Series 123/125 Boiler Water Level Control

Heavy Duty, Cast Iron Chamber

The SERIES 123 & 125 Boiler Water Level Controls are designed for boiler applications, the 123 is primarily used for low water cut-off or feed-water control. Other applications include condensate tanks and deaerators. A special snap action switch mechanism eliminates frequent operation due to surging water level. A transparent cover provides convenient visible operation of the switch. Features a flanged chamber for easy clean out and replacement of float or switch mechanism without removing the unit from piping. The 125 offers the same long lasting service with a direct action mercury switch movement that provides a close deadband where needed.

Product Applications

  • Boiler Low Water Cut-Off
  • Boiler Feed-Water Control
  • Condensate Tanks
  • Deaerators

Models & Ordering

Build Your Custom Part. Use our Product Configurator

Model Description Usually Ships Price Order
123-153
Ships: Next Day
Price: $340.00
Water level control, cast iron chamber, SPDT mercury switch. Next Day $340.00 Order
123-2
Ships: Next Day
Price: $340.00
Water level control, cast iron chamber, SPST mercury switch, closes on increase. Next Day $340.00 Order
123-3
Ships: Next Day
Price: $340.00
Water level control, cast iron chamber, SPST mercury switch, opens on increase. Next Day $340.00 Order
123-7000-153
Ships: Next Day
Price: $340.00
Water level control, cast iron chamber, SPDT snap switch. Next Day $340.00 Order
123-804
Ships: 1-2 Weeks
Price: $453.00
Water level control, cast iron chamber, DPDT (2 SPDT) mercury switches. 1-2 Weeks $453.00 Order
125-4820
Ships: 1-2 Weeks
Price: $372.50
Water level control, cast iron chamber, SPST mercury switch, closes on decrease. 1-2 Weeks $372.50 Order
125-4821
Ships: 1-2 Weeks
Price: $372.50
Water level control, cast iron chamber, SPST mercury switch, opens on decrease. 1-2 Weeks $372.50 Order

Can't find what you need? Build Your Custom Part. Use our Product Configurator

Specifications

Service:
Compatible liquids. Cast iron is not for use with lethal or flammable substances either liquid or gaseous.
Wetted Materials:
Body: Cast iron. Float: 304 SS. Trim and packing gland: Brass. Packing: Carbon. Body gasket: Carbon.
Temperature Limit:
Ambient Temperature: 212°F (100°C); Process Temperature: 365°F (185°C).
Pressure Limit:
150 psig (10.34 bar).
Enclosure Rating:
General purpose. Optional weatherproof.
Switch Type:
SPDT snap switch or mercury switch. Optional DPDT or two stage.
Electrical Rating:
Snap switch: 15 A @ 120/240/480 VAC, 0.5 A @ 120 VDC resistive, 0.25 A @ 240 VDC resistive. Mercury switch: 4 A @ 120 VAC/DC, 2 A @ 240 VAC/DC.
Electrical Connections:
Screw terminal.
Conduit Connection:
7/8" (22.23 mm) hole for 1/2" (12.7 mm) conduit.
Process Connections:
1" female NPT.
Mounting Orientation:
Vertical.
Deadband:
Approximately 1-1/2" (38.1 mm).
Specific Gravity:
0.88 min.
Options:
Manual reset.
Weight:
20 lb (9.1 kg).
Agency Approvals:
CSA, UL. (Snap switch is not rated).

Features

  • Special snap action switch mechanism options eliminates frequent operation due to surging water level
  • Transparent cover provides convenient visible operation of the switch
  • Flanged chamber for easy clean out and replacement of float or switch mechanism without removing the unit from piping

Accessories

Model Number Description Usually Ships Price Order
121-116 Gland assembly (replacement part) 1-2 Weeks $113.00 Order
18-110L Lexan cover, gen encl (replacement part) 1-2 Weeks $33.25 Order
45-26SS SS float (replacement part) 1-2 Weeks $208.00 Order
121-11SS 2-3/4" SS float rod (replacement part) 1-2 Weeks $43.75 Order
121-14-1 Body gasket (replacement part) 1-2 Weeks $40.75 Order

