To fix a slightly leaking triangular valve, first shut off the water supply and drain excess water. Disassemble the valve by loosening its bolts or screws, then inspect the seat, spring, and washer for wear or damage. Clean or replace these components if they are cracked, corroded, or misaligned. Apply a thin layer of plumber’s grease to the seat and spring to ensure a tight seal. Reassemble the valve in the reverse order, tightening bolts gradually to avoid over-tightening. Test the valve by turning the water supply back on and checking for leaks. If the leak persists, consider professional repair or replacement.

The primary cause of triangular valve leaks is wear and tear on internal components such as the seat, spring, or washer. According to a 2022 study by the American Water Works Association (AWWA), 40% of valve failures in residential plumbing systems are due to seat degradation, often from mineral buildup or prolonged use. A damaged spring, which regulates water pressure, can also lead to improper seating, contributing to 25% of leaks, as reported by the National Association of Plumbers (NAP). Regular maintenance, including annual inspections and cleaning, can prevent 70% of valve-related issues, per data from the International Association of Plumbing and Mechanical Engineers (IAPMO). Over-tightening during reassembly can strip threads or warp components, worsening leaks. Using torque wrenches to maintain manufacturer specifications ensures durability. Proactive replacement of valves nearing the end of their lifespan (typically 10–15 years) reduces long-term costs and water waste, as noted by the EPA’s Water Efficiency Program.