Series 251/253/254 Welded Chamber Level Control

Welded Chamber Level Control External Mount Pressure to 1250 psig (86 bar), Hermetically Sealed Switches, Temperature to 750°F (400°C), Explosion-Proof Housings

External Mount Pressure to 1250 psig (86 bar), Hermetically Sealed Switches, Temperature to 750°F (400°C), Explosion-Proof Housings

Time proven magnetic head leak proof construction combines with a heavy duty welded chamber to provide excellent reliability for control of compatible liquids. Operating pressures of 1250 psig (86 bar) at 650°F (345°C) and 750 psig (52 bar) at 750°F (400°C) are standard. The use of an external magnet reduces the possibility of magnetic particle build up inside the armature tube and subsequent loss of operation as may occur with the internal magnet repulsion design. The controls feature carbon steel bodies and stainless steel internal trim. Process mounting configurations include either side/bottom combination 1" NPT/socket weld hubs, side/bottom flanges or side/side flanges. A variety of hermetically sealed snap action or mercury switches are available in SPST, SPDT, or DPDT action for single or two stage operation. Mercury or Gold alloy snap action contacts are suitable for low current DC applications. A full range of switch enclosures are offered. Many chamber, enclosure and switch combinations are UL approved.

Product Applications

  • Refineries
  • Chemical Plants
  • Power Generating Stations
  • Water Treatment Plants
  • Mixing Systems
  • Scrubbers
  • Accumulators
  • Condensate Recovery
  • Industrial Tanks and Vessels
More Information
Model Chart
EXAMPLE251WT7810C160 251-WT-7810-C1-60 Liquid Level Control, welded carbon steel chamber, weatherproof enclosure, SPDT snap switch, fixed deadband, automatic reset, operating pressure 350 psig (24 bar) at 100°F (38°C), 300 psig (21 bar) at 600°F (315400°C), side/bottom 1" NPT, minimum specific gravity 0.60.
CONNECTION251     One Vertical and One Horizontal 1" NPT
253     One Vertical and One Horizontal Flanged Connection
254     Two Vertical Flanged Connections
ENCLOSURE  G    General Purpose, NEMA 1
 WT    Weatherproof, NEMA 3R, 4, 4X
 E    Explosion-proof, NEMA 7, 9, Class I Groups B, C, D, Class II Groups E, F, G
 EV    Explosion-proof/Vapor-proof, NEMA 7, 9, Class I Groups B, C, D, Class II Groups E, F, G
CIRCUITS
(for electrical circuits
see charts A & B below)
  48XX   Single Stage Mercury Switch, see chart A
  48XX-XX   Two Stage, Mercury Switch, see chart A
  78XX   Single Stage, Snap Switch, see chart B
  78XX-XX   Two Stage, Snap Switch, see chart B
  98XX   Single Stage, High Capacity DC Snap Switch, use heat fins (HF) if process temperature exceeds 350°F (177°C), do not exceed 450°F (232°C), see chart B
  98XX-XX   Two Stage, High Capacity DC Snap Switch, use heat fins (HF) if process temperature exceeds 350°F (177°C), do not exceed 450°F (232°C), see chart B
CHAMBER MATERIAL   C1  Carbon Steel Body
   HFC1  Heat Fins, Carbon Steel Body
   C216  316SS Body
   HFC216  Heat Fins, 316SS Body (251 only)
   C217  316SS Housing with Shield (251 only)
MINIMUM
SPECIFIC
GRAVITY
    60 0.60 Specific Gravity (251 only)
    75 0.75 Specific Gravity (251 only)
    160 0.60 Specific Gravity & 150# Flange (253, 254 only)
    175 0.75 Specific Gravity & 150# Flange (253, 254 only)
    360 0.60 Specific Gravity & 300# Flange (253, 254 only)
    375 0.75 Specific Gravity & 300# Flange (253, 254 only)
    660 0.60 Specific Gravity & 600# Flange (253, 254 only)
    675 0.75 Specific Gravity & 600# Flange (253, 254 only)
OPTIONS     RManual Reset, Single Stage
     R1Manual Reset, Lower Stage of 2-Stage Controls
     R2Manual Reset, Upper Stage of 2-Stage Controls
     R3Manual Reset, Both Stages of 2-Stage Controls
     STWSS Tag Wired
     01Breather Only (E-Housing only)
     02Drain Only (E-Housing only)
     12Breather & Drain (E-Housing only)
     23720Fungus Proofing




CHARTS A & B - ELECTRICAL CIRCUITS AND RATINGS

 

SWITCH TYPE
SWITCH ACTION
ELECTRICAL RATINGS IN AMPS
ORDERING CODE
AC
DC
SINGLE STAGE
TWO STAGE
120V
240V
440V
30V
125V
250V
LOWER
UPPER
CHART A
Mercury Contacts
SP-ST open on level FALL
10
5
3†
 
10
5
-4821
-4821
-21
SP-ST open on level RISE
10
5
3†
 
10
5
-4820
-4820
-20
SP-DT one switch
4
2
1†
 
4
2
-4810
-4810
-10
SP-DT two switches E.I.*
10
5
3†
 
10
5
-4815
-4815
-15
DP-ST two switches E.I.* open on level FALL
10
5
3†
 
10
5
-4813
-4813
-13
DP-ST two switches E.I.* open on level RISE
10
5
3†
 
10
5
-4814
-4814
-14
DP-DT two SP-DT switches
4
2
1†
 
4
2
-4806
-4806
-06
CHART B
snap action contacts
SP-DT one switch
12
5
3†
 
0.5**
0.25**
-7810
-7810
-10
DP-DT two SP-DT switches
12
5
3†
 
0.5**
0.25**
-7806
-7806
-06
SP-DT one hermetically sealed switch
5
5
 
5**
 
 
-7810HM
-7810HM
-10HM
DP-DT two hermetically sealed SP-DT switches
5
5
 
5**
 
 
-7806HM
-7806HM
-06HM
DP-DT two SP-DT switches
10
3
 
 
10‡
3‡
-9806
-9806
-06
SP-DT one switch
10
3
 
 
10‡
3‡
-9810
-9810
-10
DP-DT Two SP-DT switches
2
2
 
 
0.4**
0.25**
-1006
-1006
-06
SP-DT one switch
2
2
 
 
0.4**
0.25**
-1010
-1010
-10

C1-75:Minimum specific gravity 0.75. Process pressure 1250 psig (86 bar) at 100°F (38°C), to 650°F (345°C). 750 psig (52 bar) at 750°F (400°C).*
*Heat fins and/or high temperature switches should be considered for process temperatures above 500°F (260°C).
Switch Types:Snap action or mercury.
Electrical Rating:See Model Chart.
Wiring Connections:G, WT or E enclosure, terminal block. EV enclosure 189 (460 mm) leads.
Process Connections:Combination 1" NPT/socket weld hubs or flanges. See model chart.
Wetted Parts:C1 construction, carbon steel, 303SS, 304SS, 316SS, 430SS. (Optional 316SS with 430SS).
Enclosures:G painted steel and aluminum. WT, painted steel, aluminum and neoprene. E, aluminum. EV, aluminum, neoprene.
Weight:251: 40 lb (18 kg); 253: 50 lb (22.7 kg); 254: 57 lb (25.8 kg).