tom of each pot was connected with copper tubing to a 30-in differential manometer which used mercury as the meterAir-water two-phase flow was utd-(1 ) in 1955 published a correlation ing element. The portion of the pots below ized as early as 1797 in an air-lift for pressure drop in horizontal turbu-the taps and the copper tubing were filled pump invented by a German, Carl lent flow. Experimental data were ob-with the test liquid as a seal fluid on the Loscher. Vertical two-phase flow was tained in l-%-in. and 3-in. pipes at mercury. The diameter of the surge pots again used in 1927 in the Seminole, pressures up to 100 lb./sq. in. abs. was selected so that the cross-sectional Oldahoma, oil fields to produce oil by The correlation shows agreement within area of the pots was about 200 times the gas lift. Cromer (2) in 1936 visually 20% for these data and the data used crcss-sectiond area of the nmmw~er-A observed the upward flow of mixtures by Lockhart and Martinelli for their change in manometer level thus reflected a negligible change in level in the surge of air and water in a vertical pipe. correlation. Four flow regimes were reported, but Vertical steam-water flow at high pot. One quick shutoff valve was installed in practice the transition between pressure has been of interest for nu-below the bottom pressure tap and a setregimes is indistinct and it is some-Clear reactors. Egen, Dingee, and above the top pressure tap. These times difficult to determine the regime Chastain ( 4 ) reported holdup data for l-in. valves were closed by air pressure for a given condition. Schurig (I?'), steam-water at 2,000 lb./sq. in. abs. from two solenoid valves. Each solenoid Kr:gel ( l o ) , Dukler ( 3 ) , McElwee in a channel 1 in. by 0.103 in. cross and shutoff valve was connected by iden-(14), Galegar, Stovall, and Hunting-section. Studies of pressure drop and tical piping, and the solenoids were operton ( 5 ) , and Govier, Radford, and heat transfer during boiling have been ated from a single electrical switch to obDunn (6) have obtained data for the reported by many investigators (9, 12, tain simultaneous shutoff of the valves.A pressure gauge was installed in the air-water system in vertical upward 13, 19, 20). flow. Yagi and co-workers (21, 22) obThe purpose of the research de-test section at the Of the bottom tained data for the air-water and air-scribed here was to obtain data for a pressure tap. A drain connection was provided above the bottom valve, and a vent oil systems over limited ranges of flow. variety of liquids over a wide range was installed below the top valve.Sehwarz (18) reported holdup data of flow rates and from this to obtain The desired liquid flow for a run was for the steam-water system at 20-to generalized correlations that would lnetered to the test section through a 80-atm. pressure. Isbin, Sher, and permit reliable prediction of holdup rotameter. After the manometer had Eddy (7) reported holdup data for and pressure drop in vertical upward reached a steady reading, the desired gas the steam-wa...