Float-operated Valves

• BS 1212 (50" MAX size)
• Part 1 (Portsmouth) NOT suitable for WC cisterns
• Part 2(~£8)- diaphragm type, brass
  
• Part 3 (~£7) diaphragm type, plastic
  
• Part 4 (Torbeck) used in WC (Equilibrium)
  
  
• 4 ½’’ Ball Valve (~£3) with 15mm valve
• Backplate - fixed at the point of connection of FOV
  • can fix a hammering noise
• Tank Connector (15mm ~ £1.63) - used to make connection to FOV
  
• High and Low-pressure type (different size of the orifice)
• Delayed Action Float-operated Valve - essential with hydropneumatic pumped system as it is reducing a number pump's stop/start
  
  

Stop Valve

• BS 1010
• Used for shutting off the flow of water in a pipe
• For higher pressure applications
• PREFERED position 150mm above the floor level
  
  

Gate Valve

• BS 5154
• Used for distributing pipes and as the main stop cock
  
• Flanged Gate Valve (2"~ £110)
  
  

Plug Valves

• Spherical Plug Valve (22mm~£3; BS 6675) - Used before single outlet
  
  • Lever-operated pattern
  • Screwdriver-operated pattern
• Plug Valve  for above and below ground use (25mm~£36; BS 2580)
  
  
  

Drain Valve

• BS 2879-2
• Screwdown Type is only allowed by Water Regulations
• 150mm from the floor on a rising main
• Replacement of "O"-ring Packing Gland
  
  

Check Valves

• Single Check Valve
  
  • BS 6282
  • prior to water softener; unvented heating systems; sprinkler system supply; downstream of meters, PRVs
  • Disc and Flap types - for low pressure
  • Spring-assisted Recoil Valve - for high pressure
• Double Check Valve
  
  • hose tap; standpipes; Portsmouth; shower fitting
• Shower Check Valve – unconstrained shower hose
  
  
• Pressure Reducing Valve
  • small end denotes higher pressure on the drawing
  • more about PRV
    
    
• Reduced Pressure Zone Valve RPZ
  
  • the lowest relief outlet SHOULD terminate with AA air gap, MIN 300mm above the ground level
  • MUST only be installed by a competent person, completed the special course
  • MUST be tested every year with a special test equipment
  • Signed Certificate of Competence MUST be sent to the customer and a copy to the Water Undertaker
  • SHOULD be provided with a drain pipe via a Tundish
  • MUST be away from any electrics
  • Fix Single Check Valve if flactuation occurs
    
    
• Pressure Flushing Valve - is not allowed to be installed in a domestic residential dwelling