Diaphragm Valves


KB Diaphragm Valves

Straight-Through Type

PK Saunders invented the original diaphragm valve in 1928 in the then known West Rand gold fields of Johannesburg. Since then, we have developed our range through innovative designs and by using the latest materials technology. As a result, Saunders diaphragm valves have gained an excellent reputation for versatility and reliability establishing a presence in the mining and every process industry sector. Today there are millions of Saunders diaphragm valves, manufactured by Dynamic Fluid Control and supplied by our distribution partners to South and Southern African markets.

Saunders full bore KB type valve, with their smooth non-turbulent body design have proved to be outstanding in resisting the erosive affects of corrosive/abrasive line media. In addition, the full bore concept is designed for minimum flow resistance whilst allowing rodding out and easy cleaning.

The flexible diaphragms ensure consistent leak tightness even when solids, powders and dry media are present. A range of rubber linings are available for the more exacting corrosive and abrasive applications to a maximum working pressure of 10 bar.
The KB valve can be installed in any position without affecting its operation. We recommend six times pipe diameter from pump or bend. Bonnet assembly lubricated for long life. Needs no further grease. The indicator lip seal stops the ingress of dust, dirt and atmospheric contaminates.
Three part design allows maintenance and actuator retrofitting without removing the valve body from the pipeline. Extended life, reliability and safety, combined with essentially simple design, result in low maintenance and low cost of ownership.

Features and benefits of the KB body with RHI Bonnet

  • Straight through body, high flow, low pressure drop
  • Low maintenance
  • Rising handwheel indicator
  • Immediate indication of open/close position
  • Leak tight by design
  • Flexible closure even with solids present
  • Only two wetted parts
  • Bonnet working parts isolated from line media
  • Specially developed linings and diaphragms available
  • Indicator sleeve (lubrication reservoir)
  • Rolled thread spindle
  • More compact than the previous model
  • Better resistance to corrosion/abrasion due to the sealed bonnet
  • Weighs less for easy handling
  • Space saver for difficult installations
  • Lower open and closing torques

A valve package for corrosive and abrasive applications

Cast Iron Ductile Iron (SG) Strength, low cost non corrosive duties DN15-DN350 -20° to 175°
  • Soft (AAL)
  • Hard (Ebonite) (HRL)
  • Butyl (BL)
  • Neoprene (NL)
Economic handling of corrosive & abrasive media Abrasive duties Acid, chlorinated water, moist chlorine Mineral acids, & slurries Abrasive duties where hydrocarbons are present DN25 - DN350  
  • 10° to 85°
  • 10° to 85°
  • 10° to 110°
  • 10° to 105°
Borosilicate Glass Excellent for strong acids, halogens DN25 - DN200 -10° to 175°
Halar" Excellent resistance to mineral and oxidising acids inorganic bases, salts DN25 - DN350 -10° to 150°
Fusion Bonded Epoxy FBE Potable water applications DN25 - DN350 -20° to 80°

Halar is the registered trademark of AUSIMONT UK Ltd

Proofed against corrosion and erosion in hostile environments

A Abrasives in slurry or dry powder form. DN15 - DN350 - 40° to 90°
B Acid and alkalis. Up to 85% sulphuric acid at ambient temperatures. Hydraulic hydrochloric phosphoric acids, caustic alkalis and many esters. Sea water, very low vapour and gas permeability. Insert gases and many industrial gases. DN15 - DN350 - 30° to 90°
C Salts in water, dilute acids and alkalis, abrasives. DN15 - DN350 - 10° to 90°
226 Paraffinic and aromatic hydrocarbons, acids, particularly concentrated suplhuric and chlorine applications. Not recommended for ammonia and its derivatives or for polar solvents, e.g. acetone. DN15 - DN250 - 5° to 140°
237 Good acid and ozone resistance certain chlorine services. DN15 - DN350 - 0° to 90°
300 For hot water services applications involving steam sterilisations, therefore, ideally suited for brewing and pharmaceutical applications. For services involving continuous high temperature/pressure combinations consult our technical department. DN15 - DN350 - 20° to 120°
425 Salts in water, drinking water. DN15 - DN350 - 40° to 100°

Key to grade letters / materials: A - Natural Rubber | B - Butyl | C - Nitrile | 226 - Fluororubber | 300 - Butyl | 237 - Hypalon | 425 - Epdm