Ashcroft� Diaphragm Seals
Diaphragm Seals (PDF 1.1MB) Technical Data (PDF 580kB) 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 types, connections and materials available.
	Type 100 Capsule Diaphragm Seal 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. A Viton 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. A thin Teflon PTFE gasket between the diaphragm and bottom housing assures a leak-tight corrosion resistant seal even at high pressure. Top housing and pressure instrument are removable. Continuous-duty design will prevent loss of process fluid if pressure instrument is removed or fails. Available with the following process connections: * Threaded * Threaded w/ Flushing Connection * Raised Face Flange * Raised Face Flange w/ Flushing Connection * Saddle * In-Line Threaded * In-Line Flanged * In-Line Socket Weld * In-Line Butt Weld
	Type 200 Welded or Bonded Diaphragm Seal WELDED 200 - Teflon gasketed, continuous-duty diaphragm capsule is welded to the top housing, which is then clamped to a bottom housing. Fill/bleed connection is standard. Top housing and pressure instrument are removable. Available in same process connections, materials, types and sizes as the type 100 capsule design. Top housing is interchangeable with all standard Ashcroft� bottom housings. BONDED 200 - Similar in construction, materials, and product features to the type 300 clamped diaphragm seal, the diaphragm in the Type 200 seal is bonded permanently to the top housing - and is the removable type. Available with the following process connections: * Threaded * Threaded w/ Flushing Connection * Raised Face Flange * Raised Face Flange w/ Flushing Connection * Saddle * In-Line Threaded * In-Line Flanged * In-Line Socket Weld * In-Line Butt Weld
	Type 300 Clamped Diaphragm Seal 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 non-removable. Teflon, Viton and Kalrez diaphragms available in threaded and flanged inlet connections. Available with the following process connections: * Threaded * Threaded w/ Flushing Connection * Raised Face Flange * Raised Face Flange w/ Flushing Connection * In-Line Threaded
	Type 400 All Welded Diaphragm Seal Recommended for use where clamped joints are not acceptable. Assists in controlling plant emissions by helping prevent potential leakage of hazardous chemicals. Prevents inadvertent disassembly. All-stainless steel construction is standard. Other materials available. Available with the following process connections: * Threaded * Threaded w/ Flushing Connection * Raised Face Flange * Raised Face Flange w/ Flushing Connection
	Type 500 All Welded Diaphragm Seal Recommended for use where clamped joints are not acceptable. Assists in controlling plant emissions by helping prevent potential leakage of hazardous chemicals. Prevents inadvertent disassembly. All-stainless steel construction is standard. Other materials available. Available with the following process connections: * Threaded * Threaded w/ Flushing Connection
	Type 702/703 Flanged High Displacement Isolator For pressure instruments ranging from 30 in.H₂O to 750 psi. Used in instruments with large displacement actuators. For applications requiring an impermeable metallic diaphragm. Available in many material combinations. Diaphragm electron beam welded to isolator body. Furnished with fill/bleed connection.
	Type 740/741 Threaded High Displacement Isolator For pressure instruments ranging from 30 in.H₂O to 750 psi. Used in instruments with large displacement actuators. For applications requiring an impermeable metallic diaphragm. Available in many material combinations. Diaphragm electron beam welded to isolator body. Furnished with fill/bleed connection.
	Type 310/315 All-Welded "Mini" Diaphragm Seal Compact size to fit space restricted areas. Designed to protect transducers, mini-switches and 3.5" or smaller pressure gauges from corrosion, plugging or freeze-up. All-welded metal construction prevents leakage of process media. Rated for 2500 psi at 100�F. Fill/bleed connection is standard. Available in Male or Female. Flushing Connection with Type 315.
	Type 311/312 All-Welded "Mini" Diaphragm Seal All welded metal construction, prevents leakage of process media. No gaskets or bolts. For use on pressure gauges up to 3.5" from vacuum to 1000 psi, and 4.5" gauges 100 psi to 1000 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 female, 1/4"-1/2" NPT male process connections. 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
	Type 320 Quick-Connect Diaphragm Seal The Ashcroft� Type 320 quick-connect diaphragm seal is designed especially for those applications that require ease of dismantling and reassembly and do not require a 3A standard rating in accordance with sanitary standard 74-00. Typical applications include the pharmaceutical, dairy, food processing, biotechnology, and filtration markets. Also included are breweries, distilleries, wineries, and citrus juice production plants. Standard features include 316L stainless steel diaphragm welded to a 316L stainless steel top housing, fill/bleed connection, top housing and pressure instrument removable from process, compatible with Tri-Clover and Cherry Burrell S line connections.
	Type 330 All Welded Flush Mini-Diaphragm Seal All welded metal construction, prevents leakage of process media. Flush design eliminates pockets that could cause clogging or buildup of process media. Diaphragm area easy to clean up. Provided with a 1" MNPT process connection. Compact size to fit space-restricted areas. No gaskets or bolts. For use on pressure gauges up to 3.5" from vacuum to 1000 psi. Top housing and diaphragm material 316L stainless steel. 1/4" NPT and 1/2" NPT instrument connection. Adds an additional 1% tolerance to the gauge.