An artefact which is intended to operate and supply power to an artefact (instrument) with an edged or pointed end for making holes in hard substances by revolving or by a succession of blows.

An artefact which is intended to operate and supply power to an artefact (instrument) with an edged or pointed end for making holes in hard substances by revolving or by a succession of blows.

A rigid metal conduit that provides the high-pressure pathway for drilling mud to travel approximately one-third of the way up the derrick, where it connects to a flexible high-pressure hose (kelly hose).

A physical object that provides rotational or reciprocating energy to driven equipment.

A physical object that provides rotational or reciprocating energy to driven equipment.

A power transformer of which the magnetic circuit and windings are not immersed in an insulating liquid.

A power transformer of which the magnetic circuit and windings are not immersed in an insulating liquid.

A physical channel that acts as a conduit for fluids, gases, pipes or cables to transfer from one point to another.

A physical channel that acts as a conduit for fluids, gases, pipes or cables to transfer from one point to another.

A 'detector' for measuring the velocity, mass, charge, flight direction, and number of dust particles in space.

A 'detector' for measuring the velocity, mass, charge, flight direction, and number of dust particles in space.

An electrical conductor that is a busbar used for earthing.

An electrical conductor that is a busbar used for earthing.

An electrode, which is the conductive part, that can be embedded in a specific conductive medium, e.g. concrete or coke, in electric contact with the Earth.

An electrode, which is the conductive part, that can be embedded in a specific conductive medium, e.g. concrete or coke, in electric contact with the Earth.

A detector intended to detect a leakage current to earth.

A detector intended to detect a leakage current to earth.

An electrode that is an earth electrode consisting of a metal plate buried in the ground.

An electrode that is an earth electrode consisting of a metal plate buried in the ground.

An electrical conductor that is used to connect the earthing system to structure.

An electrical conductor that is used to connect the earthing system to structure.

A resistance through which the neutral pint of a supply system is earthed, in order to limit the current that flows on the occurrence of an earth fault.

A resistance through which the neutral pint of a supply system is earthed, in order to limit the current that flows on the occurrence of an earth fault.

A control valve that uses a rotating disc as closing element, and with a design that causes the disc to take a slightly eccentric path during actuation.

A control valve that uses a rotating disc as closing element, and with a design that causes the disc to take a slightly eccentric path during actuation.