McAlpine Tubular Swivel Anti-Syphon inchP inch Trap Available in 1.25 Inch, 1.50 Inch, and 2 inch sizes

75 Millimetre Water Seal Tubular Swivel Anti-Syphon (Silentrap) inchP inch Trap with Universal Outlet

75 Millimetre Water Seal.
Universal Compression Outlet suits all plastic, copper and lead pipe.
Anti-Syphon Valve neutralises negative syphonic pressure and eliminates gurgling.
Manufactured in polypropylene.
Conforms to BS EN 274-1:2002.

1.25 Inch SA10V
1.50 Inch SC10V
2 Inch SE10V

General
By drawing air through the Valve, the Silentrap neutralises syphonic pressure before it reaches the seal of the Trap and therefore provides the equivalent of a ventilated system without the installation of costly and unsightly ventilation pipes.
The Silentrap has been most rigorously tested and will not unseal, even under the most abnormal conditions.
The Silentrap should continue to be effective irrespective of the distance between the appliance and the soil pipe.
Operation.
Whenever syphonic conditions develop, the negative pressure causes the Valve to rise, allowing air to be drawn into the discharge pipe. The pressure is thereby neutralised before it can have any effect on the water seal within the Trap. On cessation of the syphonic action, the Valve closes, making the Silentrap air and watertight.
Advantages.
The major advantage of the Silentrap over Resealing Traps is that because the air is drawn through the Valve and not through the water seal, gurgling is eliminated and a much quieter discharge is ensured.
Eliminates the need for secondary ventilation.
Silentrap Valves are available on a wide range of Bottle, Tubular and Bath Traps.
Silentraps allow for greater flexibility in plumbing design.