03/08/2026
🚨 Why is your water tank constantly refilling? Here's one common cause we often encounter on site.
Recently, one of our customers reported that their main water tank was continuously refilling without stopping. Our technician conducted an on-site inspection and found that the issue was caused by *small stones and debris trapped inside the non-modulating valve*.
Unlike a clearway valve, a *non-modulating valve* has a more restricted internal flow path. When debris such as stones, rust particles, sand, or other contaminants enter the valve, they can prevent the diaphragm from sealing properly. As a result, the valve cannot close completely, causing water to continuously flow into the tank. While the valve itself is not faulty, the trapped debris causes it to malfunction.
✅ How can this be prevented?
1. Install a Y-Strainer before the non-modulating valve.
A Y-Strainer is a simple and cost-effective solution that filters out stones, rust, and debris before they reach the valve. Considering that replacing a damaged diaphragm is much more expensive than installing a Y-Strainer, this small investment can save significant maintenance costs in the long run.
2. Install the non-modulating valve only after the piping system has been flushed.
During a new installation, we recommend using a temporary short pipe (spool piece) in place of the valve while flushing the entire pipeline. Once the system is clean and free from construction debris, install the non-modulating valve. This helps protect the diaphragm and ensures the valve performs reliably from day one.
At *Maxwell Valve*, we don't just supply valves—we help our customers understand how to maximise their performance and lifespan. Proper installation and preventive maintenance are the keys to reducing downtime and avoiding unnecessary repair costs.
📩 If you're experiencing similar issues with your PRV or control valves, feel free to contact our team. We're always happy to help.
