740-741 High-Displacement Diaphragm Seals

The Ashcroft® 740 and 741 high-displacement diaphragm seals are used with low-ranged instruments or high static pressure differential pressure gauges with low differential pressure. Used to ensure material compatibility, they are also applied when process media exhibit pulsation or the potential to clog an instrument connection. An ideal product for satisfying low pressure measurement needs.

Key Features:
  • Wide selection of diaphragm and lower housing materials
  • Enlarged welded diaphragm; high displacement allows high sensitivity to pressure fluctuations
  • Flush port (type 741) provides easy cleaning / flushing for process media prone to clogging

Process Market:
Oil and Gas
Chemical and Petrochemical
Water and Wastewater

Process Applications:
Oil and Gas Fracking
NACE Compliant Processes (Sour Gas Separation)
Biogas and Biodiesel


Certifications & Approvals

Data Sheets & Instruction Manuals

Drawings & Product/Technical Information

Resources & Tools

Min/Max Guide

IMPORTANT! When selecting an instrument, refer to the Min/Max Guide (PI Page) for compatibility with this diaphragm seal.

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Materials Selector

Use the selector to review compatible wetted materials and requirements of your application.

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Unit Converter

Need to convert measurement units? Check out our quick and easy tool to convert pressure, temperature and flow units of measure.

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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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Contact Ashcroft

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.

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