What makes diaphragm valves better than ball or butterfly valves for abrasive slurries?

The diaphragm provides a flexible sealing surface that is not damaged by solids. Unlike ball or butterfly valves, there are no seats or seals in the flow path that can erode or trap particles, ensuring reliable shut-off even with abrasive media.

Can Saunders A Type valves be serviced without removing them from the pipeline?

Yes. The three-part construction (body, bonnet, diaphragm) allows diaphragm replacement and actuator changes in-line, reducing downtime and maintenance costs.

What diaphragm and lining materials are available for chemical service?

Multiple options are available including natural rubber, EPDM, Neoprene, Butyl, Hypalon, and PTFE-faced diaphragms. Body linings include rubber and various polymers. Material selection depends on process fluid, temperature, and pressure. Contact PC Engineering for compatibility guidance.

Are these valves suitable for vacuum applications?

Yes. Saunders diaphragm valves provide leaktight closure under both pressure and vacuum conditions, making them suitable for vacuum lines and degassing systems.

What actuation options are available for automated process control?

Pneumatic actuators (EC, SSC, ECX, EV, ESM series) are available for on/off and modulating control. Manual handwheel bonnets are standard; position indicators and limit switches can be fitted as accessories.

CRANE CHEMPHARMA & ENERGY · INDUSTRIAL DIAPHRAGM VALVES

Saunders A Type Industrial Diaphragm Valves – Crane ChemPharma

Name: Saunders A Type Industrial Diaphragm Valves – Crane ChemPharma
Brand: Crane ChemPharma & Energy

Saunders A Type diaphragm valves by Crane for corrosive & abrasive applications. 100% leaktight, DN15-DN500. Get specs & quote from PC Engineering India.

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Saunders Industrial Diaphragm Valves - Crane ChemPharma

Overview

The Saunders A Type diaphragm valve is a weir-type valve designed for reliable shut-off and flow control in corrosive, abrasive, and high-purity process applications. Originally invented by P.K. Saunders in 1928, this valve design has become the industry standard for applications where conventional ball, butterfly, or globe valves fail due to erosion, corrosion, or contamination concerns.

The valve operates by lowering a flexible diaphragm onto a weir (raised seat), providing 100% leaktight closure even after thousands of cycles. All wetted parts are isolated from the bonnet mechanism, eliminating contamination risks and reducing maintenance. The pocketless, cavity-free flow path minimizes fluid entrapment and supports self-draining installations.

Saunders A Type valves are available in flanged and screwed configurations across a wide size range (DN8 to DN500), with multiple body materials, linings, and diaphragm options to match specific process requirements.

Key Features

100% leaktight closure on pressure and vacuum, even with entrained solids
Pocketless weir design for smooth, contamination-free flow and excellent throttling control
Diaphragm isolates all bonnet components from line media — no packing glands or seals exposed to process fluid
Three-part construction allows in-line maintenance and actuator retrofitting without pipeline removal
Wide material selection for bodies (cast iron, SG iron, cast steel, gunmetal, stainless steel) and linings
Multiple diaphragm materials for chemical compatibility and extended service life
Self-draining installation capability for hygienic or critical process systems
Manual, pneumatic, and control actuation options available

Specifications

Parameter	Value
Valve Type	Weir-type diaphragm valve
Size Range (Flanged)	DN15 to DN500
Size Range (Screwed)	DN8 to DN50
Body Materials	Cast Iron, SG Iron, Cast Steel, Gunmetal, Stainless Steel
Lining Options	Various (rubber, PTFE, and other polymers available)
Diaphragm Materials	Multiple elastomers and PTFE-faced options
End Connections	Flanged, screwed, or weld ends to international standards
Actuation	Manual handwheel, pneumatic (EC, SSC, ECX, EV, ESM actuators)
Standards	PED/CE marked; consult factory for specific approvals

Applications

Saunders A Type diaphragm valves are widely used in industries where leaktight shut-off, corrosion resistance, and low maintenance are critical:

- Chemical and petrochemical plants – acids, alkalis, solvents, and aggressive chemicals - Mining and mineral processing – abrasive slurries, tailings, and ore handling - Water and wastewater treatment – dosing, isolation, and process control - Fertiliser production – corrosive and crystallising fluids - Marine and firefighting systems – seawater, hydrant valves - Pharmaceutical and food processing – high-purity and hygienic applications (AFP variant) - Power generation – cooling water, chemical dosing

Product Images

Saunders A Type Diaphragm Valve Features

Frequently Asked Questions

Get a Quote

Contact PC Engineering for pricing, availability, and technical support for Saunders A Type Industrial Diaphragm Valves. Call us or fill in our inquiry form — our engineers will respond within 24 hours.

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