Flush Bottom Outlet Disc Valves - invented by SchuF

SchuF is the inventor (in 1923) of the Disc drain valve (Bottom Outlet Valve - BOV). They are ideal for draining tanks, reactors or pipelines containing non viscous media. They are widely used in the Petrochemical, Pharmaceutical, Fine Chemicals, Biochemical, and mineral refining industries.

Disc Bottom Outlet Valve

Model 25BS Disc rising bottom outlet valve, Photo:©SchuF


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Disc Valve Model Numbers

Model 18 + Model 24 are disc lowering variants 

Model 19 Model 25 are disc rising variants


Disc valve applications - as Drain valves or Feeding valves

Disc valves are most commonly used for the dead space free draining and feeding of vessels, reactors and pipelines. They are especially suited to low viscosity materials, or where slower vessel drainage is unproblematic.

The shorter stroke results in smaller, lighter and faster actuators, saving cost and weight. The disc rising valve is normally a flow to close design, aiding sealing performance.

The disc lowering valve Model 24 can be used on vessels with agitators as it is non intrusive. They are also widely used for driers, mixers, and filters.

Disc bottom outlet valve

Disc drain valve with PTFE seat

 idsc bottom outlet valve  Disc BOV with PTFE seat



Key Characteristics of SchuF Disc Drain Valves

  • Available as a disc lowering or disc raising valve

  • Designed to allow complete draining of the vessel and valve

  • No Deadspace, no sharp corners or edges

  • No leakage to atmosphere options (with stuffing box, metal/PTFE bellow or diaphragm seal to atmosphere)

  • Zero contamination features – Sterile valve also available

  • All valves have a Positive seal

  • Cleaning in service through flushing port(s)

"Made to fit" -
x and d1 dimensions

Disc valve combined 
with sampling valve

 Disc drain valve seat dimensions
 BOV and sampling valve combination




Disc Drain Valve Options

  • Automatic Crust Breaking with Disc Rising versions

  • Available in a fire safe version with certification to BS 6755 Pt.2 (ISO 10497)

  • Can be combined with a wafer type sampling valve

  • Temperature sensors are possible through the valve

  • GMP (Good Manufactoring Practice) and CIP (Clean In Place) conformant


Sizing of Disc Valves and Material Choice

Depending on application, sizes from one inch to six inch and larger on request. Please see attached PDF files for more detailed dimension information.

Disc Valves are available in all materials including cast-steel, stainless steel, all nickel based alloys, Titanium, Zirconium and others. They can also be PTFE and glass lined.


Contact Us

For further information, pricing or a brochure, please contact us via e-mail: valves@schuf.com

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Video gallery
A video showing the operation of a recently-manufactured SchuF powder-sampling Valve is now available-please click the link below, which will take you to the Vimeo video-sharing website. The video will begin automatically. more