1091.
11].
1112.
1118.
10
Numerical control systems, as follows-
(4) Numerical control systems specially designed for controlling co-ordinated simultaneous (contouring and continuous path) machining movements in a machine tool in 3 or more axes; and machine tools designed for or equipped with such controls;
(b) Numerical control servo-driven measuring or gauging machines specially designed for measuring at any point of the contour the dimensional shape and contour charae teristics of two- or three-dimensional objects including objects of revolution.
GROUP B.
CHEMICAL AND PETROLEUM EQUIPMENT.
Cas liquefying equipment, as follows-
(<) Equipment specially designed for the production in liquid form of air, oxygen, nitrogen and/or argon and producing ton or mers per day of gas in liquid form, except planta not capable of producing more than 25% of their total daily product as extractable gas in liquid form;
(b) Equipment for the production of liquid hydrogen, except plants with a capacity of less than 4 tons per 24-hour day and not designed for, or capable of, the production of hydrogen slush;
(e)
Liquid fluorine producing equipment; (d) Equipment for belium as follows-
() Equipment for the separation of belium From natural gades; and
(1) Equipment for the production of liquid helium, except equipment which has a capacity of no more than 20 lines per hour.
Plant and equipment specially designed for the production and/ or concentration of deuterium oxide.
Equipment for the production of military explosives and solid propellants, as follows-
(4) Complete installations;
(b) Specialized components;
(c) Nitrators: continuous types;
(d) Pumps and valves,
1129.
Vacuum pumps, as follows
(a) Ion vacuum pumps (ie. those using the principle of ionization) except those having pumping speeds of less than 800 litres of hydrogen per second at a pressure of 10-6 millimetres of mercury or more (ie. 10-5, 10~*, cc.); (b) Turbo-molecular pumps having a higher capacity than 2,000
litres of nitrogen per second;
1131.
1133.
4133.
1142.
1145,
11
(c) Diffusion pumps rated for unbaffled pumping speeds of more than 50,000 litres of nitrogen per second at pressures of 10-4 millimetres of mercury or less;
(d) Cryopump systems, not elsewhere specified (ie, systems in which the circulation of liquefied gas is used to achieve a vacuum, either static or dynamic, by lowering the tempera- tore of the environment);
(e) Specially designed parts. controls and accessories for the
above pumps.
Pumps (except vacuum pumps) delivering liquids separately or în combination with solids and/or gases and having any of the following characteristics—
(@) Designed to move molten metals by electromagnetic forces; (6) Specially designed for operation at temperatures below −274°F. (-170°C), except pumps with a flow rate of 100 gallons per minute or less which are not designed for operation at temperatures below -328°F. (-200°C);
(c) Having all flow contact surfaces made of any of the follow
ing materials
(0) 90% or more tantalum, titanium of zirconium, either separately or combined;
(i) 30% or more cobalt or molybdenum, either separately or combined;
(i) Polytetrafluoroethylene; polytrifluorochloroethylene.
Valves, oocks and pressure regulators, not elsewhere specified as follows-
(0) Specially designed
operate at temperature below -274°F, (-170°C.), except those of 2 inches diameter or less specially designed for operation at temperatures from —274°F. (—170°C) to −328°F. (~200°C), "or
(6) Having all Bow contact surfaces made of any of the
following materials-
(1) 90% or more cantalum, titanium or zirconium, either separately or combined;
(ii) 50% or more cobalt or molybdenum, either separately or combined:
(ii) Polytetrafluoroethylene; polytrifluorochloroethylene.
Valves less than 3 centimetres in diameter, with bellows seal, wholly made of or lined with aluminium, nickel, or alloy con- Laining 60% or more nickel, either manually or automatically operated, and with other than metal to metal seats.
(See also Atomic Energy List item d.E. 27)
Pipe and tubing made of, lined with or covered with polytetra- Auoroethylene or polytrißuorochloroethylene,
Containers, jacketed only, for the storage or transportation of liquefied gases at temperatures below -274°F (-170°C) including mobile units, as follows-
(2) With multi-laminar type insulation under vacuum;