Lock oll set screws in seats ond guides of three points with
center punch Apply white leod in oil to moting surface of
the bonnet and body before bolting ports together which
ore to be left permanently assembled

Fit pockings 21. 85, 86, 87, and in shop so that they are just
snug and not fightly compressed in stuffing bos

See Note A on Dag 459-0.490 for instructions on spliced joint for gaskets, port 23

YELLOWTAIL DAM
RIVER OUTLETS

84 RING-FOLLOWER GATE ASSEMBLY-SECTIONS

(b) Design.-The hollow-jet valves were designed to regulate the discharge from the 84-inch outlet pipes under any head up to 465 feet. The plunger capacity was based on the sliding friction of the plunger and packings plus the hydrostatic force from full reservoir head acting on the upstream face of the needle. V-type packings are provided to minimize leakage past the plunger. Stainless steel seats are provided on both the upstream body and the needle. Stainless steel cladding was used on the exterior surfaces of the plunger to prevent corrosion.

The maximum stresses used for design were based, in general, on the following criteria:

(1) Tensile.-The allowable design stresses in tension used for the following materials were the

lower value of the percentages of the yield and ultimate strength of the material:

Material

Type

Percent of yield point

Percent of ultimate strength

Figure 89.84-inch hollow-jet valve assembly for the river outlets.

recommendations of the ASME Boiler and Pressure Vessel Code-Unfired Pressure Vessels-Section VIII.

70. CONTROLS FOR 84-INCH RINGFOLLOWER GATES AND 84-INCH HOLLOW-JET VALVES. The controls are required to operate the ring-follower gates and the hollow-jet valves. The controls were manufactured by Kendo, Inc., under Invitation No. (D)76,552-A.

(a) Description.-The control cabinet is of steel construction and is located in the outlet structure between the ring-follower gates, as shown on figure 92. The cabinet encloses the control system for both the ring-follower gates and the hollow-jet valves, as shown on figure 93. The equipment in the cabinet consists of two oil pumps, each having a capacity of approximately 11 gallons per minute when pumping oil at 2,000 pounds per square inch; two 15-hp., 440-volt, 3-phase, 60-hertz electric motors; connecting piping; and hydraulic and electric controls. A dial-type position indicator for each hollow-jet valve is located on the cabinet control panel to show the percentage of valve opening. The indicators are driven by roller chains and cables which lead through pipes from the hollow-jet valves to the cabinet. Two interconnected 326-gallon oil tanks are located on top of the cabinet to keep the minimum oil level above the gate cylinders. An oil level gage is located on one tank. The estimated weight of the control system is 8,750 pounds.

(b) Design.-The control system was designed for a maximum operating pressure of 2,000 pounds per square inch, using a light hydraulic oil (150 seconds Saybolt at 100° F.). A pressure switch limits the system pressure to 1,800 pounds per square inch for oepning or closing the ring-follower gates. The oil pressure for opening the hollow-jet valves is limited to 500 pounds per square inch by a relief valve, and the pressure for closing is limited to 900 pounds per square inch by a pressure switch. Only one ring-follower gate or one hollow-jet valve should be operated at a time. For normal operation both pumps operate; however, if one pump or motor becomes inoperable, a ringfollower gate or a hollow-jet valve can be operated at half speed with one pump. Approximately 8 minutes are required to close and about 6 minutes are required to open a ring-follower gate. Approximately 10 minutes are required to close a hollow-jet valve. The opening time is variable and should be set to open in 6 to 10 minutes. Remote controls are not provided.