. Electric railway journal . Indicating Flow Meter size pipe, under any commercial conditions of pressure andtemperature. The acting principle of the flow meter is a modification ofthat of the Pitot tube. A brass nozzle plug, screwed into thepipe at the point where the flow is to be measured, carries twosets of openings: a leading set, facing the direction of flow andextending diametrically across the pipe, and a trailing set, con-sisting of two openings at 90 deg. and one at 180 deg. to thedirection of flow. The impingement of the steam against the To Nozz/e P/Og. Automatic Pressure Correctio
. Electric railway journal . Indicating Flow Meter size pipe, under any commercial conditions of pressure andtemperature. The acting principle of the flow meter is a modification ofthat of the Pitot tube. A brass nozzle plug, screwed into thepipe at the point where the flow is to be measured, carries twosets of openings: a leading set, facing the direction of flow andextending diametrically across the pipe, and a trailing set, con-sisting of two openings at 90 deg. and one at 180 deg. to thedirection of flow. The impingement of the steam against the To Nozz/e P/Og. Automatic Pressure Correction Device leading openings sets up in them a pressure equal to the staticpressure plus the pressure due to the velocity head, while thetrailing set is acted on by the static pressure less that due tothe velocity. The difference in these values is a measure ofthe velocity, and for constant temperature and pressure givesthe rate of flow. The pressures existing in the two sets of openings are communicated through separate tubes to the outerend of the plug and from there by %-in. iron pipes to themeter. The recording steam-flow meter, Type R, Form D, is a curve-drawing instrument, calibrated to record the total rate ofsteam flow in pounds per hour. In this meter there are twocylindrical cups filled with mercury to about half their heightand joined at the bottom by a hollow U tube, which issupported on, and free to move as a balance about, a set ofknife edges. The two pressures obtained by the nozzle plugare communicated to the cups by flexible steel tubing, wher
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyorkmcgrawhillp
