Diaphragm Seal
Diaphragm Seal 510 – 511
This compact isolator is small enough in design to be used in confined spaces, but provides sufficient displacement to drive a wide variety of instrumentation.
Its all-welded tamperproof design prevents possible process media leakage.
Features Include:
- Compact size
- Light weight
- All-welded design
- 1,500 psi rating standard, 5,000 psi rating optional
- Continuous duty design
- Minimized fill volume
Male connections eliminate adapters/fittings.


Diaphragm Seals 100
- The top housing and diaphragm capsule are interchangeable with all Ashcroft bottom housings.
- A fill/bleed connection is standard, which permits filling the seal and instrument simultaneously after evacuation and allows the fill to flow into the completed unit.
- An O-ring, compatible with all standard fill fluids, and a Teflon back-up ring provide a seal between the diaphragm capsule and the top housing.
- The diaphragm is Teflon coated to provide an integral gasket, thus assuring a leak-tight connection between the diaphragm and the bottom housing.
- Top housing and pressure instrument are removable.
- Continuous-duty design will prevent loss of process fluid if pressure instrument is removed or fails.
The comprehensive line of Ashcroft diaphragm seals will meet a wide variety of application or installation requirements. Over 30,000 variations are possible with the s, connections and materials available.
Midi-Diaphragm Seal 311
- All welded metal construction, prevents leakage of process media
- No gaskets or bolts
- For use on pressure gauges up to 3.5″ from 60 to 1,000 psi and 4.5″ gauges 100 psi 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
- 25 NPT or 0.50 NPT instrument connections
- Type 312 furnished with 0.25 flushing connection
Type 312 not available in male process connections


Diaphragm Seal 300
- Broad selection of materials for meeting various service applications, including Teflon, Viton and Kalrez diaphragms.
- Elastomeric diaphragm is clamped securely between the top and bottom housings by clamp rings, assuring positive seal.
- Top housing is contoured to match diaphragm, minimizing distortion of the diaphragm should the pressure instrument be removed.
- Continuous duty.
- Fill/bleed connection is standard.
- Top housing and diaphragm are nonremovable.
Teflon, Viton and Kalrez diaphragms available in threaded and flanged inlet connections.