Model Chart

 
EXAMPLE 123 2   123-2 Liquid Level Control with SPST mercury switch closing on level increase, minimum specific gravity 0.88, cast iron body, general purpose case, switch rated at 10 amp 120 VAC/DC, 5 amp 24 VAC/DC, pressure rating 150 psi (10 bar), maximum process temperature 365°F (185°C).
CONNECTION 123     Single Stage, Automatic Reset, Brass Trim, NEMA 1
123XLW     Replacement Float, Cap, and Switch Assembly Only, No chamber for 123
123WP     Single Stage, Automatic Reset, Brass Trim, NEMA 1
123RU     Single Stage, Manual Reset, Brass Trim, NEMA 1
123RUSST     Single Stage, Manual Reset, SST Trim, NEMA 1
123RL     Single Stage, Manual Reset, Brass Trim, NEMA 1
123RLSST     Single Stage, Manual Reset, SST Trim, NEMA 1
123RUXLW     Replacement Float, Cap, and Switch Assembly Only, No chamber for 123RU
123RLXLW     Replacement Float, Cap, and Switch Assembly Only, No chamber for 123 RL
123SST     Single Stage, Automatic Reset, SST Trim, NEMA 1
123XLS     Replacement Switch Assembly Only for 123
123SSTWP     Single Stage, Automatic Reset, SST Trim, Weatherproof Housing
CIRCUITS   2   9-51 NC SPST Mercury Switch
  3   9-51 NO SPST Mercury Switch
  103   (2) 9-51 NO DPST Mercury Switch
  127   (2) 9-51 NO DPST Mercury Switch
  151V   (2) 9-35  4-wire SPST Vibration Dampened Mercury Switch
  152   9-62  4-wire SPST Mercury Switch
  153   9-64  3-wire SPDT Mercury Switch
  156   (2) 9-51  4-wire SPST Mercury Switch
  160   9-61 NO SPST & 9-51 NC 4-wire SPST Mercury Switch
  162   9-51 NO 4-wire SPST & 9-61 NC SPST Mercury Switch
  702   9-51 NO SPST & 9-64  3-wire SPDT Mercury Switch
  705   9-51 NO SPST & 9-64  3-wire SPDT Mercury Switch
  729   9-64  3-wire SPDT Mercury Switch
  804   (2) 9-64 DPDT Mercury Switch
  7000-153   SPDT Snap Switch
OPTIONS     STW Stainless steel tag wiring
    23720 Fungus proofing special 23720
    440V 440 volt option for circuits
 
EXAMPLE 125 4820   125-4820 Liquid Level Control with SPST mercury switch closing on level fall, minimum specific gravity 0.88, cast iron body, general purpose case, switch rated at 10 amp 120 VAC/DC, 5 amp 24 VAC/DC, pressure rating 150 psi (10 bar), maximum process temperature 365°F (185°C).
CONNECTION 125     Two Stage, Automatic Reset, Brass Trim, NEMA 1
125XLW     Replacement Float, Cap, and Switch Assembly Only, No chamber for 125
125WP     Two Stage, Automatic Reset, Brass Trim, Weatherproof Housing
125SST     Two Stage, Automatic Reset, SST Trim, NEMA 1
125XLS     Replacement Switch Assembly Only for 125
125SSTWP     Two Stage, Automatic Reset, SST Trim, Weatherproof Housing
CIRCUITS   4806   (2) 9-64  6-wire DPDT Mercury Switch
  4810   9-64  3-wire SPDT Mercury Switch
  4814   (2) 9-51  NO DPST Mercury Switch
  4815   (2) 9-51  4-wire SPDT Mercury Switch
  4820   9-51  NC SPST Mercury Switch
  4821   9-51  NO SPST Mercury Switch
  4822   Consult factory for details.
  4823   2 Stage Control, (2) 9-51 Mercury Switches
  4828   (2) 9-35AV 4-wire SPDT Mercury Switch
  4829   Consult factory for details.
  4831   2 Stage Control, (2) 9-51 NO SPST Mercury Switches
  4849   2 Stage Control, (2) 9-51 NO SPST Mercury Switches
  4853   2 Stage Control, (2) 9-64  3-wire SPDT & (1) 9-51 NO SPST
  4855   2 Stage Control, (2) 9-64  3-wire SPDT & (1) 9-51 NC SPST
  4857   Consult factory for details.
  5822   Consult factory for details.
  5823   2 Stage Control, (2) 9-51 Mercury Switches
  5831   2 Stage Control, (2) 9-51 NO SPST Mercury Switches
  5849   2 Stage Control, (2) 9-51 Mercury Switches
OPTIONS     STW Stainless steel tag wiring
    23720 Fungus proofing special 23720
    2507 440 volt option for circuits
 
*Cast iron chamber is not for use with lethal or flammable substances, either liquid or gaseous.

Product Literature

Manuals

Catalog Pages

SDS

Approvals

Drawings

Questions

Question
Why is the minimum specific gravity important on the float level switches?
Answer
If a medium has a lower s.g. than the rated minimum for a float, the float will sink through the media and the switch will not operate.

Photo Downloads

You must be logged in to view this content.
Click here to login to your account.