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The Ashcroft 311 and 312 midi-diaphragm seals or isolation devices are used in confined areas to protect measuring instruments.
Used to ensure process compatibility, they are also applied when process media exhibits high temperature and pulsation.
This model is ideal with limited space installations.
Features- All-welded metal construction, prevents leakage of process media
- No gaskets or bolts
- For use on pressure gauges up to 3-1/2" from vacuum to 1,000 psi and 4-1/2" gauges 30 to 1,000 psi
- Top housing material 316L stainless steel standard
- Diaphragm materials in 316L stainless steel, Hastelloy® C and tantalum
- Bottom housing materials in 316L stainless steel and Hastelloy® C
- 1/4" NPT or 1/2" NPT instrument connections
- Type 312 furnished with 1/8" NPT flushing connection
- Type 312 not available in male process connections
Specifications
Brand
Applications
- Biogas & Biodiesel
- Chemical & Petrochemical
- Oil & Gas Applications
- Oil & Gas Fracking
- Refineries
- Water & Wastewater
Approvals & Certifications
- CRN
- GOST
Diaphragm Material
- 316L Stainless Steel
- Hastelloy® C-276
- Tantalum
Enclosure, Body Material
- 316L Stainless Steel
- Hastelloy® C-276
Fill Material
- Glycerin
- Halocarbon
- Silicone
- Syltherm
NACE & NIST
- NACE
NPT Connection
- 1" NPT Female
- 1" NPT Male
- 1/2" NPT Female
- 1/2" NPT Male
- 1/4" NPT Female
- 1/4" NPT Male
- 3/4" NPT Female
- 3/4" NPT Male
Pressure Range
- 4-1/2" Gauge psi: 30 to 1,000 (kPa: 206.8 to 6,895, bar: 2 to 68.95)
- Up to 3-1/2": Vacuum to psi: 1,000 (kPa: 6,894, bar: 69)
Temperature Range
- -21° to 398.9° C (-70° to 750° F)
Documentation
Industry Brochure
Product Information
- Attaching 2 1/2" and 3 1/2 1009 Gauges to Diaphragm Seals pdf 817 KB
- Attaching Diaphragm Seals to Low Pressure Gauges pdf 1,008 KB
- Chlorine, Bromine and Fluorine Recommended Diaphragm Materials pdf 1.1 MB
- Diaphragm Seal with Dampening Device pdf 664 KB
- Diaphragm Seal with Vacuum Gauge pdf 663 KB
- Failure and Corrective Steps for Diaphragm Seals pdf 668 KB
- High Temperature Fill Fluid pdf 668 KB
- Instruments Not Available with Diaphragm Seals pdf 668 KB
- Minimum, Maximum and Pressures Recommended Diaphragm Materials pdf 651 KB
- Temperature Error pdf 1.8 MB
- Volumetric Displacement pdf 2.4 MB
