LD-Series NEMA 4 Watertight Differential Pressure Switch
The AshcroftĀ® LD differential pressure switch is designed for applications requiring high reliability, safety and accuracy. Its straight forward design facilitates easy field installation and calibration, making it most suitable for differential pressure control, safety shutdown or alarm operations where two independent set points or adjustable deadbands are required.
Key Features:
- Designed for easy field installation and wiring of microswitches
- Ranges from 30 in. H2O to 400 PSID
- Wide selection of switch elements
- Stainless steel, Buna, Viton, Teflon and Monel diaphragms available for compatibility
- Adjustable setpoints from 15%-100% of range
- Fixed or adjustable deadbands
- FM, UL, CSA and CE approved
- RoHS Compliant
Applications:
Process Market:
Refineries
Chemical and Petrochemical Plants
Pulp and Paper Mills
Power Plants
Steel Mills
Water and Sewage Treatment Facilities
Industrial Market:
Pumps, Compressors and Turbines
Dairies and Breweries
Boilers and Burners
Reverse Osmosis Systems
Filters and Presses
Paint Spraying Equipment
Specialized OEM Equipment
Medical and Life Sciences Market:
Pharmaceutical Plants
Product Information
Specifications
- Setpoint
- Independent setpoint, fixed deadband
- Single setpoint, adjustable deadband
- Single setpoint, fixed deadband
- Setpoint Repeatability (Accuracy)
- ±1% of span (Additional setpoint shift of ±1% of range per 50°F from initial setpoint set at 70°F typical)
- Deadband
- Fixed or adjustable
- Enclosure Ratings
- NEMA 4X / IP66
- Enclosure Material
- Epoxy coated aluminum
- Pressure Connection
- 1/4 NPT Female
- 1/2 NPT Female
- 1/4 NPT Female and 1/2 NPT Male Combination
- Electrical Termination
- ¾ NPT Female (STD.)
- Diaphragm/Actuator Material
- Buna-NĀ®, TeflonĀ®, VitonĀ®, 316L stainless steel, or MonelĀ®
- Pressure Ranges
- 30 in H2O differential thru 400 psid
- Ambient Temperature Range
- -20°F to 150°F (-29°C to 65°C)
- Process Temperature
- 0°F to 150°F (Buna N or Teflon diaphragm)
- 0°F to 300°F (Stainless steel or Monel diaphragm)
- 20°F to 300°F (Viton diaphragm)
Data Sheets:
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Resources & Tools
Materials Selector
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Unit Converter
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Product Information
To learn more about the technical details for options available, review our product information (PI) pages.
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Ashcroft is a trusted source for pressure, temperature, and test instruments around the world. Learn more about how we can help you protect your people, processes, and profits.

