Brass float valve
Easy Height Adjustment: A simple clip or twist-lock mechanism allows for tool-free height adjustment.
Valve Type: The internal mechanism that controls water flow.
Piston/Plunger: Traditional design using a rubber plunger. (Older, less reliable).
Diaphragm: Uses a rubber diaphragm to seal the water inlet. (Common in older models).
Float Cup (Piston-less): Modern design where the entire valve body moves up and down with a cup-shaped float. This is the current industry standard.
Pressure-Assisted: Used in high-efficiency toilets, where it fills a pressurized vessel.
Inlet Connection Size: The thread size that connects to your water supply line.
Standard: 7/8 inch (most common in the US).
Other: Some may be 1/2 inch or 3/8 inch. Always check your existing supply line.
Height Adjustability: The valve must be adjustable to fit different tank sizes.
Range: Typically adjustable from 9 to 14 inches, with some models offering a wider range (e.g., 7"to 16").
Flow Rate: The speed at which the valve refills the tank.
Measured in gallons per minute (GPM). A standard valve refills a tank in about 60-90 seconds.
Shank Height: The height of the part of the valve that sits at the bottom of the tank.
Standard: Usually around 4 inches.
Material:
Body: High-quality, durable ABS plastic or brass.
Seals: Rubber or Silicone. Silicone is more resistant to chlorine and mineral degradation.