Series 291/293/294 Welded Chamber Level Control

Single Stage, Low Cost, Hermetically Sealed Snap Switches

Inexpensive yet rugged construction in a welded chamber control. The 291 SERIES is specifically designed for single stage operation where pressure does not exceed 350 psig (24 bar) at 100°F (38°C) or 300 psig (21 bar) at 600°F (315°C) available with a variety of hermetically sealed snap switch or mercury switch circuits protected by a general purpose, weatherproof or explosion-proof enclosure and will accommodate specific gravities down to 0.60.

Product Applications

  • Refineries
  • Chemical Plants
  • Power Generating Stations
  • Water Treatment Facilities

Models & Ordering

Build Your Custom Part. Use our Product Configurator

Specifications

C1-60:
Minimum specific gravity. Process pressure 350 psig (24 bar) at 100°F (38°C), 300 psig (21 bar) at 600°F (315°C).
Switch Type:
Snap action or mercury. See Model Chart.
Electrical Rating:
See Model Chart.
Wiring Connections:
G, WT or E enclosure, terminal block. EV enclosure 18" (460 mm) leads.
Process Connection:
1" NPT (socket weld hubs or flanged optional).
Enclosures:
G: painted steel and aluminum; WT: painted steel, aluminum and neoprene; E: aluminum; EV: aluminum and neoprene.
Wetted Parts:
C1 construction, carbon steel, 303SS, 304SS, 430SS.
Weight:
291: 10 lb (4.5 kg); 293: 15 lb (6.8 kg); 294: 17 lb (7.7 kg).

Model Chart

 
EXAMPLE 291 WT 7810 C1 60   291-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.
CONNECTION 291           One Vertical and One Horizontal 1" NPT
293           One Vertical and One Horizontal Flanged Connection
294           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)
    48XXBN       Single Stage Mercury Switch, see chart A
    78XXBN       Single Stage, Snap Switch, see chart B
    98XXBN       Single Stage, High Capacity DC Snap Switch, see chart B
CHAMBER MATERIAL       C1     Carbon Steel Body
      C216     316SS Body
MINIMUM
SPECIFIC
GRAVITY
        60   0.60 Specific Gravity (291 only)
        160   0.60 Specific Gravity & 150# Flange (293, 294 only)
        360   0.60 Specific Gravity & 300# Flange (293, 294 only)
OPTIONS           H2 H2 Socket Weld Hub (291, steel housing only)
          STW SS Tag Wired
          01 Breather Only (E-Housing only)
          02 Drain Only (E-Housing only)
          12 Breather & Drain (E-Housing only)
          23720 Fungus Proofing



CHARTS A & B - ELECTRICAL CIRCUITS AND RATINGS

 

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

†Available on special order, change 1st digit in ordering code from 4 to 5 or 7 to 8, i.e., -4820 becomes -5820, -7810 becomes -8810, etc.
‡10 amp inductive (polarized) at 125 VDC.
*Electrically Independent.
**Resistive.

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.

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