[F1 The CoverE+W+S
Textual Amendments
F1Sch. 2 repealed (10.9.1992) by S.I. 1992/1811, reg. 12(2), Sch. 3 Pt. I (by reg. 12(1) it is provided that this repeal shall have effect in relation to the value of the flash point of petroleum-spirit and the methods for determining it).
The cup is provided with a close-fitting cover with a downward projecting rim barely reaching the flange of the cup. The downward projecting rim is made solid with the top or silver soldered or brazed in place. Upon the cover are mounted a thermometer socket, trunnions to support an oil-test lamp, a pair of guides in which a slide moves, and a white bead. The top of the cover is pierced by three rectangular holes symmetrically placed on a diameter, one in the centre and the other two as close as practicable to the inner sides of the cover-rim and opposite each other. These three holes are covered or uncovered by means of a slide moving in suitably disposed guides. The slide has two perforations, one corresponding in all particulars to the centre hole in the cover and the other to one of the holes at the side. The movement of the slide is restricted by suitable stops, and its length and the disposition of the holes are such, that at the outer extremity of the movement of the slide, the holes in the cover are simultaneously just completely opened and at the inner extremity of the movement of the slide they are completely closed.
The trunnions supporting the test lamp are fixed on the top of the guides and the lamp is mounted in the trunnions so that it is free to oscillate. The lamp is provided with a jet to contain a wick and is so arranged that when the slide is moved so as to uncover the holes, the oscillating lamp is caught by a pin fixed in the slide and tilted over the central hole in such a way that the lower edge of the cover bisects the circle formed by the bore of the jet when in the lowest position. The flame then occupies a central position within the hole in both directions.
A suitably mounted gas-jet may be substituted for the lamp.
The thermometer socket is in the form of a split tube, mounted on a diameter at right angles to the diameter through the centres of the holes, and fitted at such an angle as to bring the bulb of the thermometer, when in place, vertically below the centre of the cover and at the correct distance from it.
A white bead, the dimensions of which represent the size of test flame to be used, is mounted in a visible position on the cover.
Materials:—all parts excepting bead:—brass or gunmetal. bead:—ivory or other suitable material.
| ——— | Dimension | Tolerance |
|---|---|---|
| Cover, thickness | 0·05in. | ±0·015in. |
| ,, central hole, length (in direction of slide). | 0·05in. | ±0·005in. |
| ,, width | 0·4in. | ±0·005in. |
| ,, peripheral holes length (in direction of slide) | 0·2in. | ±0·005in. |
| width | 0·3in. | ±0·005in. |
| Slide, thickness | 20 I.W.G. | |
| ,, width of upper surface | 0·5in. | ±0·01in. (excess only). |
| Lamp. Overall length of jet | Approx. 0·6in. | To suit the requirements for the position of jet when tilted. |
| ,, Bore of jet at end | 0·0625in. | ±0·005in. |
| Bead. Diameter | 0·15in. | ±0·01in. |
| Thermometer Socket: | ||
| Internal diameter | 0·6in. | ±0·01in. |
| Length of short side measured from under surface of cover. | Approx. 0·5in. | |
| Length of long side measured from under surface of cover. | Approx. 0·75in. | |
| Distance of centre of socket from centre of cover measured on the underside | approx. 0·7in. | |
| These dimensions are subject to the correct placing of the thermometer when in position. | ||
| Vertical depth of lowest part of thermometer below centre of under-side of cover. | 1·5in. | ±0·1in.] |