AS 2360.1.4-1993

Section one - General0 Introduction1 Scope2 Symbols and definitions3 Effect of errors on flowrate calculationsSection two - Effects of deviations in construction4 Orifice plate edge sharpness5 Thickness of orifice edge6 Flatness of upstream face7 Position of pressure tappings8 Condition of pressure tappingsSection three - Effects of pipeline near the device9 Pipe diameter10 Steps and taper sections11 Diameter of carrier ring12 Undersize joint rings13 Protruding welds14 EccentricitySection four - Effects of pipe layout15 General16 Discharge coefficient compensation17 Pressure tappings18 Devices for improving flow conditionsSection five - Operational deviations19 General20 Buckling of an orifice plate21 Deposition on the upstream face of an orifice plate22 Deposition in the meter tube23 Deposition and increase of surface roughness in venturi tubes24 Orifice plate edge squarenessSection six - Pipe roughness25 General26 Upstream pipe27 Downstream pipe28 Reduction of roughness effects29 MaintenanceAppendix A Bibliography

Provides guidance to assist in estimating the flow rate when using pressure differential devices constructed or operated outside the scope of Part 1.1. The information given permits users who may not be able to comply fully with the requirements to assess, however roughly, the magnitude and direction of the resulting errors. It is identical with and has been reproduced from BS 1042:Section 1.5:1987.

This Section of BS 1042 provides guidance to assist in estimating the flowrate when using pressure differential devices constructed or operated outside the scope of BS 1042 : Section 1.1.It should not be implied that additional tolerances or corrections can necessarily compensate for the effects of deviating from the standard. The information is given, in the first place, to indicate the degree of care necessary in the manufacture, installation and maintenance of pressure difference devices by describing some of the effects of non-compliance with the requirements; and in the second place, to permit those users who may not be able to comply fully with the requirements to assess, however roughly, the magnitude and direction of the resulting errors.Each variation dealt with is treated as though it were the only one present. but where more than one is known to exist, there will be interactions causing increases or decreases of error, largely unpredictable. This list of variations is by no means complete and relates largely to examples with orifice plates. There are, no doubt, many similar examples of installations not complying with BS 1042 : Section 1.1 for which no comparable data has been published. Such additional information from users, manufacturers and any others may be taken into account in future revisions of this Section of BS 1042.NOTE. The titles of the publications referred to in this standard are listed on the inside back cover.

First published as AS 2360.1.4-1993.