Application Data Sheet

Kayden Instruments

Pump Mechanical Seal Leak Detection


Pump Mechanical Seal Leak Detection


Kayden CLASSIC 812 Series Flanged Thermal Dispersion Flow, Level, Interface & Temperature Switch & Transmitter

Flow and liquid level detection in drain line systems.

Pumps require a form of mechanical seal, these seals will eventually break down and leak. Determining the point of failure is achieved by routine monitoring of the seal. Seal leak can be tolerated by directing the fluid into a recovery system by use of a drain line that directs the fluid into a storage container.

How is it determined when the leak is occurring and to what degree? The Kayden CLASSIC 800 Series Flow, Level, Interface and Temperature Switch/Transmitter will help you determine whether or not to shut down the pump or send out a maintenance crew to service the mechanical seal.

A common "Pipeline Leak Detection" setup for No Flow Condition, Pump Protection:

  • Staff can monitor the storage container and recover the leaked fluid, however, the storage container will quickly be overwhelmed if the seal fails and floods the recovery system.
  • Monitor inside the drain to detect if there is a fluid present and if so inform the relevant party.
  • Monitor the liquid level in the drain pipe while monitoring the flow rate. It is now possible to choose both an alarm point and a shut-down point using the Kayden CLASSIC 800 Series Switch/Transmitter.
Kayden CLASSIC 812
Kayden CLASSIC 812
Customer Specified T
Customer Specified T
Tee Drawing Solo CLASSIC 812 with Customer Specified T
CLASSIC 812 with
Customer Specified T
812 Tee Drawing
812 Front and Side

CLASSIC 812 Flanged

Flow, Level, Interface & Temperature Switch & Transmitter
Flow, Level, Interface & Temperature Switch & Transmitter
  • Flanged Process Connections - 316/316L Stainless Steel sensor standard
  • Exotic Alloys, Custom 'U' Lengths and Remote Mounted Electronics Available
  • Digital Microprocessor Technology - Settings configurable by user for Flow, Level, Interface & Temperature Sensing
  • No Jumpers - All Configurable Options are stored in Non-Volatile Memory
  • FM Explosion-proof Class I, Div. 1, Groups B, C & D
  • CSA/ANSI UL Flameproof Class I, Div. 1, Groups B, C & D
  • 316/316L Stainless Steel & Exotic Alloy versions designed to ASME Section VIII Div. 1 2007 Latest Addenda and/or to be inserted in system complying with ASME/ANSI B31.3-2006 +2007 Addenda. Canadian Registration Number (CRN): 0F09437.2

The Kayden CLASSIC 800 Series Electronics Module is designed for quick and easy setup.

  • Relay 1 & 2
  • Set Point 1 & 2
  • Fault Alarm
  • Run Mode
  • Start-up Bypass Timer (for pump control)
  • LED Bar Graph for Flow Rate, Level or Interface Indication
  • Universal Power 12-24 VDC & 115-230 VAC standard
  • Two SPDT Relays - independently adjustable
  • 4-20 mA Analog Output
  • "Smart Heater" function for power economy and increased heater life
  • Start-up Bypass Timer (for pump control)
  • Adjustable Sensitivity
  • Zero & Span Adjustment
  • Modbus Addressable
  • Easy setup; no jumpers or trim pots
  • Continuous Self-test Diagnostics with Fault Indicator
  • Temperature Compensation
Applications - Process Tank

