Alcaplast Bottom Inlet Fill Valve — A17-1/2"
The Alcaplast A17-1/2" is a bottom-entry hydraulic fill valve designed for installation in ceramic and plastic toilet cisterns. Engineered with a standard G 1/2" plastic shank, it serves as a universal replacement for failed or noisy bottom-inlet valves. The valve incorporates a hydraulic closing mechanism designed for smooth shut-off to eliminate water hammer, an adjustable float level for tailored flushing volumes, and a removable internal dirt filter to protect the internal diaphragm from incoming mains debris.
Identification & Technical Guide:
Brand / Manufacturer: Alcaplast (Alca) | MPN: A17-1/2" | Inlet Position: Bottom entry | Thread Size: G 1/2" (approx. 20.9mm outer thread diameter / standard UK & EU 1/2" BSP) | Thread Material: Technical Plastic | Working Pressure Range: 0.05 – 0.8 MPa (0.5 – 8 bar) | Acoustic Group: Class II (< 30 dB at 0.3 MPa)
Key Features
- Universal Bottom Fitment: Designed for ceramic and plastic close-coupled or low-level cisterns with a standard bottom inlet opening.
- Hydraulic Shut-Off: Closes smoothly against mains water pressure, minimizing hydraulic shock and pipeline rattle.
- Integrated Debris Filter: Removable mesh filter captures silt, limescale, and pipeline particulate before it reaches the valve seat.
- Tool-Free Water Level Adjustment: Threaded adjustment rod allows quick, precise calibration of the cisternal water line.
- Low Acoustic Profile: Compliant with Acoustic Group II standards for unobtrusive, quiet cistern refilling.
Installation & Fitting Notes
Thread Sizing Warning: This model has a G 1/2" thread (approx. 20.9mm outside diameter), standard for UK flexible tap connectors and standard cistern isolators. Ensure your supply pipe is 1/2" BSP, as continental Europe cisterns frequently use G 3/8" (approx. 16.6mm OD — model A17-3/8").
Tightening & Seal: Hand-tighten the plastic backnut securely against the base of the cistern, followed by a maximum of 1/4 turn with an open-ended spanner. Do not use excessive force or pipe wrenches on plastic threads.