receiving the coupled confirmation signal. One or more of the pre-position instruction signal, the forward movement instruction signal, and/or the forward movement pause instruction signal may be automated signals delivered to the work vehicle for executing the commands or images rendered on a human readable display unit for instructing an operator actions to take for coupling the loader with the work vehicle.

A pig pumping unit is provided that allows eight passes to be made simultaneously with a single pumping unit. A single engine is used to drive three or four pumps, each connected into separate pumping units. Two engines may thus be used to drive up to eight pumps in a single trailer.

A fluid valve has a valve plug configured as follows. In order to control a flow rate of a fluid between a first pressure chamber and a second pressure chamber, the valve plug is provided so as to be openable and closable in accordance with a difference between forces generated by pressures in the pressure chambers and resilience of an elastic member. The fluid valve includes an opening motion promoting portion. The opening motion promoting portion promotes an increase in degree of opening of the valve plug after the valve plug has been opened.

A valve spool may include a cylindrical spool body having a spool longitudinal axis, a first spool body end wall and a second spool body end wall disposed axially opposite the first spool body end wall, and a spool outer surface. The spool outer surface may include a first spool guide region proximate the first spool body end wall and having a spool guide region outer diameter, a second spool guide region proximate the second spool body end wall and having the spool guide region outer diameter, and a spool tight clearance region disposed between the first spool guide region and the second spool guide region. The spool tight clearance region may have a spool tight clearance region outer diameter that is greater than the spool guide region outer diameter.

A valve spool may include a cylindrical spool body having a spool longitudinal axis, a first spool body end wall and a second spool body end wall disposed axially opposite the first spool body end wall, and a spool outer surface. The spool outer surface may include a first spool guide region proximate the first spool body end wall and having a spool guide region outer diameter, a second spool guide region proximate the second spool body end wall and having the spool guide region outer diameter, and a spool tight clearance region disposed between the first spool guide region and the second spool guide region. The spool tight clearance region may have a spool tight clearance region outer diameter that is greater than the spool guide region outer diameter.

Provided is a switching valve for use in an analyzer module for switching flow passages of fluids, in which the manufacturing cost is reduced and the life is increased. The valve element is provided with a lower contact portion that comes into close contact with a lower valve seat disposed at a valve body when a valve is closed, and with an upper contact portion that comes into close contact with an upper valve seat disposed at a counter plate when the valve is open. The counter plate has a first recess that is open downward and a second recess that is open toward the first recess and has a smaller horizontal cross-sectional area than that of the first recess, and the upper valve seat is press-fitted into the second recess.

A potential energy store has a hydraulic cylinder in which a piston for storing energy in the form of potential energy of the piston is arranged. A position of the piston relative to the earth's surface can be varied. A pump pumps hydraulic fluid via lines into the hydraulic cylinder such that the piston is raised. A generator converts hydraulic energy of hydraulic fluid, which is displaced out of the hydraulic cylinder as the piston falls, into electricity. A seal arrangement is at least partially arranged between the hydraulic cylinder and the piston. The seal arrangement has a sealing section with a flexible support structure for absorbing the acting forces. The support structure may be coated on one or both sides with a layer which is impervious to fluid and which seals against the passage of fluid or may be impregnated with a solidified material which is impervious to fluid.

A pig pumping unit is provided that allows eight passes to be made simultaneously with a single pumping unit. A single engine is used to drive three or four pumps, each connected into separate pumping units. Two engines may thus be used to drive up to eight pumps in a single trailer.

A pig pumping unit is provided that allows eight passes to be made simultaneously with a single pumping unit. A single engine is used to drive three or four pumps, each connected into separate pumping units. Two engines may thus be used to drive up to eight pumps in a single trailer.

A large scale hydraulic cylinder assembly, disassembly and maintenance system to hoist a hydraulic cylinder in the air, secure one end of the hydraulic cylinder to a tooling piece secured to a movable hydraulically operated torque head and secure a second end of the hydraulic cylinder to a tooling piece secured to a movable tail stock, and thread or unthread nuts to or from both ends of the hydraulic cylinder under high speed low torque and low speed high torque.