Pneumatic Transmitters Model 25 Liquid-Level Controller Introduction Features & Benefits Flexible shaft design has no process-wetted pivots or links to foul Actuation motion of 1/32" provides precise measurement Wide variety of flange sizes and materials simplify mounting Standard process wetted parts are 316SS, improving corrosion resistance Description The Model 25 Liquid-Level Controller consists of a float mounted on a short float arm connected to the free-end of a packless flexible shaft. The fixed-end of this flexible shaft is attached to a standard flange. The tubular shaft has a formed center section (similar to a bourdon tube in cross section), which permits only vertical float motion. The rigid float arm extension within the shaft transmits the float motion to the air pilot for operation of a diaphragm-type motor control valve. The Model 25 Liquid-Level Controller operates on the change in buoyant force of the float-not the motion of the float riding on a changing liquid level. A buoyancy change of less than six ounces will provide full actuation of the pilot valve or contact switch. The Model 25 also has limit stops to maintain the shafts within the elastic limit. A wide range of specific gravities and level-change requirements can be accommodated via elliptical, cylindrical, and other special floats. These units can be mounted on the direct side of a vessel flange or externally mounted in a float chamber. Standard piping connections on the float chamber are 1" NPT. Specifications Pressure Full vacuum to flange rating Temperature Minimum: 32°F (0°C) Maximum: 300°F (150°C) Specific Gravity Consult Float Size Table for minimum specific gravity Float Size Table Material Ball Float Size 316 SST Hastelloy C X X X X 3-1/2" Dia. 4" Dia. 5" Dia. Suitable for minimum specific gravity of: 0.5 0.35 0.25 Options 8 Elastomer Coatings Coating of all wetted parts to increase corrosion resistance Available coatings: Neoprene, TFE/PTFE, Kynar 8.16 Pneumatic Transmitters Model 25 Liquid-Level Controller Ordering data Float Chamber1,2 Part Numbers Liquid-Level Controller - Pneumatic Liquid-Level Controller - Electric Flange Size Float Chambers Steel Casting 4" Type 316 SS Casting 6" Welded Steel Pressure Rating Part No. Part No. Part No. 150# 300# 8537-1 8537-51 8537-201 8537-224 8537-46 8537-47 Flange or Connection Material • Steel • Stainless Steel Flange Size and Rating • 4" - 150# • 4" - 300# • 6" - 150# • 6" - 300# • 1-1/2" Threaded Connection Options • Float Chamber • Reverse Acting (Pneumatic Only) • Tee Assembly (for Top Mounting) Mounting Dimensions — For Tees and Chambers Standard A FlangeFlange Bolt Class Size Dia. Circle Steel 150 Steel 300 Steel 400 Steel 600 7-1/2 9-1/2 7-7/8 10-5/8 7-7/8 10-5/8 8-1/2 11-1/2 4 6 4 6 4 6 4 6 9 11 10 12-1/2 10 12-1/2 10-3/4 14 B Order No. Model Number ▲ ▲ ▲ C S 415 430 615 630 15 C R T Bolt C D E3 H J K Flange Tee: Face Chamber: Chamber: Chamber: Chamber: No. Size Thick- Center to Center Length Body ness to Face Ball to Face to Face Diameter 8 8 8 12 8 12 8 12 5/8 3/4 3/4 3/4 7/8 7/8 7/8 1 1-5/16 1 1-1/4 1-7/16 1-3/8 1-5/8 1-1/2 1-7/8 6-1/2 8 7 8-1/2 8 9-3/4 8-1/2 11 4-3/4 4-11/16 4-7/16 4-1/4 4-3/4 4-3/4 4-3/4 4-3/4 6-1/2 6-1/2 6-1/2 6-1/2 11-3/8 12-5/8 11-3/8 12-5/8 2527■■■ 5-3/4 6-5/8 5-3/4 6-5/8 L Height at Conn. 8-1/2 9-1/2 8-1/2 9-1/2 Standard 4"-150# and 4"-300# cast-steel chambers have 1-1/2" I.P.S. connections. Other chambers can be furnished with 1-1/2" or 2" I.P.S. connections. Data will be furnished on request. 1) Chambers are constructed with 1-1/2" female NPT connections, top and bottom. 2) Chambers not listed above are considered special and will be priced on application. 3) F = E + diameter of ball. 8.17 8 Pneumatic Transmitters Model 25 Liquid-Level Controller Technical data Installation Drawings Vertical Float Displacer Chamber In order to provide for vertical motion of the float, the mounting nozzle should be installed with its flange face vertical and the bolt holes straddling the center line (as shown below). As shown below, a displacer chamber is recommended if the liquid level can be disturbed by surges. Shut-off valves are also advisable to allow the controller to be removed without shut-down. Provisions can be made to periodically flush-out the displacer chamber by connecting a purge line. Controllers can be furnished for installation in a tee on top of the tank. If the vertical extension is greater than 24", or if the liquid level can be disturbed by surges, a suitable baffle or cage that does not touch the float should be installed. 8 8.18