ANSI B109.3-2000 pdf download.ROTARY-TYPE GAS DISPLACEMENT METERS
2.12.2.1 Each reading circle shall be divided into 10 equal parts with division marks numbered from “O” to “9.” The “O” division mark shall be located at the top of the circle. The reading circle shall be a minimum of 0.6 inch (15 mm) in diameter.
2.12.2.2 The index gearing shall provide for adjacent reading hands to rotate in opposite relative directions in a 1040-1 ratio.
2.12.2.3 The fastest moving reading hand shall be located to the right of the index when viewed from the front of the index.
2.12.2.4 The fastest moving reading hand shall rotate in a clockwise direction and have a value per revolution of 1,OO0 CU. fi. (28.3 m3) when installed on a 10 CU. fi. (0.28 m3) per revolution meter, 1,OOO CU. R. (28.3 m3) when installed on 8 100 CU. ft. (2.8 m3) per revolution meter, and 10,OOO CU. ft. (283.2 m3) when installed on a 1,OOO CU. ft. (28.3 m3) per revolution meter.
2.12.2.5 Each reading circle shall be appropriately marked to indicate the number of volume units measured per complete revolution of the reading hand and shall be provided with an arrow indicating the direction of rotation of the reading hand.
2.12.2.6 On non-reading circles with a “proving hand” or “test hands,” the volume per revolution shall be clearly indicated. The circle shall have 10 equally spaced divisions, and a directional arrow shall be provided to show the direction of rotation. No numbers shall appear on the subdivisions.
2.123 Direct Reading Indexes (Digitai or Counter Type).
2.12.3.1 nie digits of the counter shall be arranged to appear in a horizontal straight line that can be viewed through a cutout in the index face or counter mask.
2.12.3.2 A permanent multiplier or zeroes shall appear on the index face.
2.12.3.3 An appropriate test hand or unit shall be provided for proving. It shall be suitable for scanning by photoelechic or other mechanical or electronic means.
2.13 CORROSION AND CHEMICAL RESISTANCE OF INTERNAL PARTS
Internal parts and surfaces of the meter shall be resistant to corrosion or chemical attack that would adversely affect the operation of the meter when used to measure pipeline quaiity gas.
2.14 CORROSION AND CHEMICAL RESISTANCE OF EXTERNAL PARTS
The meter case and external parts shall be made of or protected by materials that are resistant to attack by the weathex (sunlight, humidity and temperature changes) and common meter cleaning agents over the expected life of the meter. The meter case and exterior parts shail be capable of meeting or exceeding the requirements of the following tests.
2.14.1 Accelerated Weathering Test.
Representative samples of the meter case and other external parts exposed to the atmosphere, with no special protection other than the material used in manufacture, shall be exposed for 2,000 hours to the following weathering tests in accordance. with the “‘Recommended Practice for ûperating Light and Water Exposun Apparatus (Carbon Arc Type) for Testing Paint, Varnish, Lacquer and Related Products,” ASTM D822.
2.14.2 Salt Spray Test.
Samples as in 2.14.1 shall be mounted in a salt spray chamber in the normal operating position and subjected to a 1,000-hour salt spray test in accordance with the ASTM Method BI 17-1973, “Sait Spray (Fog) Testing.” As a result of this test, there shall be no appreciable signs of blistering, corrosion or deterioration of the surface. The samples shall show no sips of progressive corrosion or electrolytic action after being stored, without washing or cleaning, in a dry indoor location for a period of six months.ANSI B109.3-2000 pdf download
