Type Y692 Gas Blanketing Regulator System Figure 1. Type Y692 Low-Pressure Gas Blanketing Regulator An Accu-Pressure™ Gas Blanketing Regulator System reduces a high-pressure gas, such as Nitrogen, to maintain a protective environment above any liquid stored in a tank or vessel when the liquid is being pumped out. Also when the vessel is suddenly cooled, causing vapors inside the vessel to contract, the regulator system replaces the volume of contracting vapors with a volume of blanketing gas to prevent the internal vessel pressure from decreasing. In both cases, a slight positive vessel pressure prevents outside air, moisture and other contaminants from entering the vessel and the possible collapse of the vessel walls. The Type Y692 (Figure 1) is a direct-operated regulator used for accurate pressure control on very low-pressure blanketing systems. Downstream pressure is sensed through a pitot tube installed in the lower casing of the regulator for units with internal pressure registration or through a downstream control line for units with external pressure registration. • Ease of Inspection and Maintenance—The union nut connection between the body and actuator permits access to the disk and orifice by only removing the diaphragm casing assembly without removing the body from the line. • Accuracy of Control—Large diaphragm areas provide more precise control even at low-pressure settings and the pitot tube also creates a dynamic boost that helps provide greater capacity. • Speed of Response—The downstream pressure is sensed directly by the diaphragm through the pitot tube providing quick response. • Ease of Installation—The Type Y692 is easy to install in the pipeline because no additional Process Management

Available Configurations Direct-operated pressure reducing regulator with external or internal pressure registration with seven outlet (control) pressure ranges from 1-inch w.c. to 7 psig / 2 mbar to 0.48 bar. Available in Body Sizes and End Connection Styles'1' Maximum Outlet (Casing) Pressure'2' Maximum Operating Outlet (Control) Pressure to Avoid Internal Part Damage'2' 3 psig / 0.21 bar above outlet (control) pressure setting Flow Capacities Relief Sizing Coefficients Orifice Size Pressure Registration Internal (standard) or External Spring Case Connection Perfluoroelastomer (FFKM): EthylenePropylene...

Table 1. Control Pressure Ranges Table 2. Flow Rate Conversion'1' Table 3. Conversion Factors (for converting Nitrogen flow rates to other gas flow rates) Table 4. Gas Flow Required for Thermal Heating (Outbreathing) or Cooling (Inbreathing) per API 2000 (Interpolate for Intermediate size)

Bulletin 74.1:Y692 Type Y692 Type Y692 VENT VALVE BLOCK VALVE SUPPLY PRESSURE VENT VALVE VENT POINTED DOWNWARD BLOCK VALVE T GAS BLANKETING PRESSURE July 2007 Type Y692 INLET PRESSURE OUTLET PRESSURE ATMOSPHERIC PRESSURE LIQUID TYPE Y692 WITH INTERNAL REGISTRATION Type Y692 VENT VALVE BLOCK VALVE INLET PRESSURE CONTROL PRESSURE (OUTLET PRESSURE) SUPPLY PRESSURE ATMOSPHERIC PRESSURE VENT VALVE VENT POINTED DOWNWARD BLOCK VALVE GAS BLANKETING PRESSURE LIQUID TYPE Y692 WITH EXTERNAL REGISTRATION A6340 INLET PRESSURE CONTROL PRESSURE (OUTLET PRESSURE) ATMOSPHERIC PRESSURE INLET PRESSURE Figure OUTLET...

Bulletin 74.1:Y692 Principle of Operation Installation The Type Y692 Gas Blanketing Regulator reduces a high-pressure gas to maintain a positive low-pressure of blanket gas over a stored liquid when the liquid is being pumped out of the vessel (see Figure 2). Also when the vessel (or tank) is suddenly cooled, causing vapors to contract, the regulator replaces the volume of contracting vapors with a volume of blanketing gas to prevent the internal vessel pressure from decreasing. In both cases, a positive vessel pressure prevents outside air from entering the vessel and reduces the possibility...

Bulletin 74.1:Y692 API 2000 The American Petroleum Institute Standard 2000 (API 2000) sizing method accounts for liquid pump-out as well as contraction of tank vapors due to cooling. When using API methods: Qtotal = Qpump + Qthermal where, Qtotal = Required Flow Rate Qpump = equired Flow Rate to replace pumped out R liquid from Table 1 Qthermal = equired Flow Rate due to thermal cooling. R See Thermal Equations 1 to 4 below or Table 2. Thermal Equations For tanks up to 840,000 gallons / 3179 m3 capacity, use one of the following equations: Equation 1: Qthermal [SCFH Air] = Vtank x 0.0238 Equation...

Bulletin 74.1:Y692 Capacity Information Ordering Information Table 5 gives the typical regulating capacities at selected inlet pressures and outlet (control) pressure settings. Flows are in SCFH (60°F and 14.7 psia) of 0.97 specific gravity nitrogen. For gases of other specific gravities, multiply the given capacity of nitrogen by 0.985, and divide the given capacity by the square root of the appropriate specific gravity of the gas required. Then, if capacity is desired in normal cubic meters per hour at 0°C and 1.01325 bar, multiply SCFH by 0.0268. When ordering, specify: To determine wide-open...

Table 5. Blanketing Regulating Capacities in SCFH / Nnf/h of 0.97 Specific Gravity Nitrogen ORIFICE SIZE, INCHES / mm 1. Spring ranges based on regulator installation with the spring case pointed down. I I - Light shaded areas show where indicated droop would be exceeded regardless of capacity. I I - Dark shaded areas show where maximum operating inlet pressure for a given orifice size is exceeded.

Table 5. Blanketing Regulating Capacities in SCFH / Nnf/h of 0.97 Specific Gravity Nitrogen (continued) 1. Spring ranges based on regulator installation with the spring case pointed down. I I - Light shaded areas show where indicated droop would be exceeded regardless of capacity. I I - Dark shaded areas show where maximum operating inlet pressure for a given orifice size is exceeded.

Table 6. Orifice Sizes and Coefficients for Relief Valve Sizing CONTROL LINE A - CAST IRON FLANGES ARE 10-INCHES / 254 mm FACE-TO-FACE; STEEL, STAINLESS STEEL, AND HASTELLOY8 C FLANGES FLANGED DIMENSIONS