ASME MFC-8M pdf free download

ASME MFC-8M-2001 pdf free download.FLUID FLOW IN CLOSED CONDUITS: CONNECTIONS FOR PRESSURE SIGNAL TRANSMISSIONS BETWEEN PRIMARY AND SECONDARY DEVICES.
This Standard provides guidance in the design of the pressure signal connections between a flowmeter primary device and the secondary device where they are physically separate and connected by gauge lines or impulse piping. The primary device or flow element creates a pressure difference or head at the pressure taps, which is related to the flow rate. The secondary device may display and may convert and transmit the flow signal to another location.
2 SCOPE This Standard describes the practices and means which allow the pressures at a head type primary device to be conveyed to the secondary device in a flow measurement system without introducing unnecessary measurement uncertainties.
2.1 Field Of Application This Standard is concermed only with the transmission of the pressure difference developed by a head type primary flow element. It does not address the characteris- tics of the primary or secondary devices, or transducers or other instruments. Electrical transmission techniques are not considered.
2.2 References and Related Documents The following is a list of publications referenced in this Standard. Unless otherwise specified, the referenced standard shall be the most recent issue at the time of order placement. ASME Fluid Meters, Their Theory and Application, Sixth Edition, 1971 ASME MFC-3M, Measurement of Fluid Flow in Pipes Using Orifice, Nozzle, and Venturi (not an American National Standard)
ASME PTC 19.2, Instruments and Apparatus: Part 2一 Pressure Measurement Publisher: The American Society of Mechanical Engi- neers (ASME), Three Park Avenue, New York, NY 10016; Order Department: 22 Law Drive, Box 2300, Farfield, NJ 07007-2300
3 GENERAL
3.1 Containment Safe containment of the fiuid requires conformance to the applicable standards and codes, and requires the selection of the proper materials of construction; the fabrication methods and practices; fttings; and any required gaskets or sealing materials.
3.2 Codes The pipe or tubing installed between the primary and secondary devices must comply with applicable requirements such as national, local and owner codes, standards, and guidelines. The process piping specifica- tion determines the specifications for the block or the valve closest to the primary element. The specifications for the piping between this valve and the secondary device, and any valves in this piping, may differ. The small size, limited fow, and often the more limited temperatures involved, justifies these differences (see Fig. 1).
3.3 Specification Break The break (change) in piping specifications between process and the secondary or instrument side is normally ut the secondary end connection of the process valve (see Fig. 1). If the process piping specification requires flanged connection, then the process end of this valve is flanged and the mating flange on the secondary side is an instrument connection or may have another approved ftting. 3.4 Pressure Test An approved hydrostatic pressure test may be required for piping systems to prove the integrity of the pressure containing parts of the piping system.
3.5 Inspection A visual inspection of each installation is recom- mended for adherence to safety and measurement re- quirements before putting each flowmeter into operation (see MFC-3M). Install primary per manufacturer instruc- tions.
3.6 Rod Out Some installations will require provision for rodding out of the process connections. This is the use of a rod or other physical device to remove materials blocking the free flow of fluid into the impulse lines. Observe the applicable safety precautions. 3.7 Valve Orientation Globe style block valves may create a pocket of gas or liquid if they are installed with the stem in the vertical orientation. This pocket may result in a pressure difference and an error in the indicated measurement. Installation with the stem at an angle of 90 deg from the vertical normally solves this problem. Ball valves and gate valves do not have this problem.ASME MFC-8M pdf download.