gases. The volume of the contained helium bears the same proportion to the volume of the mixture that the purity of the helium bears to 100 percent.
(g) "Unit of helium" means 1,000 cubic feet of contained helium measured at, or reduced to, a pressure of 14.7 pounds per square inch absolute and a temperature of 70° Fahrenheit.
(h) "Standard-type cylinder" means a cylinder of approximately 1.5 cubic feet internal volume, designed for a filling pressure of 1,800 pounds per square inch gauge or more, which will stand vertically without external support with the center of the valve outlet not less than 50½ inches nor more than 58½ inches above the floor, equipped with a standard-type cylinder valve and valve-protective cap, or a similar cylinder acceptable to the Bureau as a standard type,
(i) "Standard-type cylinder valve" means a valve acceptable to the Bureau in all respects, having an outlet con- forming to following specifications: U. 8. standard form left-hand threads, 14 threads per inch, threaded portion ⅝ inch in length; major diameter not more than 0.830 nor less than 0.824 inch; pitch diameter not more than 0.784 nor less than 0.780 inch; outlet opening drilled to have a diameter of not more than 0.504 nor less than 0.500 inch and a depth of not less than ⅜ nor more than ½ inch; inside edge of opening rounded out to a radius of 1/16 inch to permit insertion of a male connection tapered at an angle of 0 degrees: Provided, That at the Bureat's option valves with outlets conforming to other specifications may be accepted as alternative standards. Each cylinder valve shall be equipped with an outlet-port cap.
(j) "Helium tank car" means a railroad car of the type used by the Army and Navy for transporting helium, on which cylinders designed to hold helium under high pressure are mounted permanently.
(k) "Helium semi-trailer" means & vehicle without motive power of & type used by the Army or Navy for transportation of helium by road, on which cylinders designed to hold helium under high pressure are mounted permanently.
(l) "Free time" means the following periods or parts thereof included within the time between the placement of a helium tank car on the purchaser's track or in other specified discharge position, and removal therefrom by the carrier for return shipment:
(1) The first Sunday following placement; the first legal national, state, or municipal whole-day holiday following placement; and the Monday following any such holiday that falls on Sunday.
(2) The period between placement and the end of the first 48-hour period (exelusive of any period falling within a Sunday, legal national, state, or municipal whole-day holiday, or Monday following such a holiday that falls on Sunday) after the first 7:00 a. m. subsequent to the placement.
(3) Any period during which the car is ready for removal and the carrier has been notified that it is ready for removal, and the time of removal.
(4) Any period during which the car cannot be unloaded or moved because of unserviceable conditions not caused by any fault of the purchaser.
§ 1.2 Purchase price of helium. (a) The purchase price per unit of helium, at a helium plant to be selected by the helium of normal purity of 99.5 percent or more delivered at pressures not exceeding the normal plant pressure of approximately 2,500 pounds per square inch gage, shall be $19.00.
(b) Minimum charge. Notwithstanding the provisions of paragraph (a) of this section, the minimum charge for the helium delivered under any one contract shall be $380.00.
[19 F. R. 788, Feb. 11, 1954]
§ 1.3 Service Charges. The following charges for services and for use of equipment supplied by the Bureau shall be paid by the purchaser, in addition to the purchase price:
(a) For filling standard-type cylinders. $2 per unit of helium delivered.
(b) For work performed on standard-type cylinders supplied by the purchaser.
(1) For hydrostatic testing and stenciling test date: $1.30 per cylinder.
(2) Sealing cylinder valves: $0.05 per cylinder.
(3) Stenciling serial numbers: $0.10 per letter or figure.
(4) Installing valves supplied by purchaser in cylinders received without valves: $0.25 per cylinder.
