685S Liquid Level Indicator

The Model 685S is a liquid head pressure type level control. It continuously indicates the liquid level in an atmospheric (vented) vessel, in feet and inches, and has an adjustable switch which completes an electrical circuit to a solenoid, alarm, or other device when the level rises to the top predetermined point, and breaks the circuit when the level falls to the bottom predetermined point (or the reverse). Also, the scale of the Model 685S is available calibrated for horizontal cylindrical vessels or in pounds, gallons, barrel, etc. An elastomer diaphragm is the sensing element of the Model 685S, and also separates the liquid in the vessel from the mechanical working parts of the unit.

Features:

• Simple Adjustments - One high adjust dial for top level set point and on low adjust dial for bottom level set point. One Zero Adjust Knob and one Specific Gravity (span) Adjust Knob. Can be factory adjusted at a nominal cost, or field adjusted in less than 15 minutes without having to change the liquid level in the vessel.
• Easy To Read - Scale reads the same as a hand tank gauge making it unnecessary to convert PSI of head pressure into feet and inches of water to get correct reading.
• Corrosion Resistant - 56% of all parts, including all springs and wearing parts, are stainless steel. A total of 87% are Teflon, stainless steel, or aluminum.
• Long Life - All bearings are Teflon, delrin, or moly disulphide baked on dry-film lubricated stainless steel. Very lightly loaded in operation, main bearings are at least 1/4” diameter or more for long life and rugged service.
• Lower Prices - Cost, as to materials of construction, is less than comparable units in use today.
• Variety Of Switch Outputs - Available with SPST, SPDT, DPDT or multiple switch outputs.
• Pulsation Dampening - A snubber, or pulsation dampener, is available to reduce line surges if the unit is installed on a pump suction line.

Specifications:

• Vessel Inlet connection: 2” NPT; 2”-150# ASR R.F. FLANGE or 2” GROOVED, Cad Plated Ductile
• Diaphragm: Buna-N Standard
• Housing: cast aluminum
• Scale (Vessel Height): 3 feet thru 60 feet
• Operating Pressure: 0 to 4 ounces pressure (Atmospheric)
• Operating Temperature: -20deg F to +225deg F Standard
• Switch Contacts: SPDT Microswitch standard
• Switch Repeatability: + or -1% Full Scale of set points
• Electrical Connection: 1/2” Female Pipe thread. 3/4” Female Pipe thread optional
• Suitable for use in Class I, Division I, Group C and D, Class II, Division I, Groups E, F, G Hazardous locations
• Accuracy: Standard + or -2%; Options such as Teflon Diaphragm, 30 ft. or greater tank height, additional switches, transmitters, oil pneumatic output etc., reduce accuracy.