CLASSIC 812 Specifications

  • Flow, Level, Interface & Temperature
  • Flanged
  • Custom Lengths:
    Available in 1/2" or 1 cm increments Min. 1.2"- Max. 120" (3.0 - 305 cm)
  • 316/316L Stainless Steel standard
  • Titanium Gr. 2, Hastelloy® C-276, Monel® 400, Inconel® 600, Alloy 20, Nickel 200
  • Copper-free Aluminum (does not exceed 0.4% copper)
  • Powder Coated Polyester TGIC (polyestertriglycidyl isocyanurate)
  • NEMA 4X / Type 4 / IP55
  • 1" FNPT Conduit Connection
  • Buna O-ring on Cover
  • Sensors:
    -45°C to +200°C (-50°F to +392°F)
  • Electronics:
    -55°C to +65°C (-67°F to +149°F)
    Note: For temperatures above +65°C (+149°F) electronics must be remotely mounted.
  • Storage:
    -55°C to +75°C (-67°F to +167°F)
  • Maximum Working Pressure: per flange rating
  • Water-based Liquids:
    0.01 to 3.0 ft./sec. (0.003 to 0.9 meters/sec.)
  • Hydrocarbon-based Liquids:
    0.01 to 5.0 ft./sec. (0.003 to 1.5 meters/sec.)
  • Gases:
    0.25 to 254 sfps (0.076 to 77 smps) Standard conditions: 21°C (70°F) at 14.7 psi (1 atm)
Classic 800 Display Panel
Display Panel

Display Panel Indicators:

Relay 1

On steady when Relay 1 is energized

Relay 2

On steady when Relay 2 is energized


Indicates a self-test error or fault condition

Set Point 1

On steady when viewing Set Point 1

Set Point 2

On steady when viewing Set Point 2

Run Mode

Flashing when switch is operating


Flashing when the Start-up Bypass Timer is active

Thermal Signal

Displays Thermal Signal

The Thermal Signal increases as:


The flow rate increases


The sensor is submerged


The sensor is submerged by the second liquid of greater thermal conductivity

  • Flow Service:
    ±1% set point velocity over operating range of ±28°C (±50°F)
  • Level Service:
    ±0.25 inches (±0.64 cm)
  • Approximately 0.5 to 30 seconds
  • Maximum recommended cable length - 200 feet (60 m)
  • Cable type - 24 AWG minimum - twisted pairs
  • Field adjustable to optimize performance
  • Universal Power standard 12-24 VDC and 115-230 VAC, 50-60 Hz
  • Consumption: Maximum: 4.8 watts (fully configured)
  • 4-20 mA current loop
  • Two (2) SPDT sealed relay contacts rated @ 5 amps resistive 230 VAC or 30 VDC Max.; individually adjustable
  • Adjustable for 0 to 100 seconds
  • Modbus via RS-485
  • Display Panel Lock-Out
  • Set Points configuration1
  • Relay Actuation Delay Timer
    • Independently configurable for both On and Off, increasing or decreasing
    • Adjustable from 0 - 5,000 seconds
  • Start-up Bypass Timer1
    • Adjustable from 0 - 100 seconds
  • Relay Mode Configuration1
    • Energized above or below set point
  • Relay Temperature Mode Configuration
  • Heater Power setting1
  • Zero and Span settings1
  • Analog (4-20 mA) output configuration1
  • View and Print Graphing (Trend) function
  • Configuring settings; write to device, save to file and print
  • Fault Event Log
1 Also configurable from Display Panel
  • Primary watchdog circuit monitors microprocessor parameter anomalies
  • Secondary watchdog circuit monitors microprocessor health
  • Heater monitored for out-of-range conditions
  • Fault Mode de-energizes relay(s) and halts power to the heater
    Class I, Div. 1, Groups B, C and D; Ex d IIB + H2; AEx d IIB+H2 (Class I, Zone 1, Group IIB + H2,) T3; Enclosure Type 4 / IP55
    CSA Logo
  • Single Seal Approval
    Per ANSI/ISA 12.27.01-2003
  • CRN
    Canadian Registration Number
    CSN Logo
  • FM
    Class I, Div. 1, Groups B, C and D; Class I, Zone 1, AEx d IIB+H2 T2D (Ta=75°C); T3 (Ta=65°C); Enclosure Type 4 / IP55
    FM Approved
  • 812 Flanged: 1-1/2” 300#, 7” U length - 16 lbs (7.25 kg)
  • Carton Size - 15” x 8” x 8” (38 cm x 20 cm x 20 cm)
  • One (1) Year from shipment date from factory (see Terms & Conditions on for details)

Applicable CLASSIC 800 Models

Classic 810
Classic 810
Classic 812
Classic 812
Classic 814
Classic 814
Classic 816
Classic 816
Classic 828
Classic 828
Classic 830
Classic 830
Classic 832
Classic 832

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