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

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Models & Ordering

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
CHAMBER MATERIAL				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.