Non-rising stem (NRS) gate valves are a type of valve generally used in underground fire protection installations. They are designed to control and direct the flow of water in underground fire mains. Unlike rising stem valves, the stem does not move upward, so the position of the valve cannot be monitored without an additional post indicator. UL listed and FM approved valves are designed and tested to internationally accepted safety standards.
Why NRS valves?
- Simple, reliable design: controls the flow of water reliably. Because the stem does not move vertically, installation and maintenance are easier.
- Low maintenance: since the stem does not rise under pressure, no extra space is needed for its movement, which lowers running costs and improves system reliability.
- Reliable in a fire: it plays a critical part in getting water quickly in a fire and helps bring the fire under control.
- Standards compliance: designed and tested to fire safety standards.
See also OS&Y gate valves and Volon.