This Rule 25mm Check Valve sits in the discharge hose on 800 GPH and 1100 GPH bilge pumps and stops water tracking back into the hull. You run it in a 25 mm or 1 inch line between the pump and the outlet so the bilge stays drier between cycles. That helps when the well is only 200–300 mm deep and every extra litre sloshing around makes the boat feel heavy.

The valve uses a compact marine grade plastic body sized to standard 25 mm hose so it clamps straight in without sleeves. Flow is set up for the 800–1100 GPH range so the pump can still push water to an outlet 1–2 m above the bilge. The gear is a smart buy for small trailer boats that cop regular chop along our 30–35 °C summer days. Fit it once and get out there with a drier bilge.

• Replacement 25mm in-line check valve
• Suits Rule 800 GPH bilge pumps
• Suits Rule 1100 GPH bilge pumps
• Fits standard 25mm (1 inch) discharge hose
• Helps reduce reverse water flow to bilge
• Compact body suits tight pump spaces
• Direct service replacement for worn valves
• Marine grade polymer construction
• Suitable for Rule bilge systems on small boats

Q: Can this check valve be used on any 25mm bilge pump?

It is made for Rule 800 GPH and 1100 GPH pumps that specify a 25mm check valve. Other pumps with 25mm hose tails may not match the intended flow or pressure range. For best results stick with the listed Rule models. That way the pump curve and valve resistance are set up to work together.

Q: Where should I install the Rule 25mm Check Valve in the bilge hose?

Install it in-line between the bilge pump outlet and the hull discharge fitting. Keep the valve in a straight section of 25mm hose to avoid kinks and restriction. Mount it where you can still reach the clamps for future servicing. Make sure the flow direction follows the arrow on the valve body.

Q: Do I need to service or replace this valve regularly?

Yes it should be checked as part of normal bilge maintenance. Over time debris and growth can affect the internal mechanism. Inspect it when you test the bilge pump and replace it if the valve sticks or leaks back. Fresh clamps and clean hose ends will help the new valve seal properly.

Q: Will this valve stop all water from returning to the bilge?

It greatly reduces backflow but some residual water in the hose may still drain. The main job is to stop the bulk of the column of water above the pump. That helps keep the bilge level lower between runs. Always combine the valve with regular checks of your pumps and float switches.

Gear suits Rule bilge pump installations that use 25mm (1 inch) discharge hose on 800 GPH and 1100 GPH models. Setup fits inline on the discharge plumbing between the bilge pump outlet and the hull outlet fitting. Kit works in marine bilge systems where backflow control is required on 25mm hose circuits. Equipment is intended for use with Rule brand bilge pumps that specify a 25mm check valve in the install instructions.