Mercoid 液位開關(guān) 1251/1253/1254
Leak proof all welded heavy duty carbon steel bodies coupled with snap action or mercury switches provide reliable, long term service for compatible liquids. 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. A variety of snap action or mercury switches in SPST, SPDT, DPDT or DPST configurations will satisfy most electrical requirements. These switch assemblies are contained in NEMA 1 general purpose, NEMA 4X weatherproof, NEMA 7, 9 groups B, C, D, E, F, G, explosion-proof or explosion-proof – vapor proof enclosures.
C1-40:Minimum specific gravity 0.40. Process pressure 1250 psi (86 bar) at 100°F (38°C) to 500°F (260°C).
Temperature Limit:Ambient Temperature: 212°F (100°C); Process Temperature: up to 500°F (260°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:Combination 1" NPT/socket weld hubs or flanges. See Model Chart.
Enclosures:G: painted steel and aluminum; WT: painted steel, aluminum and neoprene; E: aluminum; EV: aluminum and neoprene.
Wetted Parts:C1 construction. Chamber: carbon steel; Trim: 303SS, 304SS, 316SS and 430SS.
Weight:1251: 40 lb (18 kg); 1253: 50 lb (22.7 kg); 1254: 57 lb (25.8 kg).
Suggested Specifications:
Liquid level control shall be 1251 (1253) (1254) Series with 1" combination NPT/socket weld hub (flanged) process connections. Chamber shall be welded and suitable for operation at 1250 psig (86 bar) and 500°F (260°C) with a minimum specific gravity of 0.40. Circuit shall be hermetically sealed snap action (mercury) switch (SPST) (SPDT) (DPDT). Enclosure shall be general purpose, (explosion- proof) (explosion-proof – vapor proof). Switch mechanism shall be gravity return and shall be activated by a stainless steel float.
Model Chart
| EXAMPLE | 1251 | WT | 7810 | C1 | 40 | 1251-WT-7810-C1-40 Liquid Level Control, weatherproof enclosure, SPDT snap switch, fixed deadband, automatic reset, operating pressure 1250 psig (86 bar) at 100°F (38°C), 1250 psig (86 bar) at 500°F (260°C), side/bottom process connections, 1" NPT/socket weld hubs, minimum specific gravity 0.40. | |
| CONNECTION | 1251 | One Horizontal and One Vertical 1" Socket Weld or 1" NPT Combination Hub | |||||
| 1253 | One Vertical and One Horizontal Flanged Connection | ||||||
| 1254 | Two Vertical Flanged Connections | ||||||
| 1254T | |||||||
| 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 | ||||||
| 78XXHM | Hermetically Sealed 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 | |||||
| C216 | 316SS Body | ||||||
| HFC1 | Heat Fins & Carbon Steel Body | ||||||
| HFC216 | Heat Fins & 316SS Body (1251, 1253 only) | ||||||
| MINIMUM SPECIFIC GRAVITY | 40 | 0.40 Specific Gravity (1251 only) | |||||
| 140 | 0.40 Specific Gravity & 150# Flange (1253, 1254 only) | ||||||
| 340 | 0.40 Specific Gravity & 300# Flange (1253, 1254 only) | ||||||
| 640 | 0.40 Specific Gravity & 600# Flange (1253, 1254 only) | ||||||
| OPTIONS | R | Manual Reset, Single Stage | |||||
| R1 | Manual Reset, Lower Stage 2-Stage Control | ||||||
| R2 | Manual Reset, Upper Stage 2-Stage Control | ||||||
| R3 | Manual Reset, Both Stages 2-Stage Control | ||||||
| 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 |
